Blown Head Gasket Sealer Additive

Think you might have a blown head gasket? Watch this short video to see.

Dear Austin,

I saw your answer to someone below after searching for a good block sealer: “If they DO suspect a blown head gasket or cracked block you might want to try a can of K&W Engine Block Seal additive you can buy at your local auto supply.

Drain out the coolant, add the can of additive to your radiator and drive the car for about 500 miles, then drain out the water/additive and install the proper mix of coolant and water to the radiator.

I have had great success with this method. WARNING – there will be NO freeze or overheating protecting during this time, since there is no coolant in the radiator.

” I have been having symptoms of a blown head gasket , getting white smoke from the tailpipe, smells like anti-freeze, boiling overflow bottle that has a gas or oil smell.

I have used “KW Block Sealer” (problem came back) then, “Cargo Seal-Up” both and still the problem came back. What caught my eye was you mentioned leaving the sealer in the vehicle and driving 500 miles.

I have followed the manufacturers instructions on both products by letting the vehicle cool and then re-filling
> with new anti-freeze. Maybe I should do as you have done and run the vehicle with the (sealer and water only mix) for 500 miles? Will it run that much more hot do you think? (I live in central Florida).

Any help would be appreciate, as I am not wanting to junk the vehicle but cant keep using these sealers and have them fail either. Thanks much for any suggestions, Matt

Hey there Matt

I have had great success using the K&W block sealer as I mentioned, but not as the manufacturer suggests. You should be fine for 500 miles living in Florida. Keep me posted as to what happens.


1. Product name is K&W Engine Block Sealer (available at auto parts stores everywhere)

2. Remove ALL coolant from the radiator and engine

3. Add can of sealer to radiator and top off with water only

4. Drive vehicle for at least 500 miles (in total, not all at once if you want)

5. Drain out sealer and water mixture and install proper coolant and water mix to radiator


Park vehicle in a warm garage at night during freezing temperatures and watch your temperature gauge in summer months at idle.

Reader update

Just a quick note Austin to say thank you again. The 1995 Ford Escort is working fine after leaving the KW Blocksealer in for 1000 miles. I then drained and flushed and filled with 50/50 anti-freeze.

Will keep ya posted!

Please share this with your friends to you for all your help,


Another Reader Follow Up

Hi there: Just Thought I would let you know that the K & W Block SEAL worked great.

The leak stopped almost immediately and 2 years , 9 months and over 100,000 miles later, No leak from the crack or the heater core . The Truck has over 307,000 miles now and no major engine repair yet.

I recently had a head gasket leak it was most definitely burning coolant in #3 cylinder I could tell by the steam seeping out from around the air injection antler in # 3 cylinder and the steam at the exhaust and the lower compression in # 3 cylinder in addition it killed the spark plug from that cylinder and the plug was very tough to remove from the head the rest of the plugs were easy. It’s like its been leaking for a while.

So, Time for another $7.00 K&W Block SEAL treatment. Did that with a new fan Clutch and off we go no more steam seeping from that antler or out the tail pipe and run’s Smooth .

Thank you for your advice and the 500 mile trick K&W was an excellent choice. I am A Firm believer in this product Saves a whole lot of Money ,Time and Work.


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Posted in: Head Gaskets

656 Comments on "Blown Head Gasket Sealer Additive"

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  1. Bill says:

    There is however a thing called a dome pistons where part of it is shaped like the head but also has iindent for the valves so they don’t hit

  2. Bill says:

    And also think about this at the piston went into the head the piston rings would get caught on the roof of the block

  3. Bill says:

    Just to let you know the Pistons do not succeed the engine block repeat they do not go into the head I went to school for rebuilding engines which is called auto machine The Pistons will break off the valves the piston succeeded into the head there is no room for the Pistons does not go past head gasket

  4. wayne says:

    I am having an oil & coolant mixing problem but none of the other signs of head gasket failure. will this product repair my problem?

    • Austin Davis says:

      Sometimes it can, it would be worth a try if you have gotten the pressure test and confirmed there is an internal leak in the cooling system

  5. Pete says:

    Sorry I meant Austin

  6. Pete says:

    I have a 1998 Volvo S70 w/~130K miles. Just had the radiator replaced and the car ran fine for about a week. In the second week after the repair the check engine light came on. My mechanic (STS Tire)said the code indicates a head gasket. I watched your video for the symptoms. The car is missing (makes some odd grumbling noises) when I try to start it but then it runs fine. It is not losing any coolant and it can idle for 30 mins+ without overheating or even moving the temperature gauge past normal. STS said it is probably a minor issue related to head gasket at this point but the head gasket is the problem. The repair cost would certainly outweighs the cars value.
    2 questions –
    1. does my situation sound like a good fit for the K&W product
    2. Whats your opinion of the Dura-Seal ( product or its claims that they are the only ones out there who don’t use that water glass silicate stuff which they claim will clog your system

    Thx Pete

    • Austin Davis says:

      I would get a second opinion from your Volvo dealer before doing anything. Yes, could be a small head gasket leak….but you dont have any of the common signs to be 100% sure. K&W is what I recommend, and use personally and have never had a clog problem.

  7. Moocher says:

    Is it really necessary to pull the spark plug and the injector of affected cylinders when you have an internal combustion leak? I have a 96 3.8L Camaro and the plugs are a pain to get to. If so, do you recommend K&W FiberLock? I need to replace the plugs and wires, but I do not wish to put in the time unless I know that the leak can fixed.

    • Austin Davis says:

      Did you watch my video about K&W sealer? I dont pull plugs or thermostat, drain coolant and add sealer and water to radiator and drive for 500 miles, then drain out and refill with coolant.

  8. Paul White says:

    My wife has a 2001 PT Cruiser with 278K kilometers (173K miles) on it. We are having to fill the rad with water/antifreeze every 2-3 days because the liquid is disappearing. We have installed a new Rad Cap but that does not seem to have helped. The overflow reservoir remains at a constant full state at all times. We live in the Pacific Northwest and are currently experiencing temp in the high 20’s and low 30’s (that would be (90 – 100 Fahrenheit). There is no anti-freeze smell and nothing coming out of the exhaust that we are aware of. Your thoughts on what our problems may be and will the Bar’s Leaks products fix it.
    Thank you.

    • Austin Davis says:

      Sorry for my delay. You need to get a cooling system pressure test to help you locate the coolant leak. Do not use a sealer, you need to replace what is causing the source of the leak…like a water pump, radiator etc. etc. Does not sound like a head gasket leak from what you have told me.

  9. Steven says:

    My symptom started as a intermittent misfire on #1 cylinder. What was happening was I was very slowly losing coolant through the head gasket, with no over heating. Eventually the coolant got low enough that it did overheat. I did have steam out the exhaust a few times when first starting but it would stop and the engine miss would disappear. So I did the flush several times and am starting my 500 mile sealing drives. Sure hope it works! My dodge 4.7 only has 75K miles so not happy I have this problem at all, but nobody is ever happy except maybe the repair shop.

  10. William says:

    I have a 95 mustang that apparently has blown head gasket. We used Barrs thinking it didn’t work. The oil after changing is milky after driving 4 miles after changing it. So my question is can I use the k&w after the failed Barrs?

    • Austin Davis says:

      Sorry for my delay, cant seem to keep up with all the questions lately. YES, use the K&W sealer per my instructions. Make sure there is not a radiator restriction that is limiting coolant flow.

  11. Bob R says:

    Says to drain the K&W Metallic Seal and remove hoses to let dry 24 hours before putting coolant back in. I plan to leave the sealant in for 500 miles. Does it actually have to dry?

  12. Mustafa Hacili says:

    is oil loss also a symptom of head gasket problem?

    • Austin Davis says:

      Its possible, but pretty rare. Usually a head gasket failure produces a coolant leak inside the engine. If you do not have any visible EXTERNAL oil leaks but continually have to add oil then you might be “burning oil” inside the engine due to excessive internal engine wear. Try using thicker weight engine oil, and make sure the PCV system is working properly and the engine can “breathe”.

  13. Robbie Stamm says:

    Hello Austin,just wanted to let you know I was skeptical at first regarding the K&W product. Low price and your recommended usage was really easy to do. You see I have had a sealing problem since I installed some custom built heads back in the 90’s. The engine is a Ford 302 bored 30 over. After assembling the block and installing an Isky cam with Comp roller tip rockers on a stock set of exchanged heads (1978 engine), it ran good but used lots of oil because of the cheapo heads. So I was referred to a Ford guy for the custom heads mentioned above. As soon as the heads were installed using special Ford graphite gaskets, I test drove the car and upon pulling into my garage and lifting the hood to see if there were any leaks causing it to overheat. The upper radiator hosed popped off and sprayed hot coolant on me, the garage and the exes car. I now look like Fire Marshall Bill and soon was divorced. Sorry, I thought I would throw in some humor. (Lol).. My head guy checked for combustion in the cooling system and sure enough it was there. His fix was to pull the heads, install new gaskets and use special grade 9 head bolts and hardened washers. He also recommended torquing the bolts well past the manufactures recommendation of 70 ft.lbs. to 100! And it worked.
    Fast forward to the second decade of the 21st century therefore shortening this Novella somewhat. Well I took the Stang out of storage and decided to get it fired up only to find I had a misfire and traces of coolant in #7. I remembered prior to parking it for 20+ years it ran a little rough before retiring it. I pulled the heads, installed new Felpro permatorques along with new ARP head bolts and washers (Cleaned block threads too). I torqued the bolts to manufacturers specs and crossed my fingers. You see I had a total of 8 broken head bolts (4 on each head-yikes)!
    Fast forward another year (2014). I am still getting an overpressurized cooling system, bubbles and foam in the recovery bottle and the engine runs cool 165-185. It some times recovers the overflow and sometimes not. I checked the torgue and all were good. The radiator is a custom 4 row Brass, aluminum Flowcooler water pump and a good cap. I was sure, even with out testing that I was still getting gases in the coolant. I have decided to attempt chemical warfare to fix the problem. You see I am poor now and underemployed without health insurance. I want to recapture the thrills I had driving my car and get a little enjoyment from life. Everything I have tried so far has failed and I was ready to give up when I checked out your site, 1 more try. It was easy to flush out the high dollar crap that I had in it and go down to Checker (OReilys) and pick up the K&W in the can. I installed it after back flushing an already clean cooling system. And per your instructions I will be leaving it in for the 500 miles. I let the old 5 litre idle for 20 minutes and noticed no changes. Then I noticed it started to idle smoother and it gained a little more RPM. My hoses were not as ballooned out with that ready to pop off look. I rev’d it a bit and held it and the temp dropped about 15 degrees. Now I’m thinking maybe my Swan Song attempt is working. I shut it down and no overflow of bubbles and foam. Once cool enough to open the radiator cap I discovered no Mr.Bubbles in the radiator since it was about an inch from full. Yes my hopes are up.
    More importantly I would like to sincerely thank you for what you are doing for car nutz like me and people that just cannot afford thc cost of repairs and expensive parts. We need our cars for work or just for enjoyment but don’t need the frustration of wondering will this product work or can it be fixed for a reasonable amount of time and money. Now I can think more positively about continuing my cars evolution in this day of expensive everything and one day it may be just the way I want it. At least for now I will put the 500 miles on it and as it improves I will be smiling and dreaming of that paint job or set of big 4 wheel disc brakes.

  14. TomM says:

    Hi Austin,
    Well, I’m back. My son’s ’93 Honda is once again is going through water like crazy and is probably the blown head gasket. this will be the third time. First time, didn’t take. Second, lasted about 8 months. We did, exactly, what you said re the K-500 and was very impressed until he just told me about the reoccurrence.
    Any Suggestions other than doing it again?
    Let me know via my email as I need this asap to help himself. ๐Ÿ™‚
    Thanks buddy.

    • Austin Davis says:

      Hey Tom,

      Hummmm, are you sure you do not have an external leak anywhere? Did you get the cooling system pressure test done, have you done it this time for this issue…I would.

      If you are absolutely sure there are no external leaks, then the only thing you can really do is do the K&W process over again. This time, once you have put the 500 miles on the vehicle drain out the sealer mix and leave the radiator cap off overnight with nothing in the radiator…no coolant or water. If you want to go another step, remove the spark plugs overnight as well.

      That might help get some air inside to cure the sealer mix a little better. usually we never have to do it, the repair is permanent but something weird is happening with this vehicle so lets do it this time around.

      Keep me posted

  15. jneal says:

    Well I am going to try it on my 1988 Mercedes-Benz 190d. It has 242k on it and i have nothing to lose. It had a small leak into the combustion chamber. I will keep you posted on my results after the 500 mile period is up. I am skeptical, but it beats a $2,800 repair bill at this point.

  16. Ed says:

    Dear Sir,

    I live in the netherlands and like to buy and try K&W Engine Block Sealent. Now who sells it in Europe and I don’t want to pay ten times the US price!


    • Austin Davis says:

      I am not real sure, can you talk to your local auto parts store and see if they can order it for you, or buy it on Ebay and have it shopped.

  17. moses says:

    hi!my problem on my golf vr6 is i got thick mixer in water bottle and water come from tailpipe.

    • Austin Davis says:

      I am not sure I fully understand your question, but I would highly recommend you get a cooling system pressure test to see if you have an external coolant leak (radiator hose, water pump etc.) or an internal leak like a headgasket.

      If you are positive that you do have an internal coolant leak, then try the K&W sealer I talked about on this page and use it per my instructions.

      Keep me posted as to your outcome

  18. Chuck Varner says:

    Hey Austin. I have been doing something similar at my radiator shop. If the customers car is not worth the expensive repair of a head gasket or in most cases a new cylinder head I give the no warranty choice of your idea. But I fill cooling system with water and flush out coolant residue if the damage is between the water and exhaust port then I drain the system of all water and if the thermostat is fairly accessible I remove it and replace housing with a new gasket. (Note) if thermostat is buried and its a 2 hour job. Forget it. Or if the customer is doing it herself and not mechanicly inclined don’t remove thermostat. Then I mix the KW block sealer with hot water in a bucket stir and dessolve it well and fill the Cooling system back up with this mixture then top off with water. I usually tell them to drive about 300 miles bring it back for me to check it. If all is well we drain at the KW mixture and replace it with antifreeze. I have had great success with KW block seal.

    • Austin Davis says:

      Chuck, that is great! Thank you so much for commenting and giving us your approach and success story.

  19. John D says:

    I have a 95 Taurus and have been going through lots of coolant. Water mostly due to continual loss. It’s been going out the tailpipe! I have a question. I ve followed your recommendation and am going to leave it in for 500 miles. Question, as I let it idle for twenty minutes the top radiator hose got really hard and bloated. Is the radiator cap malfunctioning? Not sure why pressure would be building up? Any suggestions?

    • Austin Davis says:

      That can be due to a bad radiator cap, try replacing it and see what happens. If not, yes a radiator restriction could be the culprit. Keep me posted

  20. Todd McC says:

    Hi again Austin, just treated another volvo ’99 V70 xc
    that had a new head put on but they neglected to replace the water pump which was leaking pretty bad(constant dripping when parked when running a steady trickle!)Was skeptical that K&W would work on the leak but after complete flush of block and cooling system, I used about 1/2 of a big bottle(green nano stuff) 15 min later, leak was sealed no water dripping! Amazing!
    Have another question though same as an earlier one… got a MBZ 350 SDL diesel thinking of trying the sealant on it no water in oil but lots of white smoke out of exhaust and losing water. Also with radiator cap off the coolant will bubble out quite forcefully, almost shooting out from the pressure.
    Wondering if this type of head gasket leak might be fixable with K & W ? Thanks again for your time.

    • Austin Davis says:

      Great news, you are on a roll man.

      Yes I would try it on the diesel and see what happens. Have had other readers say it worked well for them. Keep me posted.

  21. TomM says:

    I just want to THANK YOU Austin!!! You gave me the information and reassurance via the emails and I can’t tell you what a blessing you are to those of us who are looking for an honest assessment of problems and resolution.
    I know it may get redundant for you as the same message is being told in different formats to folks… keep it up – you’re the best.
    Thanks again pal.

  22. Ted Hughes says:

    I followed your instructions here with my 1994 BMW 325 last summer. The car had a radiator full of oil and a badly fouled #3 spark plug. It ran hot after just 4 miles.I removed the #3 plug,started the engine and poured in the K&W. The repair was nearly instant! I left the K&W in for 605 miles,drained and added antifreeze back. Now after 7,800 trouble free miles…the fix is in! Thanks a million…or in my case thanks $1,650!

  23. Elizabeth says:

    Thanks. I will let you know how it goes.

  24. Elizabeth says:

    Thanks. We have had the cooling system checked and it is definitely a blown gasket. It is a 2005 Camry with 155k miles and I have heard this is an issue with that year.

    Just to clarify, we should get the K&W Permanent Metallic Block Seal? not the one in the green bottle(nanotechnology). Also, we should follow your instructions, not the instructions on the bottle. So, we just pour in with the mix of water and then drive until we reach 500 miles? No sitting overnight, etc…?

    Thanks again.

    • By Austin Davis says:

      I personally use the original version of K&w block sealer, but many visitors here have used the newer Nano version with great success so either one should be fine.

      My instructions are MUCH easier and in my opinion do a better job, so yes drain out the radiator and pour in water and sealer mixture then drive the vehicle for a total of 500 miles then drain out. The quicker you can put on 500 miles the better. No sitting or thermostat removal required with my method.

  25. Elizabeth says:

    I have a blown head gasket and we used the Bar’s seal a few weeks ago. It worked at first, but I am now starting to add more and more water each time I drive. I want to try the K&W and wish I would have seen your info before using the Bars.
    Question: Is it OK to use the K&W on top of another seal product?

    Thanks for the info.

    • By Austin Davis says:

      You will need to drain out all of the existing coolant/Barrs sealer/water from the radiator before you use the K&W sealer.

      ALWAYS get a cooling system pressure test (its cheap and fast) done first to rule the possibility of an external leak like a water pump, hose or radiator etc.

  26. Todd McC says:

    What it is Austin! No problems with the Escort
    driving it daily and used only about 1/3 of the bottle of K & W in this case works like a charm!
    Dude like I said you are the man.
    I am completely amazed by the results I’ve had so far
    anybody wants a testimony call me @ 805-765-1310
    Todd Thanks for your help !! like I said do your due diligence w/ overheating issues 1st.
    then you’re good to go

    • By Austin Davis says:

      Thanks Todd, glad to help.

      You are correct, if you do not fix the CAUSE of the overheating first you are wasting your time hoping the sealer will work. A blown headgasket is just the symptom caused by an overheating problem.

  27. TomM says:

    One Correction.. after cooling, we drained K&W per directions…. and opened the radiator cap and drain plug for air ventilation.

  28. TomM says:

    Hi Austin,
    My son has a ’93 Honda Accord Coupe which had/has a leaking water pump that resulted in a definite blown head gasket. looked at your site and tried the K&W. Did everything according to the directions and the white smoke has dramatically dissapated but still a little bit of smoke and some small drops of water out of the tailpipe. Also, it kept it’s temp but then would spike so we let it cool down, then added more water. Wanted to do the K500 but afraid of overheating so I drained the K&W and allowed it to dry for 2 days. Today’s the day. I’m going to drain the K&W and fill her up with water at first to see if the stuff worked and then go for it. The question I have is this, if there’s still white smoke coming out and drips out of the tailpipe, would you think it’s best to retry the K&W?
    You’re quick response is much appreciated and your site is fantastic pal.

    • By Austin Davis says:

      Thank you.

      You should be good to go. Fill radiator with water or water coolant mix and take it for a test drive. You might get a little smoke out tailpipe until the old coolant burns off inside the exhaust system.

      The sealer does a permanent repair, if it had enough time to find the hole and plug it.

  29. Todd McC says:

    OK Forget that last question, found out that we have a burn’t valve compression test was correct no oil in water or water in oil, no exhaust gasses in coolant
    apparently Honda cr-v needs valve adjustments frequently if they get too tight you burn valves(exhaust usually.)
    but I did do car #5. ’99 Ford escort zx-2 sport 125K miles. no overheating just blew that puppy!Had a little trouble flushing coolant system had to pull thermo. major water in oil, I might have to change to oil 2x after I drive around a little. If you don’t get all the coolant out does that affect the K & W treatment? Thanks Todd McC

    • By Austin Davis says:

      You really need to drain out as much coolant as you possibly can, although personally I just drain out radiator and heater hoses best I can and give it a go. Most of the cars in our shop that need to have the sealer have only been using water to begin with ๐Ÿ™

  30. Todd McC says:

    Hey Austin, Getting ready to go do car #5(Honda CR-V 1999 85k mi.) owner told that valves were tight check engine light on cyl. #2 compression 75 lbs the rest are 170 lbs no water or fuel on spark plug. Owner told he had a burnt/bad valve would need a valve job no overheating!
    I’m thinking head gasket, going to check coolant for exhaust gases. no water in oil. Looks like K & W candidate! Don’t know how the gasket would blow w/o overheating but maybe these cars have propensity?
    Thanks, Todd

  31. mary says:

    Does a particular brand/type of sealant (e.g. copper-based, other chemical, etc.) work better/worse with a certain type of engine set up? For example, a head gasket where the leak is the result of differing metals between the head and the block (and/or gasket)? (Apparently my aluminum head is causing the leak to be intermittent/inconsistent, but my mechanic traced the coolant to to the head gasket and I saw it as well.) (Also, coolant pressure test came up completely normal.)

    • By Austin Davis says:

      I personally have only had any real success with the K&W sealer, which is copper based. I don’t see why it would not work for you either and my suggestion is that you at least try it and see what happens.

      Although from what you have told me I am not really convinced that you have a headgasket leak….which SHOULD also show up in the pressure test.

      Before I spent any money, I would get a second option just to be sure.

  32. Todd McC says:

    Hey Austin, yes I actually advertise for that locally
    I’m a mobile mechanic by hobby more than trade.
    But have had reasonable success doing less complicated work(brakes, alternators, sensors, water pumps etc.)
    I turn down stuff that is too messy or difficult.
    Having over 25 yrs. as smallbusiness owner(carpet cleaning) I’ve had my share of mechanical issues between vans, machines and personal vehicles. Hence trial by fire as it were! The gasket sealer(That you use) is a great way to save a vehicle without dumping
    too much $$ and time into potential nightmares.
    So thanks again and I’ll keep you updated as well. Not much of a facebooker but will definitely order your ebook!:)
    Todd McC

  33. Jonathan says:

    Man, love this idea! Thank you so much. The comments from your readers really excite me that maybe there is a chance this will work for me too.

  34. Todd McC says:

    Austin car #4 done –and done–’96 Hyundai accent
    internal gasket leak new water pump/thermo, again exaust gases in radiator, water in oil ran it with K&W– within 20 min had sealed the leak. Oil Change and voila! Other minor issues with this car but NOT OVERHEATING! (which was the real problem w/o any other issues)
    You are THE MAN — people– listen to this guy he knows his shit.
    Todd McC

    • By Austin Davis says:

      Todd, sounds like you are the man! Maybe you should advertise for headgasket repairs in your area? I am assuming you are a mechanic or run a garage…or just happen to have alot of cars with blown headgaskets ๐Ÿ™‚

      Maybe you can “like” me on Facebook or what ever, I am not into social media like I should be. So many people are paying big bucks for something they can fix themselves.

  35. Don says:

    Dude, you really did save my car. I was about to scrap it because of a blown headgasket that I can not afford to fix. This stuff really worked. Thank you thank you.

  36. Sandy says:

    Thank you for everyone sharing their comments. I will try this sealer trick today and see if it fixes my engine. I can not afford to get it repaired at my mechanic. HE never mentioned anything like this as an option.

  37. Todd McC says:

    Hey Just to let you know– Toyota 4runner sealed it perfectly, volvo was sealed but he had some other overheating issues unrelated like you said….
    Did a 95 Honda ex w/ 150k mi. new rad., pulled thermo,
    flushed completely, water pump was a possible issue but so far so good , sealed it up no overheating now but definitely had a blown gasket(exhaust/gas fumes in radiator w/cap off) no water in oil though..
    That’s 3 for 3 !! you have to do the due diligence on
    overheating issues but This method works on internal gasket leaks every time. Kudos to you for this site and your assistance. Thanks again Dude!
    In response to the last posting yes there are many that have had success with this, read and follow Austins directions–exactly, eliminate overheating sources and you’re good to go…

  38. Eric says:

    Just what I needed to hear. I am pretty sure I got a blown headgasket, but my mechanic NEVER mentioned that there could be a cheaper alternative to his $1500 repair bill. I guess other readers of yours have had success with the KW sealer as well as you??

  39. Carl says:

    Im going to try the KW sealer trick like you suggest. I guess my only other option is $1500 in repairs. Fingers crossed. Thank you Austin

  40. Todd McC says:

    Thanks Austin, The volvo guy pulled thermostat and now its not overheating so not sure why 2 different stats would cause this problem– he poured another bottle of K&W in because we lost some during the first try(radiator hose popped off and
    had some air pockets that needed bleeding.)
    Told him to run at least 500 mi. before flushing out.
    Warned him of the same timing advance issue.
    Also have heard some good things about barr’s 1111 formula even sealing external gasket leaks(coolant).
    Thanks again. Todd

  41. Todd McC says:

    Hey Austin thanks for the quick response. yeah it’s definitely overheating bubbling, thinking it’s the lower hose thats collapsing, plus no coolant in there (water plus some residual K&W) I’m in CA it’s reasonably cool here– at least it stopped the leak though no white smoke no water in oil!! — will definitely update.
    But have another question, will K&W work on external gasket leak? if not are you familiar with another treatment that might(e.g. thermaweld, Barr’s 1111, etc.)

    Thanks, Todd

    • By Austin Davis says:

      K&W is for internal coolant leaks, and don’t think it would do any good for an external leak, actually I don’t personally think any sealer does.

      On the older large all metal radiators (not plastic or aluminum like today) I had a few successful radiator repairs using Bars Leak Stop, but everything else is a waste of time in my opinion.

  42. Todd McC says:

    Update on Volvo — can’t figure out cooling problem.
    owner claims it Wasn’t overheating before treatment.
    had system pressure bled to eliminate air pockets, new stat, checked hoses cooling fans are running as the temp goes over 1/2 guage, only overheats when running on fwy.
    Thinking lower rad hose collapsing maybe at higher speeds— I can feel decent pressure when squeezing upper rad hose and stat open.
    Would putting coolant back in help? This one has me a little baffled, no leaks heat core bypassed.
    thx Todd

    • By Austin Davis says:

      I have not had any problems using the sealer, no blockages etc. that people claim have happened…don’t see how it can happen.

      If overheating on freeway my first thought is not enough coolant flowing through radiator or not enough airflow across the radiator. Is something blocking air flow across the radiator? Radiator is new??? Right one for vehicle? Same core size as replacement? Same width etc. I would triple check that, sometimes you are given a 2 row radiator when you should have a 3 row core. Make sure the replacement is proper for the vehicle.

      If it is real hot where you are now, remember you do not have coolant inside so there is no boil over protection.

      Lastly, are you SURE the engine is running hot and not a gauge or coolant temp sender problem?

    • By Austin Davis says:

      One more thing. If this is an older Volvo with a distributor, make sure the ignition timing is not to far advanced. Can cause running hot issues.

  43. Todd McC says:

    Hi Austin, Just a note to say thanks again Toyota is running like a champ and I’m getting ready to drain the cooling system after 500mi. should I let it sit empty overnight for “curing”?
    Did a the treatment on a Volvo yesterday that had a larger internal leak(oil was milky, visible exhaust gases in coolant reservoir)–took a bit longer to burp system and seal the head almost an hour of run time, went to change oil and noticed some of the K&W had gotten into the oil as well looks whitish and goopy.
    but again seems to have sealed the leak, however still has overheated after treatment, will replace thermostat today, radiator is new, w.p. suspect. Also, Have you had any success with Diesel engines that had blown head gaskets?(e.g. MBZ 300D etc., Thank you again, Todd McC

    • By Austin Davis says:

      That is great news! I don’t mess with the dry out period, just drain it and refill it. I have not personally used the sealer on a diesel but have had visitors tell me it worked for them, so try it and keep me posted.

      Fingers crossed on the Volvo, rule out all other overheating issues. Electric cooling fans, external leak somewhere, thermostat, air pockets in cooling system etc. etc.

      Good work Todd.

  44. Todd McC says:

    Hi Again forget the previous post I just used the K & W on an ’87 Toyota 4runner head gasket blew after being replaced just 2yrs. ago! New rad, w.p. fan clutch no overheatng either. was told this is a common failure for these engines. Flushed radiator, cooling system with the prestone kit drained 2X then added the K & W as per instructions. Took about 20min. white smoke stopped coming out exhaust. Stopped after 30 min. and changed oil/filter. (Oil was milkshake color when draining.
    Restarted and white smoke again, waited less than 10 min. at idle and white smoke stopped again. Drove to store and back no smoke running smooth. I’m not over revving or pushing truck hard for the next 500mi.
    Will update after then. Thanks again for the info!!
    So far so good…

  45. Todd McC says:

    Hi Austin, have a ’99 5.7l Chevy Suburban w/150k and was going up a steep grade recently when suddenly started running rough no overheating but check engine came on.
    Came back home code’s read p0301 and 0303 was told by a not so reputable mechanic head gasket blew between cylinders 1 & 3. White smoke out of exhaust no external coolant or oil leaks, tiny bit of water in oil(inside top of fill cap). Is this type of gasket leak suitable for the K & W treatment? Many thanks in advance.

  46. Tyler C says:

    What would cause oil be in my radiator and my overflowed to smell like oil

    • By Austin Davis says:

      Its not too uncommon to see some oily residue floating inside the radiator and plastic overflow bottle, could an seep somewhere internally or left over from a previous repair to the cooling system.

  47. Tyler C says:

    Thank you for the quick response.. I bought a gasket combustion tester (with the blue fluid) and turned yellow in about 12 pumps. I’ve put probably another 100 miles since then and there was some coolant that was gone from the resivor.. But I looked inside my radiator and there was like 4 little grayish circles when I opened the radiator cap.. So I just ran some prestone radiator flush and I’m flushing my system as I type. So I think I might retry the test before I actually do the K&W sealant.

    When he did the pressure test I couldn’t understand why nothing was leaking out but then the head gasket test said it was bad?!

    • By Austin Davis says:

      I don’t like those combustion gas tests, to many false positive results for me. A pressure test if done correctly should tell you what you need to know, is there a leak either internally or externally. Yes, you can have a small “seep” of coolant internally to the headgasket with the engine running, but I don’t really think that is what is going on here.

      To me, it still sounds like a radiator restriction type of problem. Flushing does basically nothing but remove the top surface rust and crud. The bottom of the radiator is probably clogged up, and a new radiator is probably the answer. In the older days a radiator shop could disassemble the radiator and “boil out” the internal gunk. Most plastic radiators today, its cheaper and faster to replace them.

  48. Tyler C says:

    Hello Austin i was wondering your opinons on my situation. I drove about 60 miles the other day and my car started to over heat and was leaking from the bottom (near the radiator) and ive been driving the car for 2 days and no over heating.. I have all the signs of a blown head gasket.. White smoke from tail pipe, rough start up, bubbling radiator. I did a coolant pressure test and there was no leaks! But i do not have any coolant leaking to my oil.. Let me know what you think, thank you!

    • By Austin Davis says:

      So during the last 2 days the engine has not overheated, and you have not had to add coolant to the radiator???

      Usually when an overheating issue happens more so at freeways speeds, during long trips, pulling heavy loads, mountainous driving etc. the problem is due to a restriction in the radiator not allowing coolant to flow fast enough in the engine.

      If you had a headgasket issue I would expect that there is a lot of white smoke constantly out tailpipe, you are constantly adding coolant to radiator, engine missing and running rough due to coolant on spark plugs etc.

      The pressure test you did SHOULD have indicated a leak, if you really have a head gasket leak…a leak is a leak and the pressure tester would not have held pressure.

      Since you physically saw the coolant leaking, seems to me this pretty much has to be an external coolant leak, or maybe the engine overheated due to restricted radiator and the engine boiled over and coolant ran down the radiator….pretty common.

      I would re-pressure test, and double check the radiator for restriction, cooling fan operation etc. before I jumped to a head gasket BUT, if you really suspect that, try the K&W Block Sealer as I mentioned in this article.

  49. John Field says:

    Re: 1991 Eldorado 4.9,,,Drained the coolant and Used Prestone Flush and flush kit today,,took out thermostat,,ran the car with Flush in it about 10-15 minutes,Drained that out,,,then filled with water,,ran car again about 10-15 minutes,drained that water,added water started the car again,,this tme flushing witha garden hose in radiator while removing and tightening the cap on the T that was in the heater core supply line, the removed the cap and ran it till clean water came out,,Flush Done,,,reinstalled the 195 thermostat tightened all hoses and cap on the T provided with the flush kit,,I then mixed the K&W I bought at Walmart with 3 Qts Hot tap water as Instructions on can say,,Poured it in the radiator and added Hot tap water to fill it up ( the T came in handy on the Cadillac,it allowed me to burp the system,I also used a tall funnel om the Cadillac,It raised the water level so I could fill it) I started the car,put the Radiator cap back on and waited,( I thought there was no Hope,This car was Blowing water out of the tail pipe,A LOT of water,and I had Compression bubbles in the radiator) so I wait,,at around 10 minutes the smoke coming out of the tailpipe started to slow down,,at 20 minutes a little less,,at 30 minutes a little less at 40 minutes less,,at an hour less,, at an hour and 10 minutes it had almost stopped completely,,so I set the Idle up to about 2350 RPMs,,alot of white smoke so I leave it there after about 10-15 minutes it had cleared up,,so I drop it back to an idle for 10 more minutes ,,IT HAS COMPLETELY DRIED UP, NO WHITE SMOKE,,so I get in it and drive slow on backroads start and stop for 10 miles ,then I hit the Interstate and drive about 20 miles then I drive some secondary roads and romp on it quite a few times,,I get home after 50 miles,,Get out and it used Zero water, I was able to monitor the water temp and it always stayed well within the operating range,sorry this so long ,,but Cadillac owners Know on a 4.1,,4.5,,4.9,,or a Northstar you have to drop the whole motor out of the car, have Studs installed in the block, and heads planed to fix the head gasket,around 2500- 3500,,I will up date as I put more miles on the car,,I will Leave the K&W in for 500-1000 more miles if it holds up,,the car is cooling now,,I am In a Colder Climate,no garage,so I just bought a cheap ceramic heater at Walmart that I will put under the hood at night it has a thermostat and will keep the K&W and water from freezing,till I reach the 500 mile Mark,Thanks Austin ,this is the only post that made any sense,,and I read a bunch of them,,had I followed the Instructions on the Can,I would Have Been S.O.L. ,,It was still leaking quite a bit after 30 minutes,,Thanks Again

    • By Austin Davis says:

      Awesome! Thank you so much for taking the time to post what you have done and the progress. My only concern is, do you have a restriction in your radiator that caused the initial overheating and head gasket damage? Since its cold where you are, you might not notice a restriction as you would in hot weather.

      I would not be surprised that a 1991 radiator is full of junk and needs replacing, since flushing really only removes the top surface junk.

      Keep us posted if you dont mind, I am sure it will help the next guy.

      Merry Christmas

  50. Djgw says:

    Thanks for the fantastic resource Austin, some very helpful information. Wish I’d discovered your site earlier.

    I’m in Australia and while K&W Block Seal isn’t available locally, CarGo Metallic Seal-Up is and I’m guessing has a similar formula. I’ve just used it on a 93 Camry which initially had symptoms including a hot coolant smell after a drive along with gradually lowering levels in the radiator. This developed into an overheating problem with loss of coolant and after refilling, noticeable water vapor from the tailpipe while running on 3 cylinders.

    After a lot of research (and mechanics advising at least $1500 to fix) I picked up a bottle of Seal-Up and did the initial coolant flushing etc. before adding to the warmed up engine. I was concerned about the viability of running the engine for 30 minutes as directed – usually overheating occurred within 5 to 10 minutes. As the temperature increased I noticed a lot more steam than normal accompanied by smoke with a strong smell which billowed down the street and the engine began to stall at low revs.

    Things didn’t seem to be going so well with overheating before the product might work and what seemed to be bigger coolant leaks. Decided to carry on, released pressure in the radiator and topped up after restarting. After another 5 minutes, the engine started to run smoother at idle with reduced water vapor from the exhaust. Got the car onto the road and noticed the temperature was stable! After another 10 minutes, no noticeable exhaust vapor and idling on 4 cylinders.

    I kept the vehicle running in total for nearly an hour before switching off and draining the Seal-Up, had I found your site earlier I would have left it in for a lot longer. Anyway, so far so good, after letting the engine sit overnight I refilled with coolant and now the car is running better than it ever has.

    I’ll report back on outcomes and thanks to your site, know what to do in the future if similar problems emerge.

    • By Austin Davis says:

      Great info thanks for sharing with us. Be sure to rule out the initial cause of the engine overheating or you are just wasting your time trying to solve the damage that occurred because of the overheating symptom.

      If the engine overheats within minutes, I would be suspect of an electric radiator cooling fan that is not working or a radiator that is plugged up and restricted at the bottom. This car has a very small plastic radiator and they plug up very easily over the years. If coolant cant flow properly throughout the engine…it will overheat.

      Keep us posted. I am sure you can buy the K&W Sealer on Ebay and have it shipped to you if you still have problems and have solved the initial overheating problem.

  51. Phil says:

    GREAT website – and up-to-date! Just put in a new water-pump in my ’97 Buick LeSabre that I bought used 6 months ago (now at 87,000 miles). Just a small leak, no overheating problems. But – my neighbor (a mechanic) noticed water and white gunk on my oil filler cap. I know this model (GM 3800 engine) is known for head casket problems. But the neighbor said it could just be condensation. (The car is driven three miles to school, sits all day, then back home).

    It runs fine, I don’t think there is white smoke in the exhaust. The coolant drained was very clean. The oil on the dipstick looked like oil (not a milkshake), and two different mechanics have changed the oil in the last 4 months and did not mention anything.

    I am in the process of flushing the coolant system, and was about to add some K&W just in case (and using your 500 mile method) – but now I’m thinking if it is just condensation then I don’t need it, and it may just make something worse. (Sounds like folks have noticed a bit higher running temps afterwards?)

    Sorry for the long note! And no – I have not done a pressure test. Will a pressure test confirm if there is a gasket leak? Or does it just tell you that there isn’t an outside leak?

    Oh – one last thing – how much coolant loss might one see if it is a gasket leak?

    • By Austin Davis says:

      Hi there

      Well, you are correct that you MIGHT just be seeing some condensation which is pretty common on those vehicles but so are head gasket issues. I don’t think I would just add the sealer just because of this residue though. I would clean off the oil cap and see if it returns.

      The sealer will not cause any problems, so you are welcome to use it if that will make you feel better about the situation. Most, if not ALL problems people have with the sealer is due to the fact that they did not correct the original overheating issue BEFORE using the sealer.

      If the radiator is restricted with junk at the bottom, and not allowing proper coolant to flow throughout the engine, the engine will overheat and that overheating can cause the headgaskets to fail. The sealer will not correct the radiator restriction, it will only seal up any metal gaskets (head gaskets) or internal engine coolant leaks.

      So, you have to fix the problem of overheating before you can use the sealer, and many people fail to do that thinking the sealer is a magic cure all additive.

      Since you do not have any overheating issues, its up to you if you want to use it or not. If the radiator is low on coolant and you are continually adding coolant, yes get a pressure test to find the leak. it will also tell you if there is an internal leak as well as external like a hose or water pump.

      Some headgasket leaks are so bad the engine will not run at all, some are just minor seeps but enough to cause the white exhaust smoke.

      Hope this helps

  52. Paul says:

    Im wanting to try the head gasket seal on an 01 firebird v6. I’ve had a pressure test and all signs point to head gasket. Only issue I have is that coolant is bubbling out of the reservoir cap about ten seconds after i start car. Will this keep the sealant from working?

  53. Tim says:

    Sorry it had white fluffy smoke coming out from the side of the engine

  54. Tim says:

    Hi I have a 2000 nissan frontier with a v6 that belonged to my father it would occasionally get at little hot but no enough to be a problem and he had said that the radiator had a leak well the other day it over heated really bad and got into the red and we had to limp home put water in it as we went. So we replaced the radiator today and filled it up with water and coolant and it started right up so we shut it off to gather up tools when we went to start it again it was very hard to start and started puffing white smoke and it seemed to be coming out mid way down the passenger side of the engine the length of the engine so I would assume it has a blown head gasket I know it had pressure because when we checked it after the initial start to see if it need more coolant it was pressurized and hard to remove the cap
    I bought the kw with nano tech do you think it will fix it or do I have another issue besides a head gasket.

    • By Austin Davis says:

      Hi Tim,

      From what you have told me I do not suspect a headgasket leak. I would get a cooling system pressure test FIRST before you do anything. I would bet there is a heater hose, or freeze plug leak on that side of the motor leaking coolant on the hot engine producing the white smoke. Fingers crossed for something simple anyway.

  55. jobyboy says:

    I used the K&W Fiber Lock Head Gasket & Block Repair on my old ’91 Lexus and it did the job beautifully. However, sometime after I used it (late April) I realized that it plugged up my heating system. So I would turn it on and off every once a while hoping that it will work. Now it is cold and I need some heat and it is still not working. Car mechanic checked the heating system and said that “everything is OK, so try to use it and hope it will unplug.”

    Since it is not unplugging itself, what is the solution to unplug the flow again?

    • By Austin Davis says:

      I have never seen the product clog up anything…radiator or heater core (which is basically a small radiator inside your dash board). The product has copper flakes in it, which when they come in contact with the very hot combustion gases inside the cylinder will melt and seal the hole in the headgasket. the coolant inside the engine, radiator and heater core is not hot enough to melt the copper.

      I would suspect you either have rust buildup inside the heater core or there is a control problem on the dash board not allowing the blend door inside the dash to open up and let the hot air from the heater core inside the vehicle. Check the 2 heater hoses at the heater core under the hood on the passenger side of the vehicle. When the engine is hot, both of the heater hoses should be hot as well.

      If one is hot and the other is cold, then something is plugged up in the heater core, or a heater control valve is closed. You can use a garden hose to flush the heater core. Remove the two heater hoses from the heater and flush the core with the hose. If both heater hoses are hot, then you have a control problem inside the dash. If neither hoses are hot, then you probably have a stuck thermostat or possibly a restriction in the radiator not allowing hot coolant to circulate.

  56. Kas says:

    Hey Austin… I really dig your site! Thanks for everything.
    So, I followed your instructions. I’ve been told that a sign of head gasket issues is when fluid shoots out of the radiator neck when you press the gas. This has been happening even AFTER I put in the sealant as you instructed. I haven’t driven it 500 miles like you said only because I’m afraid to take it out on the road. I’ve let it idle quite a bit though (maybe an hour total) and it still shoots the sealant/water out of the radiator neck when I hit press the gas. Does this sound like an issue that sealant can’t fix?… or should I hit the road with it for 500 miles anyway? (It still overheats, by the way…. although it didn’t overheat in idle last time I tried). Thanks again.
    NOTE: the engine light is on and apparently gives a code for the O2 heat core sensor, or something (the Honda dealership wasn’t very friendly with me).

    – Kas

    1999 Honda Civic LX , 150.000+ miles

    • By Austin Davis says:

      Hey Kas, thanks for the kind words.

      When you step on the gas with the radiator cap off (especially on small cars like yours) it’s normal to get a gush of coolant out the neck since you are spinning the water pump faster when you do that.

      Take a sandwich, and a few gallons of fresh water with you and head out for a 2 hour road trip AROUND your house/city and let the sealer do it’s thing.

      Now, if you have a restriction in your radiator not allowing coolant to flow properly (which can also cause coolant to gush out the next because it can’t circulate through the radiator fast enough) then the sealer is not going to fix a radiator restriction, only a new radiator will solve that problem. And “flushing” does nothing to remove junk at the bottom of the radiator.

      The sealer will only “seal” a hole in a metal surface like a headgasket or internal engine crack. So make sure you are not experiencing overheating due to a radiator restriction, water pump leak, cooling fan failure etc. etc. and not just guessing at a headgasket leak. The sealer will not hurt anything so since you already have it in, might has well put on the 500 miles, but if the engine is overheating at freeway speeds and there is no coolant loss or white smoke out tailpipe or loss of engine compression…I would bet you have a radiator issue.

  57. LilEngine says:

    I just wanted to submit an update- I last posted 11/10 and 6/10! My car is still running fine. It still has not had a problem starting and I’ve taken it on some long trips without any issue. It does leak a little more coolant than the average car and it is not an external leak (not sure where it’s going). It’s been 2 years now since I did it and happy to say this fix is still holding up. Thanks! –just a note, I did drive that hot 2010 summer in Iowa for 1000 miles with the stop leak in it.

    • By Austin Davis says:

      Awesome, thanks for the update. I get tons of emails (got another today) telling me of their success with the K&W sealer and a headgasket leak that it solved. Keep em coming.

  58. melody says:

    Thanks a bunch for all the good info you have on this site.I Not too long ago went to jiffy lube for a oil change. bad idea. they drained the oil and didnt bother to replace it. last night i did my tuneup and oil change on my own. i got the white smoke after i did all this so i hope its just runoff or something from the coolant or oil.

  59. Tom says:

    Austin…thanks for getting back to me. Yes, both the radiator and the cap are new, as well as the thermostat. Pep Boys told me that they did a pressure test, but said there was no indications of problems, other than the fan clutch, which was also replaced. Firestone did the dye test. It overheats during both in-town and highway driving, with no signs of external fluid leakage, but once some of the coolant is depleted, the temperature rises quickly and makes the reservoir look like a boiling teapot. You’re right, I didn’t mention having to continually add coolant, but that’s exactly what’s been going on. I would guess I have to refill the reservoir completely for every 30 to 60 minutes of driving. As I reported previously though, no white smoke, oil in water or water in oil…at least not yet. Any advice would be appreciated, thanks again.

    • By Austin Davis says:

      Hummm, ok. So adding fluid that often does concern me. I would visit the local dealership or find a local “real mechanic” first and start from scratch…pressure test, block check etc.

      I would expect to see white smoke and have an engine miss adding that much coolant.

      After you do that, and things look toward an internal leak, yes try the sealer, but use it as I instruct on this page not on the can instructions.

      Keep us posted will ya?

  60. Tom says:

    Thanks Austin, very helpful information on this page. Here’s the story…my ’03 GMC Envoy with 160K began overheating about three weeks ago. I replaced the radiator, cap and thermostat and refilled it with 50/50 water/coolant. It started overheating again immediately after I got out on the interstate. I pulled over, let it cool down, refilled it with water and limped home. Next, I took it to a shop (Pep Boys, grrrr!) and got a coolant system check. They said there was no block/head leak or plugged catalytic converter, but that I needed a new fan clutch. They installed a new one and refilled the fluids, but when I got it out on the road a few days later, the overheating returned (it did take longer for it to start overheating, though). Yesterday, I took it to Firestone for a second opinion. The tech conducted a block test and reported the following: “Diagnostic Codes P0014, 1221, 1271, 1481, 1482 and 1635. Block Test positive – not bright yellow, but close – greenish yellow. Engine failure or gasket. Most codes relate to fan clutch.” Checking today, there’s no water in the oil, the water in the reservoir is clear but low, and there’s no sign of white smoke from the tailpipe on start up. I have an extended warranty on the motor and tranny, but of course, it doesn’t cover gaskets, only the block and internally lubricated parts. Should I spring for a warranty evaluation at the dealer, or head straight to the nearest parts store for a can of K&W?

    • By Austin Davis says:

      The radiator is new? Have you had a cooling system pressure test done? I’m assuming it over heats most at freeway speeds? So far I am not convinced of a head gasket leak but the sealer is cheap and won’t hurt anything if you really think there is an internal coolant leak, but you did not mention havin to continually add coolant?

  61. dave says:

    So i have a 2001 ford Taurus 3.0 with the overhead valves. it over heated recently and i have exhaust coming out the radiator cap, i have water in the oil and white smoke. today i pulled the intake off to have a look at the valves to see if they were damaged at all and the weren’t. while putting back together i tested to see if i had water coming out the spark plug holes and i do.i have used the cargo brand of additive before and it work when there was exhaust coming out the radiator. what i am wondering is do you think it is worth a try with the k&w product and if so i have already bought the newer bottle that doesn’t call for just running it through and draining it. then letting it dry. it say to just add it, run it and keep it in there. keep it in the coolant system for continued protection. if i do try this would i run it with out the spark plugs at first or just leave them in and go with it? and hope it doesn’t mess up with the water in the cylinders…more or with water coming out the spark plug holes should i get the kind that calls for you to ad it then drain it and let it dry so maybe the water stops coming in the cylinders. i am try to avoid pulling the heads off cause with this car it is cheaper to get a used motor than buy or testing a head. thank you for your time

    • By Austin Davis says:

      Well, at this point I would definitely try the K&W sealer and use it AS I DIRECT on this page, not as the can instructions say to use….I have had much better luck doing it my way, and its much easier too. Although you might end up pulling the heads and getting a valve job done to correct this problem.

  62. Harry says:

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    are meant to be shared across the net. Shame on the
    search engines for not positioning this post upper! Come on over and
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  63. jonas says:

    Was very happy to find this site – you’re doing an excellent thing for people!

    However, perhaps I should have found it a moment sooner as I’ve just finished draining the K&W/water mixture from my radiator after carefully following the instructions. So, I didn’t run the vehicle (’96 Corsica)for the 500mi as you suggest as it states on the can to not rev or drive with it in there. The engine started overheating during my idle stage of the process which I then turned off the car, and restarted it after cooldown. It did not even get past the 1/4 mark on the gauge during the 2nd idle which gives me hope. So, do you think I’ll be alright after the curing stage, or should I do it again?

    • By Austin Davis says:


      well, I would go ahead and let it cure as the can suggests, but if you still have white smoke out the exhaust, overheating, coolant loss etc. then I would do it again my way and see what happens.

      Make sure your electric cooling fan is working, there are no external coolant leaks, and the radiator is not restricted at the bottom with rust and mineral deposits.

  64. Toddo says:

    Hi Austin
    I have some problem over car heating on my BMW M3, Would this product can work with my car?

    • By Austin Davis says:

      Yes, as long as you have ruled out ALL other possibilities, gotten a cooling system pressure test and really trust the mechanic’s diagnosis.

  65. dan simpson says:

    I have a 93 probe gt and drove it in high water, hydro locking it. I pulled the spark plugs and turned it over many times clearing the water out, changed the oil twice new air filter and replaced the plugs with new ones. The cars ran fine until i took it for a drive. Now it seems to misfire really bad stalls when not giving it gas, and has a lot of white smoke out of the exhaust. I’m thinking head gasket? Will K&W work for this or am i up the creek? Thanks

    • By Austin Davis says:

      IF the engine sucked in water through the intake/air filter then you most likely bent a valve or two inside the cylinder head. The sealer works really good for repairing torn headgaskets due to over heating issues, but will not repair a bent valve. If you really like this vehicle, I would pull the cylinder head, send it to a machine shop and get a full valve job done. Probably cost you about $1500 or so it you paid someone to do all the work.

      If you did the cylinder head R&R, then the machine shop charge would probably be about $150-225. Its a lot of work, and there COULD still be more internal engine damage.

      If water got inside the vehicle under the carpets and wiring and computer, or water inside of the transmission….I would cut my losses and sell it as is.

  66. Rick says:

    I have a 1999 Honda civic ex recently replaced thermostat and radiator it still overhets but only wh3n not in idle a mechanic did a pressure test and said there was no leaks lately the overflow tank has been boiling should I use the k&w thanks – Rick

    • By Austin Davis says:

      I recently made a video about common overheating issues, just like this. I would suspect you have a restriction in the bottom of the radiator not allowing coolant to flow fast enough through the engine. Replacing the radiator is the answer, flushing will not help. Ask your mechanic to double check this for you. I would not use the sealer in this situation.

      Overheating problem video

    • By Austin Davis says:


      I answer TONS of email questions a day and I overlooked in your email that you had already replaced the radiator. Sorry, in that case I would make sure all air pockets have been bled out of the system and the system is holding pressure. You should not be able to easily squeeze the upper radiator hose when the engine is hot, if you can I would suspect air in the system, lack of coolant in the system or a faulty radiator cap or some other leak.

      Watchthat video I sent and see if that helps

  67. Bryan says:

    My 06 quest is using a small amount of coolant, I already check the oil and it looks good. The problem is that every time In cold start i saw white smoke comming from the exhaust pipe. smokes about 1 minute and after that no more smoke. sometimes it smokes and sometimes doesn’t smoke. ( 80% smokes ) the smoke smell funny ( sweet ) no like burning oil or gas. last week it starting to get higher 2500 rpm when start and more white smoke but after 1 min. the rpm goes normal and no more smoke. Do you know if a bad Pcv valve cause white smoke ? Im trying to test the Pcv valve, but it’s to hard to access their location. The van is running good in the city and freeway.

    • By Austin Davis says:

      Hi, first thing i would do is get a cooling system pressure test to rule out the possibility of a blown head gasket type of issue. Coolant when burned does have a sweet smell to it, and it will cause white smoke/steam out the tailpipe. sooooooo, rule that out please.

      It is pretty common to see SOME white smoke coming out the tailpipe, especially on cold days. If you rule out the possibility of a head gasket leak, and you are still having to add coolant you MIGHT want to try the head gasket sealer like I talked about on this page. It wont hurt anything, but it might stop a small internal coolant leak you MIGHT be having.

      I dont think the PCV has anything to do with it….a worn catalytic converter could be the culprit, but it would not have any bearing on why you are adding coolant regularly.

  68. buster says:

    My 03 suburban is using coolant cant find leaks doesnt smoke or run rough except first thing in the morningg for about 30 seconds oil is not milky but is sludgy any suggestions

    • By Austin Davis says:

      Definitely get a cooling system pressure test, and I would probably also do a compression test on each cylinder just to rule out any internal engine wear or internal coolant leak like from a head gasket leak. If you want to try the K&W sealer, go ahead, it won’t hurt anything but might help in this situation. Use the sealer as per my directions on this page, not on the can itself…just my own preference.

  69. Rick says:

    hi, great website. I just had an oil change and air cleaner replaced in my 03 Aztek. i’m traveling down the hi-way, a red warning light starts flashing high coolant temperature, and temp. guage rising fast in red zone. but hopefully shut the engine down before any damage.
    I didn’t notice any coolant or oil leaks after I stopped, but noticed the engine coolant reservoir had debris and a brownish color.
    Mechanic stated a Blown Head gasket by a coolant system pressure test; stated the blue fuid test agent turned yellow. Mechanic stated car does not have water in oil but the engine coolant discharged back into the coolant reservoir for the debris and brownish color.
    I love my car, don’t want to sell for scrap, would this be a candidate to try the k&w sealer?


    • By Austin Davis says:

      Hi thank you. Well I am glad to see a mechanic did a cooling system pressure test!!!! Although the blue dye you mentioned is usually part of a “block test” which is different from a pressure test, so ask what he really did. A block test uses dye to determine if there are hydrocarbon gases in the coolant, which would indicate a possible internal combustion chamber problem.

      Problem with the block test is I have found them not to be 100% accurate. Pressure testing the system with a hand pump is the best way to check for internal and external leaks, as is a “compression test” on each cylinder. If you find a pressure test was not performed, do it.

      Now, I am still not convinced that you have a problem with the headgasket from what you told me….possible, sure, but I would like to rule more stuff out first.

      The sealer works great, and would be a great option for you as well but it is a last resort option and I hate to see people rush to use it without doing more investigation first.

      The debris and brownish coolant you see is most likely coming from the bottom of the radiator (rust, mineral deposits etc. etc.) and that debris is most likely still built up at the bottom of your radiator and the radiator is probably due for a replacement. Flushing does nothing, so don’t bother. I would ask your mechanic to check for a radiator restriction first, and replace as needed and see what happens.

      If you are absolutely sure the radiator is not restricted, then proceed with the sealer as per my instructions on this page not that of the can…in my opinion and testing my directions work much better with less work.

      I am betting a steak dinner that you have a restriction in the radiator which caused the engine to overheat and boil over all that rust and debris into the overflow bottle. If you do replace the radiator also replace the thermostat which overheated and could be damaged from doing so.

  70. Anonymous says:

    great website here

  71. Rick Gonzales says:

    I have a 98 Subaru Legacy which has a known head gasket recall/history. I travel 200-500 miles a week. I change the oil every 5000 miles with Motorcraft 5-30W Syn-blend. Currently, the car is running great. I was looking at my repair history and in January 2012 my mechanic added 1/2 gallon of antifreeze. Last week, I checked the overflow tank and it was empty. Looking at the valve covers, I can see evidence of corrosion and oil leakage. Yesterday, I cleaned the engine so that I could look for leakage.
    In the mean time I picked up a new version of K&W Head Gasket & Block Repair with Fiberlock and Cool-x conditioner. So I’m wondering if anyone has done your 500 mile procedure using this new version.
    Thanks in advance, Rick

    • By Austin Davis says:

      Before you do anything, get a cooling system pressure test to determine if there is a coolant leak either internal or external. Not too uncommon to see movement in coolant bottle from time to time depending on the engine temperature, so that is not an accurate gauge of what is really happening inside the radiator and engine.

      Yes, these vehicles do have some issues with internal coolant leaks, and yes some of my readers have used the new version of the sealer with success.

      Usually a headgasket leak will leak coolant internally in the cylinder, thus causing steam out the tailpipe. Rare to see coolant leaking externally from the headgasket visible to your naked eye.

      If you still suspect a headgasket leak, try the sealer but I would still use it as per my instructions on this page not those on the can….just from my personal experience.

  72. Jodi Lowell says:

    I have a 96 Mustang which a week ago the check engine light came on and the temperature dial fluctuated.Went to a mecahanic who said it looked like air bubble..he flushed the radiator which is a month old and everything was fine for 3 days when check engine light came on again.No overheating at all…back to the mechanic who said probably a cracked head oil in coolant or coolant in oil and no white smoke,,but coolant was indeed evaporating.No visible outer leaks.He kept the car overnight and today told me he used a head gasket sealer instead of pulling the engine and replacing the gasket which I originally wanted.What can I expect from this repair? $40 is all he charged.I am suspicious

    • By Austin Davis says:

      This sounds very fishy to me. This is what I would recommend you do first.

      1. Get another mechanic, a real mechanic
      2. Get a cooling system pressure test done, which will determine if there is an external leak or internal leak like a head gasket….which I dont think you have from what you told me.
      3. Only use the K&W sealer after you are 100% positive you have an INTERNAL coolant leak

      The check engine light…if YELLOW in color would indicate there is a problem with the emissions system or some other sensor problem with the engine, not an indicator of a head gasket leak.

      The RED engine light does indicate an overheating or low engine oil type of problem and should be investigated further.

      Sounds like you have an external coolant leak somewhere and the pressure test will help you locate it and repair it.

  73. Daniel says:

    I have just returned from the mechanic doing the coolant test on my 200,000 mile 1997 Taurus. Blown head gasket he says and questions whether it is even worth it for me to spend the $1000 or so to fix it. The car overheats easily, runs like it needs an urgent tune-up, white exhaust smoke out the tailpipe while it drains all the coolant after 10 mins of driving and NO chocolaty oil yet. This sounds like the perfect scenario for the K&W Engine Block Seal additive 500 mile fix. Yes?

    We are poor and if we can get a few months driving out of this car we could save for a replacement and be fine.

    Should I use the K & W product and where do I put this product in?

    Thank you for your help.

    • By Austin Davis says:

      Well, it would be worth a try, its cheap and easy to do. I would not have my hopes set too high though, if you are burning coolant that fast it’s probably going to require removing the cylinder head and replacing the headgasket…which I would guess would cost more like $1500+++ once its all said and done.

      You need…or should follow the instructions I give on this page not as described on the can. It goes in the radiator.

  74. Anonymous says:

    New to your blog. Stumbled upon it browsing the web.
    Keep up that the great work. I am hoping you update it regularly.

  75. jeff says:

    i have replaced the headgaskrt in a 2002 altima and there is still white smoke pouring out of the tailpipe what can i do to stop this from happening

    • By Austin Davis says:

      First off, get a cooling system pressure test to make sure that there is in fact an internal coolant leak. If there is, I can only assume that the cylinder head is warped and the head gasket is not sealing properly or there is a crack in the cylinder head…or the engine block.

      You can try the K&W sealer that I talk about on this page, but that is really a last resort…but its cheaper than redoing the headgasket job. Use the product as I mentioned on the page not as the can directs if you decide to go that route.

  76. Jorge says:

    so i drive a 99 civic ex with a d16y8, my car had been overheating but not to i replaced my thermostat and when it was replaced brand new the over heating was worse than before. So i replaced the water pump due to it had been leaking water/antifreeze. After replacing water pump it would still over heat. I replaced radiator and still over heats but now it idles at about the red line when hot…before it would pass the red line on temperature to about the H. maybe i can use that K & W sealant. im thinking its the head gasket; any suggestions?

    And as ive checked i am not leaking anymore.

    • By Austin Davis says:

      Does it run cooler at freeway speeds? if so, I would assume that the electric cooling fan at the radiator is not working. Check the radiator cooling fan!

      I would also make sure there are no air bubbles in the cooling system that needs to be bled out. Last thing I would do is make sure the engine is actually over heating and this is not a gauge problem. One thing that is a little strange is that you said it ran hotter since the new thermostat. You should be using a 195 degree thermostat.

      I suppose you could have gotten a defect “new” thermostat…rare, but possible. So before you decide to use the block sealer (which is fine as long as you rule everything else out) I would replace the thermostat again just to rule everything else out.

      If you do use the sealer, I suggest that you use it as per my instructions, not that of the can…which I have NOT had much success with. Keep me posted as to what you find.

  77. JT says:

    Hi Austin,
    I’ve got a 1993 Toyota pickup with the 22RE 4-cylinder. The water pump failed and unfortunately the motor got real hot. I replaced the water pump, thermostat and radiator cap. It ran OK for about a month, but was using coolant and pressurizing the cooling system. No visible water in oil. No visible water or white smoke out the exhaust. I suspected an internal head gasket leak.
    Just the other day, the motor began missing and making a loud knocking noise under load. Not a pre-detonation knocking noise; but a much louder knocking. I suspected a significant amount of coolant/water was getting into one of the cylinders. I limped the truck back home and pulled the spark plugs. Cylinder #3 proved to be the culprit. When I crank the motor over without the spark plug a significant amount of water shoots out the spark plug hole. I suspect the loud knocking under acceleration was the cylinder filling with water/coolant and attempting to hydro-lock. Do you think the K&W Block Sealer would work in a situation like this? I appreciate your time.

    • By Austin Davis says:

      If you have water coming out the spark plug hole, its pretty much toast. I would remove the cylinder head and send the head to a machine shop and have a valve job, resurface, and magnaflux done to make sure the head is not cracked. You will need to buy a headgasket seal kit, and the machine shop will probably need to have the valve stem seals to complete the job. I get charged about $125-$160 from my machine shop and it will take you about 6 hours total in labor to remove and replace the head, and the gaskets.

      You will get a much better job doing it this way and its really not that big of job on this simple engine. I would also send out your radiator or replace it because you do not want a rust/calcium restricted radiator to cause overheating in the future. On this old of vehicle I would expect the radiator to be some what restricted at the bottom which can not be flushed out.

      I would not waste my time with the sealer on this situation……although, if you really want to try it it wont hurt anything but seriously doubt it will help.

  78. Anonymous says:

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  79. Thecarys says:

    I used the K&M block seal to quick fix a crack in the block. It seems to have worked since I’m getting no more coolant in the oil. Problem is, truck keeps trying to overheat. If I take the thermostat out it will not overheat, so I thought maybe the thermostat was bad. I tested it and the thermostat is working fine. Why is my truck overheating after using the block seal? Help…

  80. bruno says:

    You know I have the “check engine” light on but I was told it’s probably a smog issue. And, no, I don’t have those issues you listed. So you are saying get a cooling system pressure test. But, if anything, it’s mostly likely a radiator problem.

    • Austin says:

      I think you have a lack of coolant circulating in the engine, this can be due to a restriction OR it could be due to an air pocket in the cooling system. I did not mention that before, but if you did not have this issue before the water pump replacement there could be an air bubble in the cooling system which is affecting coolant flow. Either case I don’t think this is a huge problem. I would get a professional mechanic to check this out for you before you spend any big money.

      1. Pressure test for leaks
      2. Check coolant level and make sure there are no air pockets
      3. Check for a coolant restriction

      Hope this helps

  81. bruno says:

    Hello, last week, before I changed the water pump, I had a water leakage problem and bubbling in the reservoir. I had a pully belt and water pump replaced. Things were going well for 3 days then I started to hear
    bubbling again in the reservoir. This time there’s no water leak because I made sure to check often. Now the bubbling happens when I use the car a lot and also, sometimes, when I drive up a hill, I get rattling sounds. Not all the time but when it’s warm and the car has to make more of an effort. I drive a Nissan Altima and a mechanic told me that Altima’s are notorious for blown head gasket. Do you think I should try the k&w sealant?


    • Austin says:

      You did not mention any of the classic signs of a headgasket failure…check engine light on, engine missing and running bad, lots of white smoke out the tailpipe, continually having to add coolant etc. etc. I would be more suspect of a restriction in the radiator from what little you have told me. Think of a radiator like this…you go out and try to run a mile as fast as you can, but you have your hand over your mouth so you can only breathe from your nose.

      You will collapse, you need more air. A restriction in the bottom of a radiator is the same thing with the coolant flowing through the engine. If you have a restriction the engine cant get the coolant it needs, so it overheats….and the problem gets worse the faster the engine is going or more loads placed on the engine…like going up hills. If an engine gets hot enough it will clatter, like an older car running on bad gas.

      Get a cooling system pressure test FIRST to rule out an internal or external coolant leak, if no leak, check the radiator for a restriction. the top and bottom of the radiator should be somewhat the same temperature when the engine is hot. if the bottom radiator is MUCH cooler than the top, I would suspect a restriction and a new radiator is the cure. Flushing does nothing, dont bother. A car with more than 90,000 miles would not surprise me to see a restriction due to rust and calcium deposits. Your radiator is very small and thin and will clog easy if you dont change the coolant often enough to keep it clean. Understand? DO NOT use the sealer unless you are absolutely sure about an internal coolant leak.

  82. Jim says:

    I have had over heating issues off and on with my 94 BMW 325i, I would constantly be adding coolant however I could never find the leak. At cold start I do get a puff of white smoke from the tail pipe. Would this product be compatible with my car?

    • Austin says:

      You really have to get a mechanic to pressure test the cooling system to see if there is an internal or external coolant leak. This is a simple and cheap test that can be done while you wait. I would not use the sealer or ANY product until you are positive you have an internal coolant leak like a headgasket…if you are sure of that, YES the K&W Block Sealer I talk about is the best thing I have found, if you use it like I suggest. But hopefully you have an external leak like a radiator hose, or water pump.

  83. Janell says:

    Hi Austin,

    I’ve been reading your posts all morning, and want to clarify specifics. I have a 2001 Chrylser Sebring LXi, 3.0L engine.
    Have had problems with the heater for 2 or 3 years, hot when rpms are over 1.5, but cold at idle. Several mechanics have tried to fix (replaced thermostat, radiator cap, flushed heater core, actuator door seems to be working) but to no avail. Recently started overheating but temp guage goes down with engine compression (i.e. shifting to lower gear). Then, started sucking down antifreeze with white smoke and antifreeze from exhaust. Mechanic pressure tested and it failed the block test, so suspects either head gaskets or cracked block.
    The engine still runs great. Would like to keep this car on the road, so am going to try the K&W per your instructions.
    Based on what you’ve said previously, I know I need to find what caused the problem in the first place, so thinking I definitely need to replace the radiator.
    Long story, but finally the question: How relative is the heating problem, or how might it have contributed to the failed block?
    Any other things I should be thinking about?

    Thanks for your time!

    • Austin says:

      Hey there! Yes, I think from what you have told me I would be highly suspect of a radiator restriction…and replacement is probably the cure. The heater is not hot at idle because there is not enough hot coolant/antifreeze being circulated throughout the engine. My first inspection would be to check the coolant level…I bet it’s low, then I would pressure test the cooling system for internal (headgasket) and external leaks (radiator, hoses, water pump etc.), then I would check the radiator for a restriction.

      The top and bottom of the radiator should be about the same temperature when engine is hot…top and bottom of radiator should be pretty hot/warm….not cold on the bottom. I would replace the radiator FIRST, drive the vehicle a while and see if you still have an issue with smoking or overheating….hopefully you wont. If you do, yes the K&W sealer used as I direct works great, but only has a last resort should it be used.

  84. Shell says:

    Hi, I just got done flushing out the Antifreeze 6 times to get it really really clean and have just finished running the motor North star for 25 min started to blow out the overflow so I shut it down . If I start it and rev the engine it blows out the over flow tank I have a compression in the coolant . Have you seen this work On my problem?

    • Austin says:

      I would get a cooling system pressure test FIRST before I did anything on this vehicle, you need to prove there really is an internal coolant leak before you just add this product to the radiator. I have used this product on a Northstar a few years back, and it was successful. You could just have an overheating issue, like a restriction in the radiator, or an electric cooling fan not working that is causing the engine to overheat. Once it overheats it will boil over into the overflow bottle. This product will NOT correct a problem like that, it is for sealing internal head gasket and internal engine cracks that are leaking coolant.

  85. Randell says:

    I have a 2002 Deville, I put KW in it with water for 500 miles and it stopped leaking and getting hot just as you said. However when I drained my Water/KW and replaced with Coolant, now my reservoir is a dirty brown color not a green coolant color. It is not getting hot, and I haven’t had time to drive it very far to see if it’s leaking, but I filled the oile, and it seems as the oil stick is almost a quart low. Do you think it’s the KW making the coolant dirty brown or oil?
    Thank You

    • Austin says:


      I think the K&W MIGHT have made a stain on your over flow bottle OR, more likely it was dirty coolant in the system that got flushed out during the 500 miles. As long as the coolant in the radiator is green, I would not be too worried about it. Yes, definitely top off the engine oil level and keep an eye on that on a daily basis. Oil could be getting in the coolant, but usually you see the opposite in these situations, coolant in the oil. If coolant in radiator is brown, go to your local oil change place and have them flush the cooling system with their flush machine.

      You might have an external engine oil leak or your engine could be consuming a small amount of oil due to internal wear. If you dont have any external leaks, you might want to try a can of Engine Restore oil additive the next time you change the oil. Also using thicker weight oil, like 20-50 Castrol can slow down oil consumption. Side effect can be lower fuel mileage, especially in wintery climates.

  86. Shannon says:

    Austin, I have read through multiple of your question and answer categories hoping to find a case similiar to mine… but still need help. I have a 96 Infinti I30. Replaced thermostat housing and thermostat, radiator cap, and tried stop leak according to bottle directions which for a 4 cyclinder like mine says to use half a bottle. Would like to try your method but it is winter time and cant do without coolant right now. Definetly an external leak… can see it dripping a steady stream from above the alternator…. even when the engine is not running! No coolant in the oil, no white smoke, but there is odor. Doesn’t appear to be the heater core as no “water” in my floorboard. Could it possible be when we replaced the thermostat and housing there is still air in the system and how do I bleed it? Faulty plastic parts or gasket? Water pump? Vacuum/pressure problem? Car runs fine…. other than it just pours out as fast as I can pour it in. Do I need to have a pressure test on an external leak? Thank you for your time and any help you can offer.

    • Austin says:

      Sounds like you probably have a heater hose leak or some other hopefully simple external coolant leak. If you can’t see the leak with your eyes, then yes get the cooling system pressure test to help you locate the leak source. DONT use any kind of sealer for this issue, just repair the leak.

  87. charlie says:

    help!!!! my son has a 2001 jeep classic. started overheating. changed the thermostat, still overheated. pulled water pump off to find the baffles were completely gone so no water moving. took radiator out and flushed by running water thru it until clear of rust. btw-radiator was replaced just 7 months earlier by the guy i bought the jeep from. how do i know you ask, well he is a golfing buddy and he told me before i even started talking about buying the jeep. and yes, we still golf together. lol!! anyway, after doing all that, the jeep ran fine for a while, then started overheating again, check engine ligth came on, little(very little) smoke out tail pipe, no water in oil. please help austin………..

    • Austin says:

      You have to start from scratch in these situations.

      1. Get a cooling system pressure test to determine if you have an internal or external coolant leak
      2. When does the engine overheat….freeway speeds usually means a problem with the radiator not circulating enough coolant or just low on coolant or an air pocket in the syste
      3. If the engine overheats at idle or slow speeds – usually indicates a problem with the electric radiator cooling fan or fan clutch if you dont have an electric fan

      Its not good that the water pump impeller was eaten up, that happens because of rust and electrolysis ……so what other internal engine parts are also damaged???

      The hardest part about these vehicles is getting all the air out of the radiator and cooling system, so make sure you have done that. An air pocket inside the system could cause your random overheating.

      I STILL think you have a restriction in your radiator if you had rust inside it when you flushed it….I know its only 7 months old, but in that 7 months it was bombarded with rust which stops up the bottom portion of the radiator. You might call a local radiator shop and see if they can “boil it out” for you, or just replace it again….once you have ruled out steps 1-3 above.

  88. Craig says:

    Hello there. I found your article with the alternative method of using KW Block seal intriguing to say the least. A year ago, my sister’s Jeep Cherokee was in need of a new radiator, which she mistakenly put off. I cut off her Heater Core that was chocked off to barely a drip, and JB welded a Rusted Freeze plug.

    This kept her going a year until an 8 inch gap blew in her rusted out Radiator. She drove the jeep to failure and either cracked her head or blew the head gasket – well at least that is what I think is most likely as water poured our from the back of the motor around the head gasket area near the freeze plug. I replaced her radiator, hoses, thermostat housing (it was leaking from a hairline crack) and her thermostat. Still the leak in the back persisted and started to literally pour. I went ahead and tried the last resort band aid – KW Block seal. I mixed it up well in the 3 qt suggestion, ran the car for 40 minutes and the leak stopped. I let the car sit 24 hours as stated, and was flushing the system when the problem area started to flow out freely again. Not to be defeated and with no time to pull the head, I went ahead and got another can of KW and decided to pour it directly into the radiator, chased by water of course.

    5 minutes later, the pouring hole stopped leaking and I let the car run 1 hour – and drove it 30 miles (such was my trust it would not leak) and ran the car for 1 hour and it never leaked.

    My question now is do you know if there is any benefit to letting the car air dry for say 2 days rather than the 1 specified? Also, is there any real inherent danger to allowing the sealer to remain in the cooking system for the “500” miles you stated? Do you know why leaving the sealer in produces better results? I had read somewhere that leaving it in or running the car longer than the 20 – 30 mins suggested, actually allows for more layers of “glass” to build up over the problem areas.

    Lastly, is there a safe time zone to pass where one can feel comfortable that the sealer has worked in a semi successful way?

    Thanks in advance

    • Austin says:

      All I can really add to this is please read my original article and my suggestions for how I personally have used the sealer in my shop for many years with great success…much more than as the can’s directions. Now if you have an obvious HOLE in something, the sealer is probably not going to be able to do anything for that. The sealer is copper flakes, than when hot melt basically. If you can see a hole or crack, then you will have to replace or repair what ever it is you see that is damaged. The sealer is meant to repair internal coolant leaks inside the engine, not external leaks.

  89. LAC in MISSOURI says:


  90. LAC in MISSOURI says:


    • Austin says:

      You replaced the radiator too?

      I would first,

      1. get a cooling system pressure test to determine if there is an external or internal coolant leak
      2. check to see that the cooling system has been properly bled and there is no air pockets in the system
      3. check to see that the electric cooling fan is working properly
      4. check to see that there is not a blockage in the cooling system, bad thermostat, kink in radiator hose, bad radiator cap

      I kinda think you probably have an air bubble in the system that needs to be bled out.

  91. Eric says:

    Thanks for the great info, Austin! I was wondering if you could help me. I have a 1993 Civic with the following issues: 1) Coolant needs to be topped off every few days, 2) visible exhaust unless radiator fan is on, 3) idling leaves big puddle under muffler, 4) hear water gurgling under the dash when engine is revved, 5) coughs when idling; paper held by exhaust gets sucked back in, 6) car is “bucking” on highway- feels like someone is kicking my seatback. I am considering K&B as instructed on your site. Do you think this is a good idea or do I need a pressure test first?

    • Austin says:

      Yes, please get a cooling system pressure test first before you do anything else. These vehicles did have a headgasket issue, and some of what you told me what lead me to think there COULD be an internal coolant problem…….but don’t jump to conclusions. Once you have ruled out an external coolant leak, like a radiator hose, radiator etc etc. and you are still having troubles, then yes, try the sealer as I describe. Your “bucking” on the highway could be an engine miss due to worn out spark plugs and wires, so double check them. Replace them if they have more than 50K miles……but repair the coolant leak first.

  92. Shellybean says:


    Am I sure glad that I happen to stmble on this very informative website;being a female, I think I know more about headgaskets than I could possibly ever dream, LOL.

    Anywho, here’s my dilemma:

    I have a 95 Olds, Achieva. Last Tuesday I went into one of the local Aamoco Transmission shops to get an oil change. From what I could tell, everything had went well, I had driven it as I always have. The very next day, as I was turning a corner, the car died on me. At first is started to do that putt, putting thing as I frantically pumped on the gas pedal, just hoping that I could get it as far to the curb and out of the middle of the road as it would go. Immediately after it cut off completely, I noticed a puff of white smoke (at least I think it was white?) that appeared to have come from the top of the dashboard. It did have a perculiar odor as well, I just couldn’t put my finger on it. As I tried to start the car back up again, it was a no-go. The lights did come on, and it did make that beeping ignition noise whenever I turned the key, but it just wouldn’t start up again. Does this sound like a blown head gasket?

    Oh yeah, with reading the many head gasket issues on this fabulous website, just let me add, that, yes I have noticed thick clouds of white smoke coming from the tailpipe, and it was always concering to me. Honestly, I just chalked it uo to it needing a new muffler & exhaust work. But is that only pre-warning indicating your head gasket is going bad before it actually dies? I mean it just seems so unfair, it was driving relatively fine before then, besides needing brakes all the way around….*sigh*

    I really can’t afford to pay a lot of money. I mean I can pay a few hundred, but really not more than that. Cars are such a darn headache!!!!! Especially really used ones like mine!

    • Austin says:

      Hearing about the white smoke out the tailpipe concerns me, so please have a mechanic do a cooling system pressure test to see if there is a coolant leak inside the engine….like from a headgasket leak. I kinda dont think you have that problem, but why the smoke? You probably have a fuel pump problem or a sensor problem like a crank shaft position sensor, their failures cause problems like you are having. I would suggest you get a professional diagnosis from the dealership, since this car is pretty tricky to work on and will require some special equipment and knowledge most shade tree mechanics might not be familiar with. Get the diagnosis then you can have any mechanic do the actual repair once you know what it is.

      If by chance there is a headgasket leak, use the sealer like I mentioned in my article before you sink any big money into the repair. Thanks for your kind words. ๐Ÿ™‚

  93. jim young says:

    Hi, see all this good information… Thank you for this.. Here’s my issue…
    2002 kia sportage, overheated because fan came off and my wife kept driving it. That was fixed, the head was taken off and milled, no cracks… Mechanic put the car back together, but now seems to think the block is cracked.. Antifreeze in oil… Will K&B work on this? The mechanic seems to think the crack might be to big? Car can run, but runs rough… might be tough to get car to drive 500 miles if the repair is not swift? Any suggestions? Step by step instructions? Will the engine get damaged running it with water in oil? Thanks for all this advice, you seem very knowledgeable.. Jim

    • Austin says:

      Yes, the K&W sealer would be a good candidate for this situation as well, but use the product as I describe within my original article not as the can directs. ๐Ÿ™

  94. Chuck says:

    I’ve read quite a few pages here and like what I’m hearing. I have 2 cars I have questions on. 1 is a 96 Chevy Lumina w/3.1 had a external leak last year and I thought it was the water pump – I replaced it and it still leaked. I thought it was the gasket so took it apart and redid it. It still leaked – saw the tan crap in the oil and decided it was the head gasket. I used the bars kind that you can use with anti- freeze and it did stop the external but I still loose coolant and it’s still making tan build up in the top of the valve cover. So yesterday I flushed and put in a can of K& W via the cans instruction. It’s been about 24 hours and I’m thinking of throwing in another can using your 500 mile method – what do you think?

    car 2 – 96 Grand Marquis that has a 5 inch crack in the front PLASTIC tube of the intake. I tried the bars anti-freeze sealant to get me home and have tried to epoxy the crack but it seems to seal under idle but when you increase the rpms a little – it springs a leak again. Do you think the K & W would seal this problem?

    PS love your comments and it seems your site has really helped a ton of folks – good job.

    • Austin says:

      Thanks for your comments Chuck. #1, get a cooling system pressure test to make darn sure you have an internal coolant leak and not an external leak like a radiator hose. If you are CERTAIN you have an internal leak, I would use the K&W sealer as I describe, not like the can suggests…just does not seem to work as well.

      #2, the K&W sealer is for use on internal metal parts not for plastic repair, so no it will not work on the plastic intake crack. JB Weld MIGHT work, but honestly I think you are just going to have to bite the bullet and replace the intake.

  95. andre says:

    hi austin

    i have a 1987 Toyota camery station wagon i just bought. its been about 3wk’s since i had it and it just started overheating when i went in to replace the thermostat i discovered it didn’t have one so i put the new one in then after that it ran cool for a few days then it started running hot again i’ve done all the tests to confirm if it’s a head gasket or not so now i’m going to try your method with the k&m product and see what happens, i have been all over the web looking for solutions and i’m glad to have run across your site, best information i have found yet.

    • Austin says:

      Its pretty common for people to remove the thermostat when the radiator is clogged up or restricted. I would bet you have a restriction in the bottom of the radiator and a replacement is needed.

  96. Steve says:

    Hi Austin,

    This is Steve, thanks for the advice, makes sense.
    For the last 2 weeks, the temp its getting, really hot even around town. It usually starts when I’m at a light and when I start moving, it goes down a little but after a few stops at lights it stays hot.
    When I pull over and check, I’m low on water in the radiator and the reservoir is boiling. I usually stop quick enough to see if its boiling over in the reservoir and most of the time is boiling but not overflowing.
    As you suggested, I too believe I need a new radiator.
    I guess my question is:
    If its the radiator not circulate the water on high or low speeds, should I expect to lose a lot of water?

    thanks again.

    • Austin says:

      First things first is to get a cooling system pressure test which will show you where a leak is if you have one, do that first.

      Next thing is to check the electric radiator cooling fans to make sure they are cycling on and off, especially important while car is at stop signs or slow speeds. Then once you have repaired or ruled out those items consider the radiator. if the radiator is original with 219,000 miles, I can be very confident that it needs replacement do to rust build up at the bottom. Now, if you have a coolant leak somewhere else like a hose, or if your cooling fans are not coming on…obviously replacing the radiator will not correct your overheating problem.

      If your radiator is leaking coolant or causing the engine to overheat and boil out coolant from the overflow bottle, then yes, the radiator could be the source of coolant loss, but if you skip the pressure test step I mentioned above….it will probably end up costing you more money in the long run. Dont skip that step, pressure test the cooling system first!

      Do NOT continue to drive with this engine overheating!

  97. Jessica says:

    So I have a 2000 GMC Jimmy that has a little over 180,000 miles on it. The other day I was driving on the freeway and all the sudden I had white smoke coming out of the engine area and the coolent gage started to sky rocket to over heating… the last car that I had that did this had a cracked head gaskit. So my guess is the same with this one… Also I have discovered that there is oil in my coolent tank… will the k&w engine blok work or is there another problem?

    • Austin says:

      I would suspect that you have an external coolant leak under the hood like a radiator hose or something like that that is spraying hot coolant on the engine to produce the steam you see. if the leak is not obvious with the hood up get your local auto mechanic to do a cooling system pressure test to find the leak.

      Its not to uncommon to see some oily residue inside the coolant plastic bottle. Having coolant inside your engine oil that looks like a chocolate milkshake is what you really dont want. Hold off on the sealer for now until you get this properly looked at, hopefully its nothing serious.

  98. mickey baumer says:

    Car was running fine (2000 Subaru Legacy) had belts & hoses changed. 1st, there was power steering prob. & mechanic said he had gotten air in the power steering fluid, but would work itself out. Didn’t. Took back & had them flush & clean system & now perfect BUT.. at the same time I said I was smelling antifreeze. NOt overheating, told that I have bad heater core & that’s why I smell it. Now notice antifreeze dripping from car, smell is from dripping on exhaust. Spent 2 hours w/new mechanic under car & cannot find leak. Original mechanic said he ‘was having trouble’ getting the air out of the radiator, but had fianlly gotten it all.
    Could he have done something? On a cold morning there is a good bit of steam coming out from under the hood but otherwise car runs VERY well & gauge stays just where is should (& always has been). Going back to garage to be re-checked to find leak.
    Any ideas?

    • Austin says:

      Wow, sounds like you might be better off with another mechanic ๐Ÿ™‚

      There are a few small heater hoses on these vehicles that can be difficult to install and maybe one of them is leaking? I am assuming the pressure test DOES show there is a coolant leak somewhere? I would assume there is a self induced leak somewhere and the pressure test should show them where it is.

      I doubt you have a headgasket leak all of a sudden. I would ask them to make sure they have bled the coolant system properly of air after they did the repair. Just like the air in the power steering system it can also happen with the cooling system.

      If these guys cant fix it for you today while you wait, you might offer to take it to the dealer and send these guys the repair bill.

  99. Steve says:

    Hi Austin,

    I have a 04 Civic with 219,000 miles and for some time now when I drive the car more than 30 mins or so on the highway, the car starts overheating. Recently, it seems to be overheating even when Im driving around town.

    1. loss of coolent
    2. reservoir bottle gets full with coolent and boils.
    3. Radiator bubbles.
    4. Replaced thermostat.
    5. Replaced radiator cap.
    6. No milky white liguid in the oil.
    7. No White smoke from the tail pipe.
    8. Do see gunk in my radiator.
    9. Flushed the radiator with flush kit.
    10. Replaced water pump a while ago but did not resolve issue.

    I have changed out the thermostat and the radiator cap.

    Talked to a Honda mechanic (A trusted mechanic) and he stated that its a head gasket leak. This is common on this year 02-05 Hondas with high milage. He suggested not to invest the $75 dollars to test it as he is 95% sure thats the issue.

    I’m ready to follow the directions with the K&W and wanted to get your opinion before I poor this into the radiator.


    • Austin says:


      How are you? I am BETTING that you have a stopped up radiator which will need to be replaced NOT flushed….which really does nothing at all. Yes, some Honda’s do have an issue with headgaskets and you MIGHT but from what you have told me I kinda doubt it and highly suspect a clogged up 219,000 radiator as the culprit. Its not a cheap guess, and its just my guess without looking at it personally but I would bet its a very good guess. Clogged up radiators show their symptoms mostly at higher speed because the coolant can not circulate throughout the system properly and boiling over in the plastic bottle is what will happen.

      Adding the sealer to a clogged radiator will do nothing for you either if the coolant can not circulate. Continuing to drive with the overheating issue will certainly increase your chances of getting a blown headgasket ๐Ÿ™‚ Now, after you install a new radiator you might still have to use the sealer if you are loosing coolant…..but I kinda doubt it. You can use an aftermarket radiator from a local auto parts store rather than a genuine Honda pricey radiator.

      Keep us posted as to what happens.

  100. Brandon says:

    Austin – I wanted to provide you a updated success story!

    My original message below and dated.

    Brandon says:
    June 20, 2011 at 10:54 am

    First I want to thank you in advance for any advice you may be able to provide me. I have a 1998 Range Rover HSE 4.6 that I purchased just about 3 months ago for $4500. As I am sure you have read this book before, I am having major overheating issues. It just recently began overheating with in 5 minutes of driving. I have of recently replaced thermostat, hoses, and flushed radiator. No success. I dropped it off at a local shop and was told to save my money and get out of the car. They told me that after running a pressure test and diag that they believe it is either a head gasket leak or cracked block.

    With that news I went to a local auto parts store and bought some โ€œsnake oilโ€ to attempt to band aid my broblem. I beleive I choose Bars Carbon fiber engine sealer. Per directed I poored container into radiator resevor (w/coolant) and ran heater at high. The car did NOT overheat on the way home. Fixed right? NOPE.

    Drove the care maybe 3 blocks up the street yesterday to the donut store and it overheated before I got there. No heater on. Last night I let the car idle in the driveway for an hour with the heater on and no signs of overheating.

    Any suggestions?

    Austin says:
    June 20, 2011 at 12:52 pm
    These vehicles are a great money pitโ€ฆโ€ฆโ€ฆBUT, there is probably hope for this issue, so lets not give up just yet. With any internal coolant leak I would EXPECT to see some of the following symptoms.

    1. Coolant loss, so you have to continually add coolant
    2. White smoke out the tailpipe
    3. A check engine light ON
    4. Running rough, engine missfire etc. due to coolant getting onto the spark plugs.

    Now, you did not mention any of those so I am going to ASSUME you do not have an internal leak, like a headgasket.

    I am HIGHLY suspect that you have a restriction inside the radiator though, just from what you told me so far, since the overheating usually takes place while the vehicle is motion.

    Its not easy to really see inside the radiator or to test itโ€ฆ.so you pretty much have to take a guess and replace it. If you have a radiator shop in your area, call them and see if they can โ€œboil outโ€ your current radiator for you. This can remove rust and calcium deposits that have built up at the bottom. Normally I would just tell you to replace it, but it is probably a pretty expensive special order radiator so boiling it out might be a better option for you.

    if you cant find a radiator shop, I would order an aftermarket radiator from your local auto supply and give it a shotโ€ฆ.its a gamble, but for a 13 year old vehicle, I would not be surprised if the radiator was clogged up. โ€œFlushingโ€ does pretty much nothing, and there is no chemical that really works either.

    Another thing that comes to mind, is a air pocket inside the cooling system that needs to be bled out. Some vehicles have a special coolant bleeder screw near the thermostat to remove the air in the system. Not sure if yours does or not. A call to the dealership might be helpful.

    If for some reason there really is a headgasket problem, K&W Block Sealer like I talked about in the article used as I direct, works for a last ditch effort.

    Running the heater acts like another smaller radiator inside your dashbord removing heat from the systemโ€ฆ.so if running the heater helpsโ€ฆmore suspicion about a clogged radiator arises.

    Keep in touch, thanks for the kind words.

    Brandon says:
    June 21, 2011 at 9:14 am
    Austin โ€“

    I hope this finds you well. Just to follow up on my โ€™98 RR HSE. I am unable to get the radiator boiled because it is plastic and alluminum. I back flushed the system multiple times last night and used a cleaner (flush). I know you said that the flushes are pointless but I assumed it would not hurt to try.

    I plan on adding the KW blocker tonight while I have all the Coolant out of the system.

    To answer a few questions that I left out.

    1. Coolant loss, so you have to continually add coolant (minimal)
    2. White smoke out the tailpipe (none)
    3. A check engine light ON (yes)
    4. Running rough, engine missfire etc. due to coolant getting onto the spark plugs. (seems to be running ok, when cool)

    However it does smell like anti-freeze and I do have boiling overflow.

    Thanks again.

    Austin says:
    June 21, 2011 at 5:08 pm
    If you have boiling over coolant in the bottleโ€ฆ.that would be more suspicion of a restriction in the radiator. If I were in your shoes and wanted to keep this vehicleโ€ฆ.I would gamble and replace the radiator. The block sealer is used to seal a leaking metal headgasket which I dont think you have. You probably just have an overheating issue, not a leak. The sealer will not help that.

    Your check engine light is probably not related to this issue.

    Recent update…..
    Since then I have replaced the source of the damage and seemed to have fixed the damaged block or gasket. I first added the KW and left it in for the recommended 500 miles. This almost immediatly solved the problem. However it would still run hot on the highway. I recently replaced the radiator as suggested. To date my Rover has not overheated again nor attempted to get hot. I now have approx. 3,500 miles on since the KW additive.

    Thank you for all your help and god bless.

  101. BobfromVirginia says:

    Hi Austin,

    I have a 98 ranger. Last year the radiator blew. I had it fixed, and then several months later the truck began running really rough. Burning 1 plug, blowing coil packs, etc. A trusted mechanic checked it out and said it has a bad head gasket. He said I had exhaust gasses going into the antifreeze, which makes sense given the blown radiator earlier. He gave me prices, etc. and I put the decision on hold. He said to keep the radiator cap loose for now (to avoid blowing the rad. again). His info makes sense. I bought a bottle of K & W nano and am ready to put it in today.

    Question is – will it work, given the exhaust going into the antifreeze? Just wanna check before I do this.



    • Austin says:

      Bob, yes try the sealer as I direct in my original article, you don’t have much to lose. I have had great success in similar situations as yours.

  102. Blake says:

    So far there has been no overheating and no coolant loss, i check my top hose and resevoir religiously now, and its still at the same level. The hose doesnt swell too much. The cap I have is the right psi. Thanks again for all your help Austin. I feel alot better about driving my car now.

  103. Blake says:

    Thank you for the advice Austin. Since I have replaced the radiator cap there has been no bubbling, coolant loss, or overheating. (note that it has only been two day so far.) could the radiator cap make that much of a difference? I’m still going to get the pressure test just in case. No electric fans. Just the one on the water pump and belt. Also, the top hose seems to have a bit more pressure even for being hot, perhaps the radiator is filled with too much sediment or any other possibilities? Thanks

    • Austin says:

      Well that might be great news, time will tell. if the radiator cap was faulty it will not allow enough pressure to build up inside the cooling system, which it needs to function properly. A radiator cap that is NOT releasing the proper amount of internal pressure will cause the upper radiator hose to swell….I have seen them twice the average size due to massive internal pressure. The radiator cap for each vehicle is different depending on how much pressure the manufacture wants to see. You should see a PSI number on the cap itself. I would check the coolant level inside the radiator in a few days, if its low get the pressure test. If its not low on coolant but still overheating….especially overheating at freeway speeds then I would be suspect of a clogged radiator. If no overheating or coolant loss, you fixed it!

  104. Blake says:

    Hey Austin. I own a 1988 Nissan 300zx, non turbo. It started to show signs of overheating, but nothing was presenting itself. I just figured an old car in Vegas heat running too long would be the problem. Then one day, it spit out all the coolant out of the resevoir and was steaming from the resevior and rad cap. So I changed the thermostat. But it’s still having problems with the radiator being low and the resevior bubbling and sometimes overflowing again. My oil isnt mixed with coolant nor does my exaust smell like coolant. I changed the cap yesterday since i discovered the old one’s rubber seal tore off. Thanks in advance

    • Austin says:

      Hey there Blake. First things first….get a cooling system pressure test to determine if there is a coolant leak or not, kinda sounds like there could be. If there are no coolant leaks I would check the radiator to see if it is clogged up at the bottom with rust which if it’s original I would be highly suspect that it is which is restricting flow of coolant. It that is the case, “flushing” will do nothing, a new radiator is the going to be the cure. I would also check to see if the electric cooling fans (if it has an electric radiator fan) is working properly. From what you have told me I do not suspect internal engine damage or a head gasket issue.

  105. Daniel says:

    Austin, I had my 2000 dodge Durango 4.7L engine replaced about four months ago. My coolant was boiling out of the res tank! I took it back to get it checked and my mechanic said it was because of my heater core. He advised me to make sure my coolant was topped off when ever I used it… Well it overheated and blew my heat sensors. Therefor voided my warrantee. My mechanic said nothing he could do. So now I’m stuck.

    I’ve block tested it.( no exhaust in the coolant) but the problem is still there. I’ve bypassed the heater core. Still there.

    You think that this may solve my problem? I just need a quick fix for now. I know in the long run, getting the head gasket is key. But I just threw $6000 at this truck and now I’m broke. Thank you for your time.

    • Austin says:

      I would get a cooling system pressure test FIRST to rule out any possible external coolant leak….and it should also confirm you have an internal coolant leak as well. You could have a restriction in your radiator that is/did cause the overheating issue and nothing is going to fix that until you get a new radiator.

      If the block test showed no hydrocarbons (exhaust gas) and the pressure test HOLDS pressure, I would be very suspect of a clogged radiator or some other coolant restriction (i.e. thermostat) that needs to be repaired. If you have an 11 year old radiator in this vehicle with more than 100K miles, I would not be surprised at all to see the bottom of the radiator full of rust/junk that can not be flushed out.

      If the upper radiator hose is MUCH hotter to your touch than the lower hose, I would try a new aftermarket radiator or see if your radiator can be “boiled out” at a radiator shop.

      I might also do a compression test on each cylinder to help me determine for sure if there is in fact internal engine damage, like a blown headgasket.

      IF you have ruled everything else out, yes try the K&W Block sealer additive the way I describe on the site, not as the directions on the can suggest….I hate to jump to conclusions that there is internal damage without doing the basics first.

      Keep us posted.

  106. Lois says:

    Hi Austin,

    It’s me again. I replaced my water pump, radiator, overflow unit, several radiator caps and several themostats. It was confirmed that my 2000 cadillac does have a cracked head. Now the question is, does K and W work well on aluminum heads or do I have to use a product called Blue Devil as suggested by Nappa? And also, at what point do I replace the thermostat and reconnect the heater core hose? Please help.

    Thank you very much in advance for your speedy reply!


    • Austin says:

      There have been many readers with similar vehicles and success stories with KW sealer and my intructions on how to use it. I would install thermostat now, heater hose connection can wait…you just won’t have heat this winter without it connected.

  107. Crystal says:

    Hello! I just tried this yesterday adding the K&W with nanotechnology. Still ran hot this morning, but not as quickly as it did before (yay!) Anyhoo, my question is do I put the thermostat back in now, or wait till after the 500 miles and I refill with antifreeze?

    Really praying this works, as it is almost winter here, and I cant afford to be without a car! ๐Ÿ™‚ Thanks for your help!

    99 Caddy Eldo – 89,000 miles

    • Austin says:

      You should put in a new thermostat now. Running hot could be due to not having the thermostat, a restriction in the radiator or a coolant leak somewhere external from the engine like a radiator hose. I would not be shocked if your radiator was restricted at the bottom where you can not see nor “flush”. You have to repair the cause of the overheating that caused the headgasket failure in the first place or it will just happen again.

  108. Anthony says:

    Good Evening, I wanted to post on your forum a big THANKS for this article. I thought my 1997 Honda Civic with 187k miles on it was going to be a paper weight after getting a diagnosis from my local shop of a leaking radiator and leaking head gasket (diagnosis came from failed Block test and UV dye test). I was looking at $1500+ in repairs. I told the mechanic to leave the car as is and I would pick it up. I was mulling over my options to sell for parts, etc when I stubled upon your website. I used the K&W NanoTechnology Permanent Head Gasket & Block Repair with your tips and my 1997 Honda Civic is no longer overheating. I was thiking it was not going to work at first because I was still overheating after 100 miles of driving with the K & N product in my cooling system. Around 125 miles of driving I noticed that my temperature gauge was staying still at the mid range, exactly where it should be! I will keep this product in the system until the 500 mile marker and maybe beyond. So far so good! Thanks again!

    • Austin says:

      That is awesome news, thanks for sharing it. I DO have to say that I would be highly suspect that you have a restriction in your radiator which probably caused the overheating and headgasket failure. I ONLY say this because of the age and mileage of the vehicle, I know nothing else about your vehicle. But, if the radiator is original to the vehicle I would bet that the bottom is full of rust and calcium deposits which restrict the flow of coolant. The sealer fixed the headgasket but not the cause of the overheating, you have to fix the cause or it will happen again. If radiator is original, replace it and the thermostat…..of course get a cooling system pressure test first to make sure you do not have any other coolant leaks, like a waterpump or heater hose etc. etc. Fingers crossed!

  109. Tom says:

    Which KW product is acually being used for these Kwik Fixes???

  110. Rita says:

    i just came from the shop they said i need a timing change in a water pump cause theres a hole in mine but they charging 509.00 is there any option i have

    • Austin says:

      I don’t think you have much of an option if your water pump is driven by the timing belt and there is a problem with either…I would replace them both at the same time which will save you a lot of money doing the job in combination.

  111. Matt says:

    I have a 2002 saturn SL1 w/ 125k miles. The other day I lost coolant suddenly BEFORE I overheated. Kept topping off with water to limp it to the garage. Hoped it was a hose, Mechanic said EITHER a blown head gasket or cracked head. He wanted another hour of labor for further diagnostics. (already paid him $50 to tell me my car was dead). I just limped it home with more water. I don’t know enough to know if he’s being straight with me or not, but in any case I don’t want to do a $1500 repair on a car with KBB of 2k or so. I also don’t want to sell it for scrap. Should I get a second opinion before I try K&W? Also, is the $60+ Blue devil sealer or other more expensive products really any better than cheaper things like K&W? Thanks!

    • Austin says:

      Definitely get a second opinion first! If the prognosis is an internal coolant leak then yes try the K&W sealer. Have not tried the others, but know KW works great in many cases.

  112. Steve says:

    Hi Austin, my wife drives a 2002 Subaru WRX which overheated due to running the car after a blown radiator. I replaced the radiator but car still overheats after around 5-10 min of driving. I have no coolant loss, no oil in coolant, and oil is clear, so I got it checked out by our local trusted mechanic. He first verified I had no air in the cooling system or external leaks, he then noted the upper hose was hotter than the lower hose after warm up (200F vs 120F) which he mentioned could be a problem with the thermostat (I thought this was normal?), then finally did a HC block test which turned yellow after 2 min at which point he says he can’t do anything more to help fix other than teardown ($4K+!). I’m about to try the new K&W Fiberlock HG & Block Repair which does not require the drain, flush, fill of the regular block sealer, but open to any ideas or suggestions. Thanks in advance!

    • Austin says:

      Sorry for my delay, was out of town. This sure does sound like a low coolant, or restriction of coolant flow more than an internal problem like a headgasket. I would TRIPLE check to make sure all air has been bled out of the system, and might also try changing the thermostat and see what happens. You can try the K&W as per my directions on my previous article, but from what you have told me I do not think you have that kind of issue. I would also make sure the electric cooling fans are working properly as well.

  113. Bruce C. says:

    Austin, Cooling fans working OK. Took out thermostat to be sure that was not the problem. I think the sending unit/guage is OK because when it gets hot, I can hear it boil. I will pressure check. Thanks.

    • Austin says:

      Make sure you reinstall a 195 degree thermostat. Do not drive without it.

    • Austin says:

      Also, if you have a radiator cap on the side of the radiator, remove it with the engine cold…start engine and let it burp out air as you add coolant. This could be a air pocket in the system.

  114. Bruce C. says:

    Austin, Thank you for the service you provide to those of us that cannot afford to pay a mechanic $75/hr to scratch his head and change parts until we are broke. I think it really is a service you provide. My car is a 98 Cad Deville. New radiator and water pump. Heats up even at an idle. Last mechanic said I could have a gasket leak between the piston and the water jacket causing blockage due to pressure entering the cooling system. If this is true, would the sealant method work? Seems to me the pressure would not allow the sealant to seep into the leak. What do you think? Thanks again.

    • Austin says:

      Thanks for the kind words Bruce. What I find is that 75% of the time a mechanic says there is a bad headgasket….they say that because they are LOST.

      If you were at my shop I would do the following.

      1. Pressure test the cooling system for a leak, this is done with a simple and inexpensive hand held air pump that attaches to the radiator.
      2. if no leaks, Check the cooling system for an air pocket that needs to be bled out.
      3. Check the electric cooling fans and make sure they are working properly
      4. Check the thermostat and make sure that coolant is flowing through the system properly and there are no restrictions.
      5. Check temperature sending unit and dash gauge and verify that the engine is actually overheating, not a gauge issue.

      Once those have been ruled out, and there is still a real problem, I would remove the spark plugs and do a compression test just to verify that the internal engine is not damaged.

      Since you did not mention any of the tell tale signs of an internal coolant leak, I can only assume that you have another issue. Engine miss fire, white smoke out tailpipe, continual coolant loss are common signs.

      The K&W sealer I mention does work great IF and only IF you have ruled out all other issues and a headgasket or internal coolant leak inside the engine are still suspected. It will not however fix any of the other issues I mentioned in the bullet points.

      Keep us posted.

  115. Lois says:

    Hi Austin,

    I have a 2000 cadillac deville. About two yrs ago it began to overheat, just out of nowhere. I got a “check coolant level” message on my indicator. I checked coolant level and poured a little more coolant in overflow, message went away. A couple of days later it did it again and then overheated. Took it to dealer and they replaced themostat. The next day after repair and driven only about 15 miles it overheated again, severely. The dealer wanted to tell me that I had a leak in my cylinder, unbelievable. Got several other opinions and was told that I needed a new radiator, water pump, another thermostat, overflow bottle and I replaced all; however, it still overheats. No oil and coolant mixture. Oil does run low, believed to be a seal or ring that needs to be replaced. Motor still sounds good, just recently started a somewhat rough idle when cold but dissipates within a few minutes of driving. Can drive on a highway trip for about 80 miles and does not overheat until I have to stop and go. No smoke from tail pipe and neither does it boil over but there are air bubbles in overflow/coolant. Am a single mom and can not afford extensive repair; warranty has been exhausted. Vehicle has less than 100,000 miles on it. Forgot to mention, sensors on motor were also changed. Thank you very much for your assistance. Lois

    • Austin says:

      Lois, if you are not experiencing any over heating issues during an 80 mile freeway drive, but do in stop and go traffic, I would suspect a bad electric cooling fan motor up near the radiator. Either the motor or a relay for the motor. This engine is delicate, do NOT let it overheat!!!!

      Get a cooling system pressure test to rule out any possible coolant leaks, then have the cooling fan motor operation checked out. Hopefully this is something simple.

  116. Haydee Gomez says:


    • Austin says:

      Well might be a good idea to change the oil after the gasket and spark plug wire change. The coolant…won’t hurt to change that if you can see stuff floating around in it.

      Remember you want to replace the spark plug grommets with the gasket, they should sell them as a kit with the gasket.

  117. Haydee Gomez says:


    • Austin says:

      I dont think you have an internal coolant leak….at least not that I can tell from what you told me. I would however get a cooling system pressure test just to make double sure. If there is oil on the spark plugs, I would expect to see blue smoke coming out of the tailpipe, but you say you dont have that. Are you sure the oil was inside the cylinder on the electrode of the plug and not on the outside of the plugs due to a valve cover leak. If you pull the plug wires off and there is oil on or in the plug wire, you have a valve cover leaking oil. I would also highly suspect the running problem and lack of power is due to oil getting inside the plug wires. If the wires are oily, replace the valve cover gasket and spark plug grommets, then replace the plugs and plug wires and see what happens.

      if you have oil on the INSIDE of the plugs, on the electrode, then I would get a compression test on this engine and see what the numbers say. If you have 1-2 cylinders that are lower than the rest, you might want to consider removing the cylinder head and get a valve job done along with replacing the headgasket and valve stem seals. This is going to be an expensive job.

  118. Haydee Gomez says:


  119. Kas says:

    note: temperature is shooting up while there is oil, water, and (so it appears) coolant. =(

  120. Kas says:

    Hey Austin… I like your site. It’s nice of you to help. I have a 99 Honda Civic (about 130,000 miles) that only recently started to overheat. I did a lot of driving one day and it started smoking (I never paid attention to the temperature until this). When I lifted the hood, it was all dry on water and oil. NOTHING there! I had someone put lots of water in there and some oil… it drove for a few minutes, then started overheating again. Took it to my mechanic overnight, he said I need a new radiator. He got me the radiator, gave me some Anti-freeze or coolant (don’t recall which) and then it started running fine again…. FOR ONLY A FEW WEEKS. In the last couple days, it started overheating again (as I’ve been minding the temperature now) and the engine light stays on. I checked this morning and saw that the water tank was empty… so I filled it. It still overheats, but at weird times… For example, I noticed that it overheats while in “Park.” I also noticed that the fan isn’t on while in park. But, to my surprise, if I turn the key to turn the cars electricity on without the engine, the fan turns on. Is that weird. How do I know whether the fan is working or not? This is supposed to be a new radiator, why am I having the same problems again? Any assistance would be greatly appreciated. At least I know, if it IS a head gasket issue, I can try your suggestion.

    • Austin says:

      First things first. Go back to the radiator mechanic and have him to a cooling system pressure test to determine if there is a leak somewhere. Make sure he does this, stand over him and watch him if you can. This is a small hand operated air pump that attaches to the radiator to pressurize the cooling system and make finding the leak easier. I would suspect you have a leak in the cooling system, or an air pocket in the system that needs to be bled out, or you have a cooling fan that is not working. the cooling fan sensor is located at the bottom of the radiator, so maybe its unplugged????

      When the engine is in the normal temperature range the cooling fan should be running up near the radiator. When you turn on the A/C the fan should also come on. You MIGHT have 2 electric fans hear the radiator. One for the radiator and one for the A/C condensor…..(the other radiator looking thing in front of the radiator)

      this is probably an easy fix, do not use the sealer…..yet.

  121. dec576 says:

    Very interesting info. My car is a 2001 Aztek and is getting hotter than normal but never gets to the point of lights coming on that it is over heating, runs to bottom of red area. While moving it is fine but gets warmer when stopped. Oil seems fine but coolant resevoir looks like someone put an air hose in it. I am adding some coolant but not a lot. Temp guage goes up then back down when warming up so I don’t think it is the thermostat. Would this be time for block seal or a something else? Any help appreciated, thanks.

    • Austin says:

      Get a cooling system pressure test first to determine if you have a coolant leak somewhere. I would be a little suspect of low coolant level or an electric cooling fan near the radiator that is not working properly. I dont think this is serious and would not recommend the sealer, I think you have a totally different problem.

  122. dakota sutherland says:

    hello , I have a 96 cavalier 2.2 the head was starting to seep ever so slightly . not even enough to leak off the block . never had any negative symptoms except a minor leak. it only leaked when engine is cold when it warms up it stops it was leaking on the back corner spark plug side right next to the head bolt. I put some k& w head gasket stop leak do you think itll last or will I have to replace gasket soon. any thoughts is appreciated.

    • Austin says:

      This is a coolant leak? Are you sure its from the cylinder head and not from the intake manifold or something higher up on the engine running down the head? Did you get a pressure test to confirm? The block sealer needs heat and compression to melt the copper flakes and seal the hole. I dont think it will do anything in your situation, buts its a cheap and easy guess and should not hurt anything else.

  123. Brandon says:

    Austin –

    I hope this finds you well. Just to follow up on my ’98 RR HSE. I am unable to get the radiator boiled because it is plastic and alluminum. I back flushed the system multiple times last night and used a cleaner (flush). I know you said that the flushes are pointless but I assumed it would not hurt to try.

    I plan on adding the KW blocker tonight while I have all the Coolant out of the system.

    To answer a few questions that I left out.

    1. Coolant loss, so you have to continually add coolant (minimal)
    2. White smoke out the tailpipe (none)
    3. A check engine light ON (yes)
    4. Running rough, engine missfire etc. due to coolant getting onto the spark plugs. (seems to be running ok, when cool)

    However it does smell like anti-freeze and I do have boiling overflow.

    Thanks again.

    • Austin says:

      If you have boiling over coolant in the bottle….that would be more suspicion of a restriction in the radiator. If I were in your shoes and wanted to keep this vehicle….I would gamble and replace the radiator. The block sealer is used to seal a leaking metal headgasket which I dont think you have. You probably just have an overheating issue, not a leak. The sealer will not help that.

      Your check engine light is probably not related to this issue.

  124. Brandon says:


    First I want to thank you in advance for any advice you may be able to provide me. I have a 1998 Range Rover HSE 4.6 that I purchased just about 3 months ago for $4500. As I am sure you have read this book before, I am having major overheating issues. It just recently began overheating with in 5 minutes of driving. I have of recently replaced thermostat, hoses, and flushed radiator. No success. I dropped it off at a local shop and was told to save my money and get out of the car. They told me that after running a pressure test and diag that they believe it is either a head gasket leak or cracked block.

    With that news I went to a local auto parts store and bought some “snake oil” to attempt to band aid my broblem. I beleive I choose Bars Carbon fiber engine sealer. Per directed I poored container into radiator resevor (w/coolant) and ran heater at high. The car did NOT overheat on the way home. Fixed right? NOPE.

    Drove the care maybe 3 blocks up the street yesterday to the donut store and it overheated before I got there. No heater on. Last night I let the car idle in the driveway for an hour with the heater on and no signs of overheating.

    Any suggestions?

    • Austin says:

      These vehicles are a great money pit………BUT, there is probably hope for this issue, so lets not give up just yet. With any internal coolant leak I would EXPECT to see some of the following symptoms.

      1. Coolant loss, so you have to continually add coolant
      2. White smoke out the tailpipe
      3. A check engine light ON
      4. Running rough, engine missfire etc. due to coolant getting onto the spark plugs.

      Now, you did not mention any of those so I am going to ASSUME you do not have an internal leak, like a headgasket.

      I am HIGHLY suspect that you have a restriction inside the radiator though, just from what you told me so far, since the overheating usually takes place while the vehicle is motion.

      Its not easy to really see inside the radiator or to test it….so you pretty much have to take a guess and replace it. If you have a radiator shop in your area, call them and see if they can “boil out” your current radiator for you. This can remove rust and calcium deposits that have built up at the bottom. Normally I would just tell you to replace it, but it is probably a pretty expensive special order radiator so boiling it out might be a better option for you.

      if you cant find a radiator shop, I would order an aftermarket radiator from your local auto supply and give it a shot….its a gamble, but for a 13 year old vehicle, I would not be surprised if the radiator was clogged up. “Flushing” does pretty much nothing, and there is no chemical that really works either.

      Another thing that comes to mind, is a air pocket inside the cooling system that needs to be bled out. Some vehicles have a special coolant bleeder screw near the thermostat to remove the air in the system. Not sure if yours does or not. A call to the dealership might be helpful.

      If for some reason there really is a headgasket problem, K&W Block Sealer like I talked about in the article used as I direct, works for a last ditch effort.

      Running the heater acts like another smaller radiator inside your dashbord removing heat from the system….so if running the heater helps…more suspicion about a clogged radiator arises.

      Keep in touch, thanks for the kind words.

  125. chris wilcox says:

    Thanks for all the help you provide. I just bought a bottle of k&w’s. Do I need to take out the thermostat? I just replaced it, and I don’t want to take it out, but I’m afraid that it will seal up the thermostat. Thanks.

    • Austin says:

      Leave thermostat in place and as is. Once you have cured the overheating problem might be a good idea to replace it when you flush out the sealer and go back to coolant water mix.

  126. Stacey says:

    I’m going to try this K&W stuff today. My only concern is driving the 500 miles. My car only overheats at high speeds on the freeway. So driving 500 miles around town will take me
    forever. Would letting the car sit in driveway and run be at all effective in compensating for part of that 500 miles? Everything on the car has been tested or replaced. Radiator, thermostat, hoses, and last advice I got was a head gasket starting to go bad. The only symptoms I have so far is the overheating on freeway and sluggish driving once in a while. My car is a 2000 Pontiac Grand Prix so I’m hoping this K&W stuff works before symptoms get any worse. Let me know about the 500 mile thing. I’m crossing my fingers this works!

    • Austin says:

      if the engine overheats only at freeway speeds I would suspect a restriction in the radiator (which will need replacing not flushing), or an air pocket in the cooling system that needs to be bled out, or something blocking air flow across the radiator or a restriction in the exhaust system like a catalytic converter that is bad and not allowing all the exhaust gases out of the engine. That is like trying to run a marathon with a clothes pin on your nose. I would have a QUALIFIED mechanic check those items first, I dont think you have a headgasket issue from what little you have told me.

  127. Levi says:

    Hello Austin, how is everything today. I last posted last year, my car (199 olds intrigue) is acting up still since it got here, was ok in the winter. Now it’s running hot and losing coolant when I start it and let it run for ten to fifteen minutes. I did get coolant leak test, replaced radiator, water pump, thermostat, and coolant reservoir cap. I am at a lost. I’m being told there is a head gasket problem but it only happens when the car is running for awhile. The engine light is on, possible tune-up, I’m told. Wondering if engine sealer will work. Please advise cause it’s a good car just can’t afford a new engine or another car now. Thanks for all of your help.

    • Austin says:

      I’m great, thanks for asking! You did not mention any of the tell tale signs of an internal coolant leak, like white smoke coming from the tailpipe, overheating, coolant in the oil etc. etc. Now, you did say something about the engine running bad and someone mentioning the need for a tune up….so did you get the spark plugs and other tune up parts replaced? They could be right in thinking a tune up is needed….and it could be the cause of the running bad issue and the check engine light, although you probably should have a mechanic read the computer codes to really see what is happening.

      The sealer works great, but its a last resort product, when you are absolutely sure you have an internal coolant leak like a headgasket and your only other option is a very expensive tear down….then use the sealer first and see what happens. In your case, if the pressure test is not showing any sign of a coolant leak…either internal to the engine or external like a radiator hose then I would not run out and use the sealer just yet. I would get someone with some mechanical skills to look this vehicle over for you, maybe do their own pressure test of the cooling system, remove a spark plug for a tune up inspection and kinda give this vehicle a good look over. I am NOT a big fan of this vehicle maintenance wise, so if you are presented with a big repair/maintenance bill I would think twice about putting any money into it with this many years and miles.

      If for some reason you decide to get another vehicle, stick with Japanese or Korean, Honda, Toyota, Kia, Hyundai… maintenance records and higher resell values.

  128. Diane says:


    Hello and thanks for all the advice you give out. What would be the first step to take in this situation? I have a 2000 Windstar. 160,000 miles. I smell burning coolant every time I drive it, especially when I get out of it after parking it. I have checked the reserve tank and there isn’t much fluid missing but it’s obvious someone thought there was a radiator leak because there is a copper metal-ish looking substance in the reserve tank that I know should only have water in. I also know that additives should be added directly into the radiator and not the extra/reserve tank. We just bought this van 6 weeks ago. Thanks in advance.

    • Austin says:

      I would get a cooling system pressure test before you do anything, this is more than likely an external coolant leak like from a radiator hose or radiator. The color in the overflow tank is probably from rust. Rust will form when there is a leak in the cooling system allowing air to oxidize metal parts inside the engine. Hopefully this is a simple fix. At that mileage and time interval I would bet all the water hoses are due for a change, and would not surprise me if the radiator was due for a change too, since there will be much more rust build up at the bottom of the radiator you can not see nor can you flush it out.

  129. Pete says:

    Thanks, I will try it today. The mechanic said the pressure was coming from one or two cylinders that were leaking and causing the compression in the coolant system.

  130. Pete says:

    I have a 1998 BMW 328, 140K miles no issues, until now. The pressure tank blew and I had it replaced only to be told that the head gasket was blown. Do you feel the sealant will work, this is not a $400-$500 fix, its $3K and KBB is $3500

  131. Guy says:

    I just replaced the head gasket,valve cover gasket, intake and exhaust man. gaskets. New thermostat. Engine runs fine. There is steam coming from exhaust and the coolant level drops. Can you help.

    • Austin says:

      Get a cooling system pressure test to see if you have an internal coolant leak. A cylinder head could be warped or cracked or there could be coolant residue in the exhaust system that needs time to burn out.

  132. Jason says:

    Hi Austin, I’ve got a 92 cadillac with a 4.9. There is antifreeze in the oil and it smokes. Does this stuff seal cracked heads if that is the cause? Of course it is the back head that has the problem.

    • Austin says:

      Jason, if you got a cooling system pressure test and have determined that you do have an internal coolant leak….yes, I would definitely try the sealer as I describe in my article, not as the can instructions. Keep me posted.

  133. marlene says:

    my sons 1996 saturn has been loosing oil. then last weekend it stopped running. we took it to the mechanic and they replaced a fan belt. it drove for 3 miles with “grey” smoke pouring out the exhaust and then would not start again. please help

  134. dncholas says:

    I’m going to try this method this week per your directions and I already know that most sealing additives need more than the manufacturer’s directions of 20-30 minutes and fixed. I can already believe that your method would do a much better job. I’m sure my head gasket has a leak but not bad yet and only really gets hot when I really gun the car on the highway so the probability of this fixing is even higher. Local driving runs fine but does go through coolant. Also this is a modified AWD turbo with a lot of boost (lowered by manual controller) and not having too many probs but do not want to take this engine apart as good as it is and small as the leak. I will report back later in the week the results. Thanks in advance and if works like you say then I’ll donate to your website. Promise ๐Ÿ™‚

    • Austin says:

      Great, keep me posted. I do not accept donations, just the fact that I was able to help you is all I ask. Of course you can tell your friends about me and my site. ๐Ÿ™‚

  135. Michael says:

    Speculating on an issue recently discovered from my 75GMC sprint. Have discovered from trying to research overheating issue that the pass side is leaking antifreeze at a reasonable drip. I have seen it is coming down from top side of head near intake manifold and possibly from bottom of same head or maybe just pooling point as it drips off. Should I try an additive on this? Should I just bite the bullet and remove the head (novice mechanic) or take it to my mechanic?

    • Austin says:

      I would get a cooling system pressure test first and see where the leak is coming from. Could be something simple like a heater hose leak. Save the sealer for a last ditch resort to repair a known headgasket leak.

  136. Angelique says:

    I know that I don’t have an external leak. I don’t loose coolant. I have NOT added coolant since the overheating began. That was about a month ago. I do not have a direct access cap to radiator. In my vehicle the cap is on the overflow which drains directly into the top of the radiator. The fan comes on. If I put water into the top of the radiator it does flow out the bottom. I had orange coolant, and it was filthy. I flushed the system today. After 5 hours of flushing I am still getting dark orange coloration. I can’t imagine that this is coolant still, I am guessing rust???? It is a 13 year old vehicle and I know water plus metal equals rust. I have one last question, I have not had the pressure test done. Two mechanics, one a local mechanic and one from a major repair shop, both have said that I have large amounts of hydrocarbons emitting from cooling system, and that is a classic sign of headgasket failure. If the headgasket isn’t the culprit, then how did the hydrocarbons get into the system.

    • Austin says:

      I can only suggest what I have already suggested you do. If you have not added coolant….then you do not have a headgasket leak. there could be some hydrocarbon deposits inside the radiator from other sources like engine oil…and maybe even rust, which is why your coolant is orange. You most likely need a new radiator and thermostat like I mentioned last time.

  137. Angelique says:

    Hi Austin, I emaile you awhile back. I have a Ford Expedition 1998 4×4 with a blown head gasket. It has been confirmed, I failed the block test miserably at two different mechanics. Initially I only had periodic overheating with pressure in the coolant system and hydrocarbons emitting from the coolant system. Now I have some oil in the water and the truck is overheating often. I can only go a few miles and it overheats instantly with no warning. I loose very little fluid, but definitely head gasket issue. I am going to try the product tomorrow and see what happens. My heater has stopped working too. I do not smell antifreeze and I am not loosing antifreeze very fast so I don’t think heater core is leaking. When I say heater doesn’t work I really mean NO hot or warm air emits from it. Friday I am going to drain the radiator and flush the system. Then I will add the product and drive around. I have to be cautious of overheating, any suggestions as I do not want to do more damage. I am hoping this works cause I am a mom of 4 little (2 years of age and under) children, and absolutely do not have the money for head gasket repair.

    • Austin says:

      Did the mechanic do a cooling system pressure test to see if there are any external and internal coolant leaks? To me, this sounds like you have a coolant flow restriction, either from a clogged up radiator or a faulty thermostat, or low coolant level in the radiator. If the heater is not getting hot, feel the two heater hoses under the hood on the passenger side when the engine is hot….are the two hoses hot as well?

      Are both the upper and lower radiator hoses hot when the engine is hot, they should be. I would not be surprised at all to see this radiator clogged up and needing replacement….flushing will NOT do much of anything except remove some rusty water, it will not unclog a radiator.

      If you were at my shop I would do the following.

      1. Pressure test cooling system to rule out/in an internal or external coolant leak
      2. If there is an external leak like from a hose, repair it and re-pressure test
      3. If there is an internal leak, check other cooling system items for overheating issues before repairing internal leak (engine had to overheat to begin with to damage headgasket)
      4. Check radiator for restriction
      5. Check thermostat operation
      6. Check air flow across radiator and fan clutch
      7. Test radiator cap

      Once I have done those steps I should be able to determine what caused the overheating and the headgasket failure so I can repair it so it does not overheat again causing another headgasket failure. I can then try the K&W Engine Block Sealer additive as per my directions on my original article…..not directions on can.

      I think you need to find another mechanic, someone who does not jump to conclusions and is willing to properly diagnose the problem.

  138. bruce says:

    Well I have been reading all these comments and NOBODY says anything about the oil……i know you empty the radiator and coolant/water and take off the thermostat but what about the milky oil… you need to change the oil before you put in K&W or leave it in……if your oil and coolant/water is mixing, wont the K&W mix with that milky oil… the oil suppose to be empty or new or milky or what?……cuz as soon as i mix the K&W its gonna mix with the milky stuff or with the brand new oil…..correct?

    • Austin says:

      Bruce, you bring up a great point. I look at it like this. If the oil is contaminated with coolant to the point where it looks like a chocolate milkshake, then yes change the oil before you drive the vehicle 500 miles like I suggest in my original article to do. If the oil looks fairly normal, and still feels like oil…then I would wait until you complete the 500 miles and change the oil when you drain out the sealer water mix. BTW. I do not recommend you take out the thermostat. The sealer works with heat and compression and should not affect your engine oil…..although it will contaminate it along with coolant/water until the leak is repaired.

  139. Michael Clancey says:

    Yes the heads went to a machine shop and were surfaced and valves ground, etc. I actually did not perform a coolant pressure test since I can see the steam coming out of the tailpipe. I guess it would not kill me to turn the engine and retorque the head bolts and intake bolts. It beats junking the car and I can do that easily enough. Thanks very much for your help. I will keep you posted.

  140. Michael Clancey says:

    After a complete cylinder head refurbish/head gasket replacement in my 1996 Monte Carlo 3.1, to my horror there is still white smoke coming out of the tailpipe. I used highest quality Felpro gaskets and have done many top end overhauls in the past. Apparently I must have missed a cracked block somewhere upon inspection. On the bright side, there is no more overheating at all and minimal pressure build up. Unfortunately there is a pretty good miss in cylinder #3 and the power sucks after it warms up.

    I have had pretty good luck with K&W in the past, but so far this product has not had the desired effect in this vehicle. I started with the manufacturer’s instructions (with the exception of letting the vehicle idle for about 5 hours before draining it and letting it cure). After I stumbled onto this site, I decided to treat again and leave it in for the longer period of time suggested. The problem I am finding is that the car seems to run worse and smoke worse after driving it for awhile. I have therefore been driving it in town for just a few miles and then shutting it down with the hope that several such cycles might build enough product up to seal up the block.

    I am wondering if there are any additional considerations for block sealing as opposed to head gasket problems that might be helpful? Perhaps additional product or removing the affected spark plug? I am already out the cost of head rebuilding and parts (and my time) but I know the head gaskets are now good so I feel like I at least have an advantage in that regard. My thought process is to give K&W a good try with this method and maybe follow it up with trying another similar product that requires a clean cooling system without antifreeze contamination. If that fails I intend to maybe try a product that mixes with ethylene glycol. Bottom line is that in my eyes I have everything to gain and really nothing to lose if I can avoid junking the car. Any suggestions would be most appreciated.

    • Austin says:

      Did you have the cylinder heads resurfaced at a machine shop? The heads will warp, and cause a gap in between the headgasket and the heads and block. You probably dont have a crack in the block, but could have a warped head or a crack in the head. The proper way to replace the head gasket is to take the cylinder heads to a machine shop and get a valve job done, magnaflux the heads for cracks and resurface the heads and grind all valves and replace valve seals. This way you have basically rebuilt the top end of the engine.

      If you did that and you still fail a coolant pressure test…..which I hope you have done, then I would triple check your head installation, retorque all headbolts and intake bolts etc. I would also pull out all spark plugs and check for signs of coolant in the cylinder, and do a compression test while the plugs are out.

      Once you have done that, drain out all coolant, install the can of K&W block sealer and use the directions I give on my original article page not the directions on the can. I would take a few gallons of water with me, and pack a lunch and set out for a 100 mile drive around my town on a nice day, but staying close to home just encase you need to make a pit stop. The sealer will work the same for a block crack or head crack, but if you have a head that is not torqued down properly….you are spinning your wheels.

  141. Alan says:

    I have 1988 Chrysler LeBaron that started leaking water and running ruff. I changed plugs, cap , wires and put some stop leak in the radiator. Ran it for a day, radiator continued to leak and it was still running ruff. No 3 cylinder was dead. Replace the radiator and hoses and noticed car ran perfectly until the thermostat opened up introducing water to the head. I figured I had a blown head gasket. Could be a warped head or cracked block but I went with the gasket angle. Decided I would try to tackle taking the head off and fix it myself. Got about 5 hours into it and realized I was over my head. If it did not have a turbo, I think I could of done it. I put it all back together and once again ran perfectly till water got into the head. Anyway, I was quoted $2000 + to be fixed by a mechanic, the car is not worth that. Last try, I put K&w stop leak yesterday and suddenly the leak appears to have stopped and the car is running fine. I followed your directions and will wait 500 mile to change water to coolant. I will let you know the outcome. Thanks for the info!!!!

  142. Angelique says:

    One more thing to add to the above. My heater doesn’t work at all, and it use work some. It hasn’t gotten hot hot in a LONG time. Now it doesn’t work at all. I don’t know if that is an important piece of information or not. Like I said otherwise vehicle starts right up, idles smooth, accelerates smooth, just passed smog.

    • Austin says:

      Yep, that is normal IF there is not enough coolant in the radiator to heat up. Your heater needs hot coolant to get hot inside the vehicle. Not enough hot coolant….no heater. One more reason to believe you either have a coolant leak and there is not enough coolant inside the radiator or the coolant can not flow properly inside the cooling system either a restricted radiator or a faulty thermostat.

  143. Angelique says:

    I have a question. I have a 1998 Ford Expedition. Runs great, its only symptoms are that it overhears going up hill and in stop go city traffic (I live outside Los Angeles so plenty of traffic, and I live up in the mountains so lots of hills). It overheats rapidly. It goes from 40% on the temp guage to 100% in an instant. The engine light is on. I took it to local mechanic. He opened up the water reservoire and it hissed at him. He used the smog test wand and measured hydrocarbons coming out of the reservoire. I do not have water in the oil, I do not have oil in the water, I do not blow white smoke, I do not smell the sweet aroma of coolent. The mechanic told me that it is with out a doubt a cracked head gasket. So would the KW sealent work, is it worth a shot. I don’t have the money to repair the vehicle at this time.

    • Austin says:

      So did the mechanic perform a cooling system pressure test, as I preach about? That test is the very first thing anyone should do in this situation. To me, it sounds like you either have a low coolant issue, due to a leak somewhere, or you have a restriction in the cooling system somewhere….probably in the radiator.

      1. Check the water inside the radiator, if its low, get a pressure test to find the leak and repair it.
      2. If the radiator is full of water, then check the flow of water in the radiator. You can sometimes take your hand and feel the upper radiator hose then the lower hose when the engine is at normal running temperature, and they should be fairly close to the same temperature. One hose should not be a lot hotter/colder than the other. If so, there is a problem inside the radiator and its time to replace it.
      3. If the radiator is full of water, and you cant feel a major difference in the radiator, you might want to replace the thermostat and see what happens.

      I dont think you have a headgasket issue, but I do know you need to find another mechanic, a real mechanic to properly check this out for you.

  144. anglia says:

    on a 06 kia spectra, coolant in the oil, this means a cracked head right? im going to use the k&w on it but it says to flush well befor using. i bought a flush kit and it has a siagram on the back regarding the heater hoses. this does not look like mine. the two hoses come from right beside each oter on the fire wall and go right beside each other on the motor. how do i know which is the inlet hose?

    • Austin says:

      Get a cooling system pressure test FIRST and make sure you do in deed have an internal coolant leak….which if you just have a little coolant residue inside the oil you may or may not have a problem. You might have a little condensation which can make the inside of the oil filler cap appear chocolate milky looking…that could be normal depending on how much condensation you have. If you fail the pressure test, then yes try the sealer as I directed in my article. No need to use a flush kit.

  145. Paul says:

    1984 Toyota SR5 22R 4 cyl engine; On my engine the timing chain had worn a hole on the plate that separates it from the water pump. Needs to be replaced to fix it.

  146. kris says:

    i have a dumb question i used k&w block seal on my dakota i did it to the manufacture instructions. i am in the 24 hour waiting time. should i buy another bottle and do as you directed .

    another thing will i need to do a tune up to fix the “stall” in the motor and how long after i run the block seal should i change my oil to get rid of the milky texture?

    thanks kris

    • Austin says:

      The stall issue could be due to lack of compression from the headgasket failure assuming you did do a cooling system pressure test first as I suggest heavily. My way vs manufacturer seems to work best but make sure you do have an internal coolant leak first. Change the oil now if there is obvious coolant in it.

  147. Cricket says:

    My F350 diesel is in the shop as with an antifreeze leak. They are doing a cooling system pressure test. Will K & W work on a diesel engine?

    • Austin says:

      I am not a diesel mechanic so I have no first hand personal experience but I think the new “nano technology” version of the sealer states its for diesel and gasoline.

      I took this from their website, from the older version of the product

      “Forms a permanent molecular bond that’s as strong as steel. Seals cracks & holes in cast iron & aluminum engine blocks, head gaskets, freeze plugs, & copper, aluminum & bi-material radiators & heater cores. Tested by an Independent test lab. Rated No.1 “

  148. Kurt Bresler says:

    I have a 1984 Toyota SR5 22R 4 cyl engine. the water was overheating and I found water in the oil. I cleaned cooling system with prestone in the yellow bottle, flushed radiator with clean water and tried the Bars leaks rabbit pellets twice, no fix, I then ran the
    __ blue bottle of rad cleaner, flushed out 5 times and put in the K&W stuff that looks like rusty colored wet dust, then I ran my car up to pick up my wife about 10 miles. Starting home my engine started missing and acting up, sputtering and dying several times, When I got it running to get home it may have been running on one or two cylinders at the most. I am thinking that I have blown it up completely. I heard noises coming from the engine so I am thinking that the coolant got into the cylinders and messed up the rings or valves or something Can anyone help me

    • Austin says:

      Will it start and run OK now….no noises or missing? If so, I would highly suspect a restriction in the radiator and a new radiator is in order. If you were at my shop I would do the following.

      1. Pressure test cooling system for internal and external leaks, do NOT skip this simple test!!
      2. Check radiator for restriction, feel upper and lower radiator hoses to make sure there is not a huge temperature variation.
      3. Compression test engine to make sure there is not internal wear, although if you have a blown head gasket you will have weak compression on a few cylinders

      If is starts and misses and sounds bad, then you need to talk with your mechanic and have him do the steps above and give you an estimate of what kind of money you are going to spend and if its worth putting that kind of money into this vehicle. You can still try the sealer, but I won’t hold my breathe at this point, but you never know and its a cheap guess.

      Adding the K&W sealer should repair the blown headgasket issue but it will NOT solve a problem with the radiator. So, you have to repair the cause of the head gasket failure, in your case most likely a clogged radiator before you can repair the damage caused by the overheating or you will just be repeating the overheating cycle over and over again.

      On another note, these little engines are tough and dependable. Removing the cylinder head should cost you about $150, having a machine shop perform a valve job on the head another $125, reinstall the head another $150 and another $100 in parts. For not a whole bunch of money you can basically rebuilt the top half of this motor which will correctly repair the head gasket issue as well as rebuild the cylinder head. That is the correct way to solve a blown head gasket. Don’t forget you ALSO will need a new radiator, coolant and should always install a new thermostat as well. Another $300 parts and labor +-

  149. roberto says:

    I have a 2001 BMW 330xi. 140,000 miles and the coolant has oil in it. No coolant in the oil. Car never overheated to my knowlege. Should I try KW before I tear it down for a head gasket?

    Is there a solvent or something to clean the oil from the cooling system prior to adding the KW?


    • Austin says:

      Do NOTHING until you get a cooling system pressure test to confirm you have an internal coolant leak… have not convinced me that you do. Take this sealer seriously, its not something you just use just because you want to try it out. Its a last ditch effort before spending $1500 on a head gasket replacement. IF, and only IF you have gotten the pressure test and are sure you have an internal coolant leak….then by all means use the sealer and see what happens, you got nothing to lose.

  150. Derrick says:

    Hi Austin,
    So… I have the car running again and I ran the car for at least 30 minutes (15 minutes idle/15 minutes driving) and no overheating. I’m hoping my overheating problems are fixed but here’s the thing that bothers me. the top hose is still quite hot and the bottom hose is luke warm… could this be okay? after running for at least 30 minutes, i would have expected the car to overheat if it wasn’t… let me know your thoughts.

    thanks again.

  151. Derrick says:

    hey austin,
    well for sure if i fill some fluid from the top of the radiator cap, it should go first to the lower hose rather than the top hose right? ๐Ÿ˜› forgive the stupidness

  152. Derrick says:

    Hey Austin,
    Also to double check… i tried to use a shopvac and attach it to the bottom drain of the radiator (where the pipe would normally connect to the engine to feed cold fluid) to suck out anything that might be blocking it… it definitely sounded like it couldn’t suck any air in when i attached it to it… it should be able to suck in air easily right? if the radiator cap is off?

  153. Derrick says:

    Hi Austin,
    You are correct :(. the Radiator is definitely blocked.. ARGHHH! here’s how i checked… i took off the lower hose after draining the K&W sealer fluid and started trying to fill the radiator from the radiator cap… the top hose started leaking water out and the bottom hose only dripped some water… ughhh!

    i am pretty sure the K&W sealer blocked it :(. my car never overheated before i started using the sealer so my guess is that the sealer started building up in the radiator and then hardening when the radiator cooled down when the car was off… did you ever have problems like that? now i gotta go get a new radiator :/… any suggestions on where to get a good one? i saw some for less than $100 online.. 1995 toyota tacoma 2.4L.

    • Austin says:

      The sealer did not clog it, it only hardens when combustion gas and compression are present. The radiator is clogged with rust and calcium deposits. $100 is cheap :). Replace the thermostat at the same time

  154. Todd says:

    Does the K&W “Nanotechnology” Head Gasket and Block Repair require driving a minimum of 500 miles?



  155. Derrick says:

    Hi Austin,
    appreciate all the input. here’s what i think is the situation at this point.

    1. air pocket around thermostat leading to the thermostat not opening causing no coolant flow
    2. thermostat is bad (i didn’t think it was because i did a test on it and it did open)
    3. lower coolant hose is pinching when i rev the engine (need to check for this)
    4. block in radiator preventing coolant flow

    in your experience, would you say then when the car is in operating temperature, the upper radiator hose should be slightly hotter than the lower radiator hose? or would you say the lower radiator hose would still be a good amount cooler?

    • Austin says:

      What you want to check is, is there a vast difference between the upper and lower radiator hoses. If so, you have a restriction in the radiator as long as the radiator is full of water. Yes, an air pocket could also cause your troubles as well. Most of the time you can remove the radiator cap (engine cold) and slowly add water until the thermostat opens. Some cars have a coolant bleeder screw near the thermostat.

  156. Derrick says:

    Hi Austin,
    Before I did this K&W process, I didn’t have this problem before with overheating, especially on freeway driving. the only time it slightly overheated was when i was at a stoplight. when i started moving, the temp went down. i opened the radiator cap after that and it was because my coolant level was low. could it really be the radiator?

    • Austin says:

      I would get a cooling system pressure test to rule out a coolant leak then have the radiator checked for a restriction. Also make sure the electric cooling fan motor is working…if you have one. I am not convinced you have a headgasket or internal coolant leak at this point

  157. Derrick says:

    hi austin,
    so i’m using the K&W sealer and flushed flushed flushed, then put distilled water and sealer into the radiator. i did NOT take out the thermostat. but i DID check to make sure that the thermostat worked and that the jiggle valve was pointing at 12 o clock. i start the car and let the car idle for about half an hour with no overheating. next morning, i check the coolant level and it’s fine and i go to work (about 7 miles away) with no overheat problems. 9 hours later i check my “coolant” levels and they are fine, i go to dinner from work (10 miles away). near the last 10th mile, i notice that the temp gauge starts to go towards the hot end. i reach my destination with the temp meter at about 75% towards the red and park the car. i thought that maybe it was because the car was driving in city roads. 2 hours later i start driving home. i get on the freeway and about 10 miles in, the car starts going towards the red (temperature about 75% up). i pull over to the side of the freeway and wait… i feel the top radiator hose and it’s hot. The bottom coolant hose is barely warm. i wait 10 minutes and check and the temperature is back to “operating temperature” (temperature about 40% up). i drive about 4 miles and the temperature goes up again to about 75%. i pull over again and wait to cool. drive again and go 3 miles home and about the last quarter mile the car is again at 75%.

    feels like the thermostat isn’t really opening since the bottom hose is luke warm. top hose is scalding hot! reason why i was using the k&w sealer was because i had white smoke blowing out of my tailpipe (which seems to have stopped), a milky cover on my oil cap, and some bubbling in the overflow reservoir, and coolant that wouldn’t be sucked back into the main radiator from the overflow reservoir (which seems to be resolved because when the car started overheating the fluid was going to the overflow bottle, then when it cooled, it went back to the normal amount) i had a theory that there might be an air pocket next to the thermostat, but i thought that the jiggle valve was suppose to resolve that. any help would be appreciated… sorry for the long winded text but i figured i’d give you as much info as possible.

    • Austin says:

      To me, from what you told me I would be suspect of a restriction in the radiator. A new radiator and a new thermostat might be in order. A radiator restriction usually shows up when driving at freeway speeds more so than city driving. Boiling over in the overflow would also be a good indication that the coolant in the system is not circulating properly. If this vehicle is older than 8 years or has more than 80k miles, I would not be too surprised to see a restriction in the bottom of the radiator.

  158. YOLANDA says:

    My 1999 Pontiac Montana has a blown head gasket. Will K&W sealant help it for another month until I can get another car. Thanks in advance.

  159. RobS says:

    I used the treatment as perscribed by the manufacturer. It seems to be better, but still having issues. I noticed at the part store today a new “nano” formula. Have you had any experience with it? Is it worth the additional money? Should I leave it in for 500 miles as well? Can I do it over top the old stuff? Sorry for all the questions, but its a great car (98 Continental) and I’d like to keep it.

  160. Rob says:

    Austin, Came across this thread and your site last November.
    Our 2002 Pt Cruiser was “boiling over” on a regular basis after having replaced the entire cooling system, minus the radiator. The timing belt and water pump had been replaced 6,000 miles earlier. Head gasket and head resurfaced 48,000 miles before also. On Nov 20th I used the K & M block sealant per YOUR complete instructons. I have put 4,800 miles on now and have NOT changed back to antifreeze. At 140,000…..she runs better than she did when we bought her at 13,000 !!!!!
    My mechanic ,and myself, can’t believe it and he’s asked me to

    THANK YOU for him and me !


    • Austin says:

      Awesome, thanks for the update. Although, I would advise you go back to the proper coolant/water mix for freeze and overheating protection. Time to drain out the sealer, sounds like its done its job.

  161. al says:

    working like a dream so far for me,its only been 2 weeks,im keeping my fingers crossed..dont use it by the manufactors directions,it didnt work for me,run it in you radiator for a while before draining it out,its been over 300 miles and im still not running hot anymore. before i couldnt drive no more than 20 minutes before boiling over in my resevior tank…..

  162. Joy says:

    You’ve mentioned “I have had great success using the K&W block sealer as I mentioned, but not as the manufacturer suggests.”

    You poured the pure K&W sealer directly into a drained radiator? Not per Manufacturer instruction of mixing K&W with 4 quarts of water and subsequently pouring this mixture into radiator? Please confirm. Thanks!

  163. Charlie says:

    Austin – I’ve done the temp. differential check and it’s within 15 degrees…I am beginning to suspect that maybe some threads in the block have been pulled a (small) bit. I will do the K&W thing, properly, and keep you posted.

    I appreciate your time and sound advice. This is very hard to come by anymore as I’m sure you know. Thanks!

  164. Charlie says:

    Austin – One of the first things I did was check for exhaust gasses in the cooling system and I am sure a head gasket is bad…

    • Austin says:

      What we really need to do is figure out WHY you have a blown head gasket. The engine most likely overheated, but how? If you dont have any external coolant leaks, I would be suspect of a bad radiator. Let the engine warm up to normal operating temp then run your hand down the radiator starting from top to bottom (you can also feel top and bottom radiator hoses).

      There should be a SLIGHT temp difference from top to bottom. If there is a massive difference, you probably have a restriction in the radiator. If you do get the sealer to repair the head gasket, the engine will likely overheat again with that radiator. Make sense?

      Other Northstar owners have reported back to me success with the sealer, so it should work for you as well.

  165. Charlie says:

    I have a 1998 Cadillac Seville STS/Norhtstar 4.6 with a small head gasket leak into the cooling system except under load (long, steep grades) in which case the pressure that builds up blows the coolant out of the surge tank, overheating the engine. If I use the stuff as directed (flush/idle for 30 minutes/air dry), the pressure will be OK. If I drive for 500 miles AND pull any grades will the K&W seal enough to stop the purging of the cooling system? Again, relatively flat roads and the pressure is OK but any load and it purges due to excessive pressure. Any suggestions?

    • Austin says:

      Are you sure you do not have a restriction in the radiator??? Kinda sounds like you have a restriction in the coolant circulation rather than a headgasket problem. Rule that out first.

  166. Greg says:

    My daughter has a 99 Neon that has been leaking a steady amount of oil. It appears to be coming from somewhere in the back of the block. She tells me that at random times, more so in the summer, there is smoke from the engine compartment and she looses acceleration. I have never witnessed, or been able to reproduce, this but I have had to refill the coolant & oil more than I normally would. There hasn’t been any smoke out of the tail pipe and the oil always looks normal. The garage said it was a blown rear hd gskt. I didn’t get the cool press test yet. Is it possible to have a bad hd gskt w/o all of those other signs of trouble?

    • Austin says:

      It could be leaking oil from the cylinder head, these Neons had an issue with headgaskets and I thought there was a recall for it years ago??? I would have a mechanic rule out the possibility of an external leak like from the valve cover gasket, PVC valve etc. etc. before I pulled the cylinder head off this vehicle. If you DO remove the head for some reason, I would highly suggest you take the head to a machine shop and have them do a valve job on it while it is off the vehicle. You will get a much better job in the long run for a few dollars more.

  167. Keith says:

    What can possibly cause low oil pressure while car was idling my stop engine low oil pressure light came on so I didn’t take the drive yet. any suggestions?

    • Austin says:

      Few things can cause the low oil pressure light to come on

      1. engine idle speed to slow
      2. bad oil pressure sending unit, giving the dash gauge false information
      3. Worn out engine
      4. Problem with oil pump or a clogged oil pump screen
      5. Contaminated engine oil – like with coolant

      Obviously I would rule out 1,2 and 5 first

  168. John says:

    I have a 2000 Mazda Protege LX 4 cylinder, 1.6 5 speed stick. It overheated and stopped twice within the last week (not me driving…it must be his fault!), due to faulty belt on water pump. Belt replaced.

    Afterward, I was losing coolant. The coolant reservoir was cracked, so had it replaced. No white smoke from exhaust, but I do get white smoke from the radiator if I leave the cap loose or off, and from the reserve tank if the cap is tight. Reserve tank also “bubbles”. Oil appears to be fine. Color of coolant is fine.

    The car actually runs when the coolant level is good, and does not overheat. I’ve been told this is a blown head gasket or cracked block.

    Sound like something that K&W may fix?

    • Austin says:

      You did get a cooling system pressure test….right? This does not sound like a head gasket problem from what you have told me. Maybe a restricted radiator or some other coolant leak externally of the engine. Sealer will not help those problems. Get a second opinion.

  169. Keith says:

    Last quick question should I allow the car to warm up before journey of 500 miles or during?

    • Austin says:

      Unless you live in Alaska, the car should warm up with no problems as you start your journey. You DO NOT need to drive 500 miles at once, just total before you drain the sealer mixture and re-add the coolant. However, would be a good idea to take as long of a one time journey as possible just to give the sealer the best opportunity to work. Take a few gallons of water with you. :0

  170. Keith says:

    Do you know anything about steel seal? just curious.

  171. Keith says:

    Trying it this morning after oil change.

  172. Keith says:

    Is K&W good if cooling system fluids has already started to mix with oil

    • Austin says:

      Yes. if you see coolant mixed in with your engine oil that would be a pretty good indication that you have some type of internal engine coolant leak….like a head gasket failure. That is exactly what the K&W sealer is made for.

  173. david says:

    alright. on my third round of K&W the first two times i used the nanotechnology bottles, this time i used the regular. i am at about 150 miles, the car is still leaking fluid, i find the coolant reservoir full and that is where i believe most of the water is leaking from. any advice sir? thanks.

    • Austin says:

      The K&W sealer will ONLY repair an INTERNAL coolant leak inside the engine combustion area of the engine. If you can physically see a coolant leak with your eyes, or you have an EXTERNAL leak like a coolant reservoir, radiator, water hose, water pump, freeze plug etc. etc. the sealer will NOT repair that kind of leak. Since you have run 3 cans of sealer into the system I can only assume you DO NOT have an internal engine coolant leak.

      If the coolant reservoir is leaking you will need to replace it with a new one from the dealership. You really need to rule out all possible external leaks, get a cooling system pressure test FIRST which should rule out most external leaks and it should tell you if the cooling system can hold pressure. If the system is holding pressure with the pressure test, then you have some other coolant leak or overheating issue which needs to be diagnosed.

      Common symtoms of an INTERNAL coolant leak inside the engine are.

      1. White smoke out tailpipe
      2. Engine missfire due to coolant getting on spark plug
      3. Check engine light on because of the engine miss fire
      4. Water/coolant getting inside the engine oil which makes it look like a chocolate milkshake
      5. Loss of power due to coolant getting on spark plug
      6. Overheating
      7. Continual loss of coolant in the radiator

      I would find another mechanic and start with a pressure test of the cooling system for leaks. A COMPRESSION test is different than a pressure test. Compression testing will check each cylinder to see if there is internal wear on the engine. A pressure test places pressure on the cooling system looking for leaks. You should be able to apply pressure to the radiator via the pressure tester and it should maintain that pressure.

  174. Chad says:

    Thanks for the reply Austin,

    I’m definitely doing it your way. I know that these Isuzu’s are bad about head gaskets. Mine had a small leak so I am hoping it works. It would use about a 1/2 a gallon in 600 miles of highway driving at 65-70 mph @ 2800 to 3000 rpms.

  175. Chad says:

    Dear Austin,


    I am just curious about the two totally different theories: (directions on the can versus yours)

    I agree that both the can and you both say to completely rid the system of antifreeze as the K&W is not compatible with it and will not work with it.

    (so did that)

    For those having problems getting it all out an easy way that I tried was to remove the top hose and start the engine. When the engine warms the thermostat will open and water will run out of the top hose. Then just keep adding water into the radiator as it lowers. Keep doing this until the water runs clear out of the top hose.

    Anyways the part that concerns me is:

    The instructions on the can of K&W state to idle for 30 minutes do not race engine or drive it, then after 20-30 mins drain the entire system and let dry for 24 hours. Then add back your 50/50 antifreeze water mix.

    It just seems like two totally different theories/directions.

    I am trying your way first. I only drove it for 20 miles so far but as I am typing this it is idling in the driveway and I plan to let it idle for 5 hours or so. That should equal 500 miles or close to it.

    So have you ever tried it exactly how the can states? Emptying after 30 mins and letting dry?

    Thanks in advance,

    PS: This is on a 1988 Isuzu Trooper II with a 2.6 liter aluminum head cast iron block engine.

    • Austin says:

      Yes, I know its confusing…..and yes we had tried the directions on the can multiple times before we gave up on the idea. One day we decided to try the product another way and we experimented with different method until we finally found one that worked most of the time and we have been doing it our way for years now. Driving for 500 miles seem to be the key.

      Your vehicle is VERY susceptible to head gasket failures ๐Ÿ™ DO NOT SKIMP!!

      Keep us posted on the outcome.

  176. david says:

    yes, head gasket job done about a year ago, possible crack in block or headgasket again. pressure test failed. coolant reservoir filling up and radiator is a little low each day, have 250 miles since the second round of K&W. the vehicle is a 1999 subaru forester. thanks in advance for any help.

    • Austin says:

      I can only suggest you either continue to put 500 miles on the engine with the sealer or have the engine torn down and repaired. I think those are your only two options, sorry

  177. Woodrow says:

    David with the 1999 Subaru Forester,

    My 2000 Forester didn’t stop leaking significantly until after 500 miles, and it was a slow process.

    My theory: I had an external leak and I believe K&W was so slow working because the sodium silicate sets slower in a “cool” leak.

    That is, K&W works fastest under highest heat, as you’d expect with an internal “hot” leak that is more likely to be nearer the the combustion chambers, with higher pressures as well.

    Austin can correct this speculation.

  178. david says:

    okay flushed radiator as stated above 5 times. added the K&W, have put 200 miles on the car so far and am still leaking water, not as much it would seem. any advice? thanks.

    • Austin says:

      I am lost on this thread, so forgive me of my lack of memory. Why are you flushing the radiator? Did you get a cooling system pressure test from a trusthworthy mechanic??? Is this an external or internal leak?

  179. Stuff says:


    I am at a loss, and most likely it is my fault.

    I have a dodge 2001 Caravan, when I first bought it, their was major pressure in the coolant system, I ran a bottle of some other kind of head gasket repair, and it did a good enough job to get by for over two years. There was always high pressure, if I topped off my coolant, it would blow out about a half a gallon and then stop.

    About a month ago, after I would go somewhere and the engine was stopped, the overflow would spew out coolant and a sludgy oil mess.

    I read this post, I got the K&W, followed the instructions on the bottle for clearing out all coolant, I ran the car at idle for about 2 hours with the K&W, let it cool, drained the car, then moved it into my garage, as I am in Utah and it is well below freezing this time of year. I let it set for about 3 days, because of the temperature, hoping it would dry out. Flushed it, and now with just water in it, I can see a steady stream of bubbles coming up and out of the cap.

    I just completed my 3rd bottle if K&W and still no go, however, I did run the second treatment for about 130 miles straight.

    Am I causing this to blow back open, when I drain it outside, then pull it into my garage? Also, when you say to drive it 500 miles (stupid question here, but…) do you mean drive 500 non-stop?

    What can I do? I need to get my car back on the road…

    Any help would be fantastic.

    • Austin says:

      I wonder if you have a restriction in the bottom of your radiator causing low coolant circulation and over heating and boil over. I would get a coolant pressure test to determine if you have an internal or external coolant leak. You have not mentioned any tell tale signs of a headgasket or internal coolant leak. Yes 500 total miles but the sooner the better

  180. Dwayne says:

    i have a 97 dodge stratus and my girlfriend was driving it home and she said it made a bang and a lil smoke came out the tail pipe. i had the car towed gto her parents house where it sat for a month. i just had it towed back here and wanted to change the fluids and plugs before starting it. i went to change out the oil and nothing but antifreeze came out at first then oil. Blown head gasket? and do you think that the head could of warped that quickly?

    • Austin says:

      If you had that much antifreeze drain out of the oil pan you most likely will need to remove the cylinder heads for inspection of the engine block and head. I would send the head to a machine shop and have them check it for cracks and do a valve job while they got it.

      Orrrrrr, if the engine will start and run you can try the K&W sealer I talk about and cross your fingers.

  181. david says:

    thank you very much, will try right away and keep you updated.

  182. Woodrow says:

    David and Austin,

    On the 1999 Forester, assuming it is the same as 2000 Forester, my protocol was the following after consulting Subaru experts:

    Front of car must be higher than rear, say on wheel stands.

    Remove radiator cap. Remove overflow reservoir. Remove cowling that protects bottom of engine compartment (as when you change oil filter).

    You can wait forever draining cooling system partially using petcock on passenger side, bottom of radiator, but this is a poor method. Instead, on driver-side bottom, there’s a short radiator hose connecting radiator to thermostat. Loosen hose clamp at thermostat, back it off, then pull hose off thermostat. Have large pan ready to catch gushing water.

    Pour distilled water through radiator rapidly in order to wash out extra coolant.

    Reinstall radiator hose; reinstall overflow reservoir after cleaning it out, then fill it with distilled water to min level at least. Reinstall radiator hose to thermostat.

    Fill cooling system very slowly with distilled water, with up to 50% white vinegar if cooling system is dirty (I used a half gallon).

    Leave car on front stands with cowling removed, and run engine at 2000 rpm for about 5 minutes. Watch temperature gauge to be sure thermostat opens and water is cycling through cooling system.

    Turn off engine and let cool enough so you can safely open radiator cap. Drain cooling system as described previously, but this time forget about removing the overflow reservoir.

    Fill the cooling system, but only with distilled water. Run engine as before for a second flush, draining system, etc.

    I repeated this flushing process 5 times, based on someone’s calculations for removing nearly all antifreeze from the cooling system, which is critical for Austin’s K&W method to work most effectively. The first time K&W didn’t work for me, perhaps because I only flushed system twice.

    Use Austin’s method, add K&W with distilled water. Run engine on front stands for several hot-cold cycles to be sure air has been burped out of cooling system.

    I ran vehicle for 1000 miles during summer when I had no fear of freezing temperatures. Constantly check reservoir in case air in system.

    After K&W does it work, for your Forester (I believe all 1998-2002?), fill cooling system using only the Subaru antifreeze (blue) and you must add the small bottle of Subaru Cooling System Conditioner. This is critical.

    Sorry to be so wordy, but I wish someone had told me this the first time. Austin can correct me on any misguided advice, since I’m recalling what I did many months ago.

  183. david says:

    thanks, how do i get the coolant out of the block? i have a 1999 subaru forester. thanks for all of your help.

    • Austin says:

      Easiest way, drain radiator via drain cock on bottom. Fill radiator with water and run engine to operating temperature. Let cool, then drain radiator again…should have removed enough coolant for the sealer to work properly .

  184. david says:

    now when you say to remove the coolant in the system, are you talking about draining the radiator only or to drain the coolant out of the block? thanks

  185. Ferney says:

    Well Austin, the sealer worked this time better than before. I’ve put about 500 miles on it and still no white smoke. This time i bought the more expensive one that has some type of nanotechnology. Thank you for the advice.

  186. david says:

    thanks Austin, yeah had the head gasket repaired about a year ago and now the mechanic says crack in the block. ok ill empty the mix today thank you.

  187. Ferney says:

    Hi Austin, i just wanted to update for the Honda Prelude, i wanted to assure you that i did everything i could. Before i put in the block sealer i had a pressure test that failed and was experiencing a lot of continuousness white smoke. I changes all my cooling system hoses and thermostat. I also experienced overheating multiple times. I cleaned out the cooling system and added the block sealer plus only water, 150 miles later and my white smoke started again. I had another pressure test and failed again. What would be your recommendation?

    • Austin says:

      There are only two choices here, either remove the cylinder head and have a valve job done and replace the head gasket or try the sealer again and cross your fingers…..harder. ๐Ÿ™‚ The sealer does work… most cases although there is always an exception to the rule. I would try the sealer again, grab lunch and hit the road around your town for a few 100 miles if possible on a nice day. Bring extra water just incase.

  188. david says:

    im at about 140 miles with just the K & W water mix, is it normal for the car to run warm? also how fast should i put the 500+ miles before i change to the coolant mix? thank you.

    • Austin says:

      If its as cold as it is here in Houston right now, about 40 degrees I would not expect the engine to run warm/hot unless there was a problem like a restriction in the radiator or low on water in the radiator etc. etc.

      Hopefully you got a cooling system pressure test FIRST to determine that you do in deed have an internal coolant leak and warrant using the sealer in the first place. I hop you did that AND ruled out any other issues like radiator restriction, cooling fan operation etc. etc. and used the sealer as a last ditch fix for a costly internal leak.

      You might want to get a pressure test NOW and if the water level is FULL in the radiator today with the sealer and you are not experiencing exhaust white smoke, or engine missfire then you can probably remove the sealer and go back to water coolant mix.

      Please make sure your mechanic has ruled out all other sources of overheating. I see people jump to head gasket conclusions and use the sealer when they really need a new radiator or electric cooling fan or something along those lines the sealer will not fix.

  189. Shurtliff says:

    I have a 94 Acura Legend GS with antifreeze leaking from the engine and oil sludge found in the radiator. I am ready to try KW block sealer as suggested above but am concerned with freezing temperatures at night. I don’t have a garage and it commonly goes below freezing to about 20 degrees. What is the freezing point of KW block sealer with water? I have considered two ideas, let the engine idle and stay warm over night or put a space heater under the hood at night. Will letting it idle for long periods of time be similar to driving X number of miles? Do you have any thoughts or suggestions?
    Thanks for your response

    • Austin says:

      Did you get a cooling system pressure test!!!!????!!! DO that first. No skimping a few bucks to jump to conclusions about a head gasket issue. Some oily substance in the radiator would not be enough for me to jump to that conclusion. The sealer mix will freeze at 32, its basically just water.

      So, if you are sure you have an internal leak and the pressure test confirms it, try the sealer and take a long drive around your town for a few hours and put 100+ miles on the vehicle if you can. I would suspect the sealer will do its job in that time frame since you did not mention white exhaust smoke, missfire, water in oil etc. etc that would be a clear sign of a major internal coolant leak.

  190. hisham says:

    I’ve Honda Civic ’97 and overheating while idling. Changed rad cap, thermostat, flush radiator, problem persists. Fan is working fine. Every morning, cold engine, reservoir tank always full and radiator is empty. Move some of the coolant from reservoir to radiator until it full. That’s my routine every morning before starting my car. No white smoke or visual coolant leaks though. I am guessing pressure leaks to cooling system and thus the full reservoir. Since there is a leak, coolant is not sucked back into radiator overnight.

    I’d like to try your suggestion. Which one should I use?
    K&w Permanent Metallic Block Seal OR
    K&W NanoTechnology Permanent Head Gasket & Block Repair

    It’s hot climate here in Malaysia, 82-92 degress. Since I don’t have boiling protection and following your article, will it be ok to run the car for 500 miles? Of course I’ll bring extra water just in case.
    Thank You very much.

    • Austin says:

      You have not convinced me you have an internal coolant leak. Get a cooling system pressure test FIRST then recheck the cooling fan operation and check for a radiator restriction. If you are still convinced there is an internal engine leak either of the sealers will be fine, the Nano is their new product.

  191. matt says:

    I have a 1996 subaru outback with the 2.5l engine. they have an issue with the block cracking between cylinder 2 and 3 into the oil galley once they have been overheated due to a thermostat being stuck. i think this may have happened with my car. i have noticed oil in the cooling system and was wondering if you think the k&w sealer will work. a new engine is 4500 bucks and i was just trying to buy some time. let me know what you think.

    • Austin says:

      I am not familiar with that issue but if you are sure that is what is happening to your engine I would definitely try the K&W, I don’t see how it can hurt anything. Keep us posted as to what happens would ya?

  192. tyrone says:

    why would I need 1 my car still gets up to the operating temperature of 180 and stays. when I woke up this morning and started the car up I still have the same problem as yesterday before k&n. But not as bad. Have driven almost 100 miles.

    • Austin says:

      Operating temp is 210 degrees. I would suspect the thermostat was removed because the engine was overheating?? A clogged radiator that is restricting the flow of coolant could be your problem. If you did the cooling system pressure test and there are NO leaks, either internal or external and you are still having overheating issues I would turn my attention to checking the radiator for a restriction. In any case, a computer controlled vehicle needs a 195 degree thermostat and should operate at 210 degrees to operate properly.

  193. tyrone says:

    I have a 95 camaro and i had the test done and was told that my head gasket was blown. I read everything on hede and decided to do the test with the k&n nanotechnology one and drive the 500 miles. I used a tee back flush kit to make sure all coolent was removed then added the k&n. I never had a thermasat so the car always ran cold. After adding k&n i noticed the temp staying at about 180. (always 160 or below normally) also the car is running better. Will post through the 500 miles.

  194. ARN says:

    I have a 2005 Scion TC with 70,000 miles on it. On the radiator reservoir the substance is very milky and and mix of oil and the same signs inside the radiator. The oil is fine, there is no signs of water and no white smoke coming from the exhaust. Can it be signs of a bad head gasket or should i spend the money on performing a cooling system pressure test or just use the K&W. Whats your advice

    • Austin says:

      It could be signs of an internal coolant leak, like from a bad head gasket or it could be pretty normal condensation. If the radiator is low on coolant or you have to add coolant on a regular basis, yes, get the cooling system pressure test to find out where the coolant leak is and repair it. I would NOT use the K&W sealer yet, until you have proven that you do indeed have an internal coolant leak…which you have not convinced me that you have.

  195. Ferney says:

    My car is running pretty well, the 92 Honda Prelude. Before i did anything with the K&W i had a pressure test and did a test for the head gasket. I do have a blown head gasket, but not blown but warped, its not flat. So my car was leaking inside and filling with water, thats why it didnt start, 100 miles with the K&W pretty much fixed that. My car is also leaking externally right at the junction between the head and the block. The leak is variable, i dont know what to make of it. It is a coolant leak, or rather water leak. Thank you for all your help. I dont really think i can avoid this external leak. Any ideas?

  196. Ferney says:

    Hello, I drove my car for a good 150 miles, he was still heating every now and then. So i decided to do an oil change, not heating up that much but still heating after another 150 miles. Will this K&W also resolve a leak that is visible on the outside of the car, or is it only meant for internal leaks? Here is the thing, he is leaking pretty bad, but not always, when i did the oil change, there was visible water in the new oil after puring it in. Should i flush it out again change the oil one more time, and put the K&W in once more?

    • Austin says:

      The sealer is for INTERNAL COMBUSTION leaks only. All external leak must be repaired! You should only need 1 can for the 500 mile duration period I suggest. You can change the oil, if its full of water, that is a good thing to do.

  197. Cisco says:

    Hey there Austin. I just picked up some K&W Sealer. My symptoms are: leaking anitfreeze to a small small puddle, no power, heater blows kinda cold. I am in Colorado, so it is pretty darn cold right now. I do not have a garage to park and keep the truck warm in to sit over night. What are your suggestions? I did read that you said to drive it for a good amount of time but will it work properly by just driving it and then draining it after a good mileage number is meet to refill with the proper mixture of anti/water? I am just worried about it freezing. Thank you ahead of time sir.

    • Austin says:

      Get a cooling system pressure test FIRST!!!!! I am NOT convinced you have an internal coolant leak from what you have told me. Checking beats guessing….and its much cheaper in the long run.

      If you have an INTERNAL coolant leak, yes, the K&W sealer would be a great suggestion. Maybe you can place a 100Watt light bulb on a drop light under the hood to keep the engine warm and leave the radiator cap OFF to allow for freezing/expansion? I am from Houston, and not that familiar with cold weather….thank God. ๐Ÿ™‚

  198. Jeff says:

    My local parts store carries Bar’s Leaks brand? Is there any reason this wouldn’t work just as well as the K&W or should I get the K&W just to be sure?
    Going to be using it on a ’96 Chevy Cavalier. Thanks.

  199. Ferney says:

    So, i took out the plugs lubricated them and put them back in. I also drained out my cooling system and filled my car with K&W plus a lot of water, my car can hold a lot of water. Should i add a second can of K&W? My car turned on and, at first he wasnt staying on unless i was constantly gassing it. Now he stays on with out a problem and runs well, he does not overheat. He will not stop leaking though. A leak that was not there before, the leak is just watter, but it seams to have a slight mixture of oil. I was only able to run the car while it was parked because it kept on turning off, So i just kept it parked and gassed it for 2 hours.

    Thank you for this great advice. I will keep updating.

    • Austin says:

      Cool, keep us posted. Take a few gallons of water with you and take a road trip around your town until you put 100 miles or so. Keep sealer in system for 500 miles total if possible

      One can should be plenty

  200. Ferney says:

    Well, I changed the spark plugs, they were very hard to get out, and they were wet!!! I started the car and white smoke began to pour out of the pipe. I have a blown head gasket. How do i know if i just have a blown head gasket of if there is more engine damage. Here is the other thing. The car will not start now. The plugs are so wet that it wont spark. Im thinking i will try this sealer, but what happens to the water already inside the head?

    • Austin says:

      Try draining out the cooling system and blowing out the cylinders with compressed air then install plugs and run engine with cooling system empty. Slowly add KW and water mixture with engine running.

  201. Omar Denison says:

    I used the K & W sealer, ran the car for 1.75 hrs, white smoke then left, now i am waiting the 24 hours required. Will give update 2 morrow.

  202. Ferney says:

    Hello, after a lot of searching i came upon this site. I’m trying to go to college so i have no money for a new head gasket. I drive a 92 Prelude, love the car. Was having a lot of leaks and hoses go bad. I replaced my radiator, hoses, thermostat, fuel filter. I haven no leaks but i do have white smoke every now and then from the exhaust and my car does not overheat any more. The main thing is that when i gas the car, it seems like it has a very hard time sucking the gas. Like there are air pockets with my gasoline. Could this really be a blown head gasket. This was not happening before i started having issues with my heating. Now that i fixed the overheating, i this popped up. Thank you!

    • Austin says:

      You did not mention anything that would lead me to believe you had a blown head gasket besides some occasional white smoke out the tailpipe which could be normal condensation. I would not recommend using the sealer at this point if that is your concern.

      I would however advise you have a mechanic take a test drive with you and let them experience this issue and get their opinion. This could be a fuel pump or tune up issue? The sealer is mainly used as a last ditch option for costly head gasket repairs. Hopefully this is something simple.

  203. Bruce says:

    Just giving an update on using the K&W on my 98 Cadillac Eldorado with 4.6 Northstar engine. So far the cars been running great. Over 200 miles on it with the sealer still in it. Thanks for the advice Austin.

  204. Pablo says:

    Austin Wow This stuff really works I thought my motor was doomed after the first half hour of adding the K&W Block Sealer I bought at Walmart it showed less smoke after the first 100 miles I had no smoke at all from the tailpipe.I only had to add about 1oz of watter to Radiator compaired to over 16oz before I used this stuff. I have one question though Do I still need to let it dry for 24hrs after I drain and flush the radiator after the 500miles? Thanks for the advice….. Pablo
    I really do recomend this stuff to everyone!

    • Austin says:

      Personally I have not let the radiator dry for 24 hours after putting 500 miles on the engine. Just drain out the sealer mixture and refill with water/coolant mix and cross your fingers.

  205. Dan says:

    I also am living in a cold climate with no place warm to park. (It’s dipping down into the 20’s lately.) Do you think a block heater (either the magnetic type, or the freeze plug style if I can get the darn plug out of my rusty Durango) would be adequate to keep the K&W mixture from freezing?

    Also, my vehicle holds 14qts of coolant. Is one can of the K&W enough? The instructions don’t mention capacity at all.

    Thanks in advance.

    • Austin says:

      You might be able to place a drop light with a 100 watt light bulb under the hood? I do this with my boat and seems to generate enough heat to keep from freezing. You might also want to remove the radiator cap and allow expansion room just in case.

      1 can of sealer should be enough.

  206. John says:

    Just wanted to thank you for this page. I tried you suggestion. I have a 2005 Chevy Impala, with a messed up head gasket and 120,000 miles on it. Tempurature gauge would go into the red when stoped within 10 second but could cool down once going again. Used the sealer per your instructions. I put it in and idled for 45 min then let it sit 24 hours, but I didn’t open all the ports on the enging. Ran it for about 1200 miles. Drained and refilled. Haven’t had a problem since. It’s been running good for almost 20,000 miles now. Thanks so much for the help. Would recommend anyone try this. I mean what have you got to loose? $20? Again thanks so much.

  207. bry says:

    i have a combustion leak into the coolant passages. no other leak can be found. no thermostat because someone fixed a pluged radiator overheating problem this way. im in ohio and its cold as antartica right now. no garage with heat but my buddy has a garage. any advice on what i can do ? i can drive it for 100 miles but without a thermo, it doesnt get up to temp plus the a-f blows out the overflow. any advice besides a new headgasket would be appreciated.

    • Austin says:

      You can try the sealer the way I describe in my original article but take the vehicle on a 100? Mile or so drive around your town with a few extra bottles of water for the radiator if needed.

      I would make sure you do not have an external coolant leak or a restriction in your radiator before using the sealer.!!!!

      You will not have freeze protection with just water and the sealer so drain it and add antifreeze once you have make your tour around town and park the vehicle

  208. e says:

    the directions on the bottle mention removing corroded spark plugs and disabling fuel injection to them. you don’t mention this. did you skip this step when you performed the procedure?

  209. Joe says:

    Today I recently ran into cooling problems and I have white smoke, no heat and the smell of coolant but there’s is no coolant in the oil and no oil in the coolant. I also have power loss. I suspect the head gasket is the culprit. I will be doing a coolant compression test tomorrow. My question is though I live in Wisconsin so it is cold this time of year and I do not have a warm place to store my car. What is the importance of just using water with the sealer? Do you suggest I not use it since I will not be able to use it with water only since the cold temperatures here?

    • Austin says:

      You need a cooling system PRESSURE test first. You can not have antifreeze in the system with the sealer. I just told another visitor, spend a weekend driving around your town until you have put 100 miles on the sealer mixture. I would also carry extra water with me just in case. Then replace the antifreeze and cross your fingers that 100 miles was long enough.

  210. Tony says:

    Hello Austin,
    It’s below freezing and I don’t have a heated garage to park my car in. Will the K&W Sealer still work with antifreeze in the radiator?


    • Austin says:

      No, will not work with antifreeze! You will NOT have freeze protection with just the sealer or water, so you take a chance of doing more internal damage to the engine or radiator if the water freezes. Maybe you can use the sealer as I describe in my article and spend a weekend driving the vehicle around your town for 100 miles or so then remove the sealer, add back to the antifreeze and cross your fingers.

  211. Pablo says:

    Hello Austin my car recently started to use up coolant and now my car started to throw white smoke from the tailpipe and idels rough when i come to a stop of first start it after have ben driing it for awhile. I will be trying K&W sealer this week and I was wondering since I only use my car for work is their a limit on how many days it should take for me to make it to the 500 miles Because it might take me about 2weeks as I do not drive much? Thank you very much for the help I will keep you updated on my results..

    • Austin says:

      I would grab my favorite music CD’s, a few gallons of extra water for the radiator and head off on a tour of your town one weekend…..least 100 miles.

  212. UJ says:

    Hello Austin,
    I read this article on web when I was searching for my car’s coolant leak problem. I have it tested and it has a Head Gasket leak. I have purchased “K&W Head Block sealant with Nano Technology”. Is it the same product that you have mentioned in your article? Instruction says to drain it after running car idle for 30 minutes or it could cause damage to engine.
    What is your advice? Should I run for 500 miles with it?



  213. jonathan richard says:

    is there a temporary fix in the mean time till i can afford a heater core and rerouting the heater core hoses won’t work as i need something to defrost my windows unless it’s possible to use a 12 volt electric heater that plugs into the lighter outlet

    • Austin says:

      The “by pass” is the temporary fix. Not sure if your heater/lighter idea will work…most electric heaters draw a lot of current, more than the lighter can probably deliver.

  214. jonathan richard says:

    ok only problem is that i don’t have the cash to fix it and it is very cold where i live

  215. jonathan richard says:

    hey this is john. i have a 1986 pontiac parisienne with a 5.0 L v8. problem i’m having is that i am getting huge quantities of antifreeze misting in my vehicle causing windows to fog up and feeling nausious after just 20 kilometers of driving. my car requires 3 litres of water every 200 miles of driving. anyways i picked up some CarGo Seal-Up liquid glass metallic and need to know if by the quantity of antifreeze i’m loosing will be sealable with this stuff? the bottle claims to be a permanent fix and being as i have corrosion in the radiator is this stuff going to coat the corrosion and cause the radiator to plug? if anyone can help me with this i would be very appreciative and thank you so much for your time and help

    • Austin says:

      John, do NOT put that stuff in your radiator. You have a HEATER CORE leak, which is not that big of expense…compared to a headgasket.

      if its not cold where you are and dont need the heater or on a tight budget have your mechanic “by pass” your heater core so it stops leaking.

      Here is more info about it

      Heater Core Leak

  216. marc says:


    Just wanted to do a quick review on the K&W sealer. I was a little skeptical of it, being that I worked in a repair shop for a few years, I always thought that skimping on things of a serious nature will always come back to get you.
    Well after trying the product I would recommend it to anyone that needs to get their vehicle running without breaking their bank. I wouldn’t suggest it as a permanent fix, although from what I read, its possible.
    Just follow the directions it says. Make sure ALL coolant is drained, I used a prestone back flush and radiator flush additive just to make sure it is all out.
    Also I decided I would let my truck idle for a little over an hour with sealant running through it with heater on highest setting, and let it sit over night ( 24 hours) with no issues the next day with start up.
    One last pointer is I would change out the oil as well if it was an internal leak. Even though it didnt seem to be doing a whole lot of damage, but you vehicle will thank you later. I also decided to use an oil flush additive as well just to make sure I got everything out, and as of now, the truck runs better now than it did when I got it. ( used)
    Thank you for reading and I wish you the best of luck!

    • Austin says:

      Awesome, thanks Marc! It’s really one of the few “miracles in a can” that I have ever seen out of all the products available at the local auto parts store.

  217. Hannah says:

    Hi Austin. I need your help! I have a 2002 Chevy Malibu LS and have a blown head gasket. I picked up the product K&W Head Gasket and Block Repair. It suggested I take out the Thermostat. Well I tried, and failed. As being I am female, and have lack of MV experience, after almost 12 hours under my hood I finally caved and found this website. (My finances blow and can not afford a mechanic) So please help me. Can I drive with this solution in my vehicle? I have work tomorrow and this is my only transport!! And thanks for taking your time to help.

    • Austin says:

      I would try the sealer as I described in my original article. You do not need to remove the thermostat, and yes you drive around with the product in your cooling system (with nothing but water) for about 500 total miles. You will not have freeze or boil over protection since there is no antifreeze!

  218. LilEngine says:

    I just wanted to update and say my car is still running fine. It starts a tiny bit slow on cold days but it always starts and runs. The sealer has been out for 200 miles now. My last post was 6/28/2010

  219. Bruce says:

    I already got the pressure test done by a mechanic and it’s the head gasket, the coolant keeps coming out of the overflow hose and i got very light white smoke. I can even drive the car for miles without overheating i just have to add anti-freeze once every 2 weeks or so….i’m thinking of trying the k&w sealant..

  220. SpookySr says:

    Tell these people who are NOT following K&W (CRC Industries) instructions properly are just asking for trouble! What’s this nonsense about just pouring in the block seal without premixing it with 3 qts hot water? What’s this driving for 500 miles with block seal liquid STILL in? This is insane! Follow the darn instructions to the tee and stop this crazy DIY insanity. The product was designed to work a very SPECIFIC way. These people don’t understand the basic science behind it. Read the literature & instructions here:

    To all of you other folks go on Internet (Google) and learn how a automotive cooling system works first. It is relatively complex system of interdependent systems. If you don’t have a basic understanding as to what’s going on, how can you try and fix it yourself?

    Many of you may just have heater core issues (that’s inside the passenger section under the dash). If only you knew how many man hours it takes to drop the dashboard to get at it. The labor cost will stagger your mind! Many people overlook this as the culprit. And a core is not that expensive sometimes (i.e. Auto Zone $60+ bucks). But an old rusty leaky heater core under your dashboard can just ruin your pocketbook and your day.

    • Austin says:

      Everyone is entitled to their opinion, and I thank you for submitting yours. My family has been in the auto repair business since 1937 and our shop is as large as any big town Chevy dealer, so we are not some small fly by night oil change place. We have used the product 100’s of times and with great success BUT very limited success as described on the can. We came up with our own process of using the product and have stuck to that process for years……..and it works.

      You can see comments from people who have tried the product in the past as directed with NO success and when they tried my method it worked. I am only passing on information that we have developed over the years of testing and trial and error.

      In my opinion, if your options are an expensive head gasket repair or engine replacement I would try any other solution available to me. I am offering that alternative solution to those folks.

      In your response to heater cores leaking, I ALWAYS suggest (see all previous comments) to get a cooling system pressure test FIRST and use the sealer only as a last ditch effort once an internal coolant leak has been proven. You are correct most headgasket diagnosis claims are incorrect due to lack of a proper pressure test.

  221. Bruce says:

    i have a 98 cadillac eldorado, it tested posetive for failed head gasket (after i bought upper,lower hoses…radiator/thermostat) my question is…have you personally had success using the k&w sealer on northstar engines ?

    • Austin says:

      Personally no not on Northstar. You should call the K&W company and get their opinion. I think it will be fine since the product works on aluminum but better safe than sorry. Although if you have an internal coolant leak you are already sorry:(. I would HIGHLY suggest you get another mechanic to perform a cooling system pressure test first. I have seen issues with the intake manifold leaking coolant.

  222. John says:

    Hello i have a 97 cadillac eldorado and im haveing an overheating problem i changed the thermostat and im pulling out the water pump tomorrow. I put coolant in and these tablets in the lower radiator hose,as directed, and drove it for 15 min and it overheats.. any suggestions

    • Austin says:

      Get a cooling system pressure test to see if you have a coolant leak somewhere and also check the electric cooling fan motor operation and check for a restriction in the radiator.

  223. Al says:

    My ’94 corsica blew a head gasket as evidenced by heavy white smoke blowing out of the tailpipe along with a loss of coolant. I’ve added several quarts of water each day to get by for now. Suddenly, I’m not losing that much coolant and I no longer see any white smoke. Can the head gasket somehow reseal itself by getting full of oil or water?

    • Austin says:

      No it won’t fix itself. I am not sure why the smoked stopped I would get a cooling system pressure test to see if you really do have an internal leak or not.

  224. Alex says:

    Hi. I’ll try & condense this as much as possible. I have a ’01 Hyundai Elantra that had oil in its coolant (i’ve known this for awhile)but there were no performance issues with engine or cooling or symptoms of HG leak. The other day, its upper radiator hose burst while I was driving on the frwy. I kept driving ( with slight engine hesitation & ping)to the closest exit keeping an eye on the temp gauge which stayed about 1/4 below “H”. As soon as I exited the off ramp & came to a stop, the engine sputtered, pinged & died & steam went off under the hood. A few days later I started repairs. I replaced all cooling hoses finding oil milkshake in only the upper & lower hoses & the radiator. Bypass hose was clean. I completely cleaned radiator, other parts & finished repairs. When I started the engine, it ran very rough, hesitations here n there, & then died. started it up again and it ran a few minutes then sputtered & died. Havent checked plugs yet for indications of anything but do you think headgasket went from leak to blown? If so, i hope this is a situation where the K&W would work well. Please advise. Thanks.

    • Austin says:

      I THINK you might have killed this little engine with overheating. I would do a compression test but I would highly suspect you will find two very weak cylinders. I would then remove the cylinder head and send the head to a machine shop and have them do a valve job and verify the head is in good shape. The sealer is not going to help in this situation, sorry.

  225. Brian says:

    Austin, I did find the K&W Head gasket repair stuff and i used it. The car still runs hot after a lil while of driving. But tomorrow, I’ll take it to the mechanic and get him to look at it and do a pressure test. I’ll let you know what he says.

  226. Sergio says:

    have 2001 chevy venture. Its been running hot after 10mins running. at times it will cool down but jump to hot various times. there seems to be no coolant in the oil or oil in the coolant. no smoke or water out of the tail pipe. fans seem to kick in as necessary. there is no heat when i turn the heat on, only when the engine cools down while driving.i have a feeling its a stuck thermostat. any suggestions?

    thank you

  227. mike says:

    i have a 97 rodeo, i’ve had a mechanic do the pressure test, said its fine, then replaced an o-ring near the water pump, he said pump was ok, then heater coil hose broke, currently bypassed the heater coil, then my radiator blew, just replaced that, now i have white smoke and coolant coming either out of/or dripping onto(i believe out of) my flex pipe in the exhaust system

    • Austin says:

      Wow! bad luck in deed…..not convinced its a headgasket OR anything other than an EXTERNAL coolant leak, get another pressure test. ๐Ÿ™

  228. Brian says:

    Hey Austin. I could not find the K&W Head repair thing. But i was able to find Bar’s Leaks Head Gasket Repair. Would this be just as good?

  229. Caty says:

    I have a 1995 neon with a 4 cylinder 2.1 liter engine and its leaking white smoke not through the tail pipe but coming from the hood, i forget exactly were. Everyone i talked to said it was the head gasket or the engine, if i were to use your sealer would it still be 500 miles in pa? Would it work on the engine as well cause thats what the container says but yea never know with products. And also since its not weather proof, the car that is, would it be wise to do it now that its getting cooler out? Ty 4 ur time

    • Austin says:

      Get a cooling system pressure test!!! You probably have an EXTERNAL coolant leak, not an internal coolant leak like a head gasket.

  230. Chris says:

    His coolant looks like chocolate milk, and the car overheats almost immediately and you dont think he has anything pointing to a blown hg?!? hmmm. reading your advice leading up to that post id agree w/ most everything youve said, but i would bet $$$ the HG is GONE in that 3.5 oldsmobile.

    at any rate, i came across this page looking for input/review of the kw block seal because im considering giving it a shot in an old pathfinder that i have which has started to run a good deal hotter than it should. the fan clutch had given up, and it was driven too long at too high a temp im afraid, because now (after installing a new clutch) it will not stay within a safe temp range without running the heater and staying gentle w/ the throttle. checking the coolant, it looks as if you dropped charcoal into a glass of water. flushed the system, swapped in a new t-stat, and im still seeing pretty hazy water/coolant. ive got no signs of oil in the coolant, or coolant in the oil. SO….my guess is that ive got a sealing issue w the HG allowing combustion gasses to enter the cooling system….overheating it.

    That said……what are your thoughts, and do you think its worth trying the kw block seal, or any other product?


    • Austin says:

      Yep….I just approved his updated reply, and I think I am correct. Most people AND mechanics jump the gun and wrongly blame the headgasket when they have not ruled out the simple things first. I would bet you probably have a restriction in your radiator causing your running hot issue. I would put my hand up and down on your radiator when the engine is hot and see if there is a definite colder zone towards the bottom where dirt and rust build up on the bottom. In most cases a NEW radiator is the cure. You did not mention any tell tale signs of a head gasket or internal problem.

  231. Brian says:

    Thanks Austin. I will take it by a mechanic to see what they will say. I did try to flush out the radiator again today, before I noticed that you replied, and the temperature gauge did not raise while I drove with the Peak Flush in the car. The bottle says that I need to leave it in the car for 3 to 6 hours and drive the car in normal driving conditions. I have not emptied the radiator yet, because I have not driven 3 hours yet, but after I have emptied the radiator, I will take it to a mechanic. Thanks.

  232. Brian says:

    Hey Austin, if you could let me know what to do about my 2000 Oldsmobile Intrigue 3.5L I would appreciate it. I do not want to go out and purchase a head gasket for the car if it is not needed or it could be fixed another way. Thanks for your help.

  233. Brian says:

    Hello Austin. I have a 2000 Oldsmobile Intrigue with a 3.5L engine. A couple of days ago, it started to run hot and the temperature on the gauge went straight up to “H”. This is the first time this car has happened. I looked into the coolant reservoir, and the coolant looked like chocolate milk. I have changed the thermostat and used Peak Radiator Flush, emptied the coolant that was in the car, and put Peak Anti-Freeze into the car. The car still runs hot. After driving the car for two miles, the temperature starts to go up until it reaches “H”. When I bring the car back home, I look at the coolant reservoir and the coolant is bubbling. When the car cools down, I take off the cap of the coolant reservoir and the coolant level has dropped. Some mechanics told me it was maybe the head gasket. I was wondering what you think might be the problem? Would the K&W Engine Block Sealer help me out?

    • Austin says:

      You need to see a mechanic, do not do anything else yourself you will just be spending money. I would check the electric radiator cooling fan, check the radiator for a restriction and do a pressure test of the cooling system for a leak. You did not mention anything that would lead me to believe you have a head gasket problem. Rule out the easy stuff first. I would not be surprised to see a restricted radiator in a 10 year old vehicle.

  234. Renee says:

    Hi Austin,

    My boyfriend has a 1997 Oldsmobile Aurora and recently it has been running hot. He found out that he had a leak so he used a sealant (dont know what kind sorry!) to stop it and now he has no heat. What causes the heat to go out and can it be repaired.

    • Austin says:

      Lack of coolant in the system or coolant that is not hot enough is my first thought. Make sure the radiator is completely full of coolant. I would also make sure both heater hoses are hot under the hood, the thermostat might need to be replaced if the hoses are not hot.

  235. Amanda says:

    Hello! I hope you will be able to help me and get some input on what you possibly think here! I bought a 1999 Hyundai Tiburon from my mechanic…. When driven longer distances the car seems to overheat when I getoff the freeway and idle any…. We replaced the thermostat twice, replaced the temp gauge sensor, as well as installed a new fan sensor, the mechanic I bought it from removed the thermostat telling me it would be fine blah blah….. still ran hot…. I replaced the radiator…. still ran hot… was adding fluid to the radiator almost everyday…. did a compression test, which seemed to clear alot of air in the system! filled it completly up, ran hot again! also, when he changed the radiator, I asked him to replace the thermostat! and he did not! on my way home the other day I noticed it jumped up hot again, immediatly pulled off, waited about 30 mins, filled the radiator, made it the rest of the way home! when I did this my resivoir blew out quite a bit of anti-freeze and it also sounded like it was bubbling! My mechanic is gonna go thru the whole thing on Monday! but did want to ask about this thermostat problem… another friend of mine told me it could over heat because the thermo stat is not in there and alot of the water would evaporate… therefore causeing it to run hot! is this true? and if I used this product and ran it 500 miles…. wouldnt it tend to run hot running it that long with just water and no coolant protection? I am very willing to try it… but a bit skeptical! any input would be of GREAT help! Thanks!

    • Austin says:

      I would be suspect of a faulty electric engine cooling fan or air in the system that needs to be bled out. Again I encourage you to get a cooling system pressure test to see if you have a coolant leak not a compression test which tests the internal engine condition.

  236. Patrick says:


    Did you mean to say that you “have not” used the new K&W product? Also, does K&W caution not to drive the car with the stuff you suggested in it?

    I’m wondering if they have the same warning on both products.


    • Austin says:

      Correct have not thanks for the correction. I use their older product and use it as I describe not as the directions state on the can, works best for me.

  237. Patrick says:

    Hey Austin-

    What are your thoughts on the other K&W Head Gasket Repair product, K&W NanoTechnology Permanent Head Gasket & Block Repair? It says on the label, in bold letters, not to drive car with the product installed. Does it say the same thing on the KW Block Sealer label? Anyway, just wondering if you have any experience with it?

  238. levi says:

    hi Austin,
    I am so sorry about all of replies, i am using a ps3 as a computer because mine is down right now and couldnt tell if any messages where being left, please forgive me for that, sir.
    i’ll have those things checked out, went to a pontiac dealer everyone says take to dealer that had oldsmobile before they closed down found a couple and will let you know what happened.
    Thank you very much Austin, you have been a great service to me, i know what to ask and what doesn’t sound right with what they are saying. Thanks again.

  239. Aaron says:

    I have a 1996 Chrysler Cirrus V-6 and it just blew the head gasket. I noticed your article while researching my options since repair will more than the car is worth. My question is since I’m not mechanically inclined (lol) how difficult is this fix? I saw the product you mentioned and do I remove the thermostat or just flush the system very well? I also saw a product that didn’t require this. You just add it to your radiator. I believe it’s by Bartol. Is this product sound? At wits end! Suggestions?

    • Austin says:

      Have a lube place do it for you then, drain out the antifteeze, add the can of K&W block sealer and drive the vehicle 500 or so collectively, not at once…..unless you want to. No need to remove thermostat. Caution, you will not have freeze or boil over protection, so keep an eye on your temp gauge.

  240. levi says:

    hi again Austin,
    replaced radiator and oem thermostat, had coolant system pressure tested again no interal/external leaks before any repairs, drove car for approximately 15 min without any problem let car idle for approximately 35 min without any problem. let car sit for approximately 2 hours.
    drove to work approximately 25 min later car ran hot, when the rpm’s over 3000 car returned to normal on the temperature gauge. it did spike a few times before that then came back down to normal temperature. got close to the red pulled over checked under the hood, there was anti-freeze that came out on the engine. when it cooled down i had to add anti-freeze, then i was able to get to work and on trip home it did the same thing. what else is there to do, any help is greatly appreciated.

    • Austin says:

      This STILL sounds to me like a low coolant level problem/lack of coolant circulation. If the temp gauge goes down when you rev the RPM’s up to 3,000 it would indicate to me that.

      1. There is a leak in the system and coolant has leaked out and is low
      2. There is not enough air volume being pulled through the radiator…bad fan clutch, restriction in radiator, something blocking airflow in front of radiator
      3. There is not enough coolant circulation in the system, restriction somewhere, and air pocket or bubble in the system, a water pump impeller that has corroded away and not pushing the coolant through the system fast enough.

      Some vehicles have a coolant “bleeder” screw near the thermostat housing which will help you bleed the system of air. If you have one, use it, if you don’t try running the engine with the radiator cap off awhile until all the air burps out. You should also have the heater ON, so the coolant fills the heater core inside the dash and pushes out any air pockets that might be there.

      When the engine is HOT, there should be lots of internal pressure on the radiator hoses and you should not be able to easily squeeze the upper radiator hose with your bare hand. If you can, you either have a coolant leak somewhere or you could have a faulty radiator cap.

  241. levi says:

    hi again Austin, replaced radiator and oem thermostat, had coolant system pressure tested again no interal/external leaks before any repairs, drove car for approximately 15 min without any problem let car idle for approximately 35 min without any problem let car sit for approximately 2 hours. drove to work approximately 25 min later car ran hot, when the rpm’s over 3000 car returned to normal on the temperature gauge.i am at a lost now, what else is there to do any help is greatly appreciated as i am getting low on money.

  242. levi says:

    Hello Austin,
    I had it checked out before I had the radiator changed because I did lose some coolant. Took it back to the dealer who did another coolant test (at least thats what they told me), it was still no external/internal leaks. I had the radiator changed out and I am going to change out the thermostat. Can you tell me how to bled the system for a 1999 oldsmobile intrigue with an 3.5 engine.
    The coolant in the reservior was boiling hot and I saw bubbles in the coolant. I was told that if I took off the reservior cap and have some one start the car and go to approx. 1500-2000 rpm’s that if I saw large bubbles then the head gasket is seeping or blown, I did this and did not see any bubbles in the coolant. A mechanic did it when the engine was hot and he told me that the head gasket was seeping because he saw bubbles and also, that he took off the reservior cap and the coolant spilled and it shouldnt because it’s not any pressure on it. Thanks Austin for all your help.

  243. levi says:

    Sorry it took so long to answer back, austin, work night. I am going to change the radiator tomorrow and let you know what happened. Thank you for answering my question.

  244. levi says:

    replaced water pump, thermostat, new reservoir cap, flushed and pressurized system, car still overheats when idling or driving, was told it might have air in it, lifted up on reservoir side still overheating. fans working, no coolant is going through engine. engine temperature was 246ยฐ, upper hose 112ยฐ, thermostat 90ยฐ, its no mix off oil\anti-freeze. was told it might have an pin hole in head gasket.
    dealer did coolant pressure test sept. 8, 2010 was told no interal/external leaks, it looks to them to be the thermostat, when i got there it also could be a restriction in the system, want $300 to find it, just brought it home. but now its misfiring went autozone and repair shop. they say this engine is a caddy’s v6 which is known for overheating. help please, thank you

  245. Daniel says:

    Gosh, I would like to have read this post before yesterday…
    I take mi sentra 2002 to the mechanic to change the headgasket, it cost me $700.

  246. jong says:

    okay i have a 300zx 1990 and puff of white smoke comes out of the exhaust when is warm. not cold.. when i get out of the car it has a sweet scent so i believe its the head gasket so i did the radiator pressure test.. and still believe its the gasket. i have tried your method today.. now i have to put 500miles into the car now.. crossing fingers!!

  247. tom pavey says:

    I have an engine head leak in my 1989 VW Vanagon Water cooled T3
    I would like to try using the KW sealant you mentioned, but I live in Australia where this product is not available. Is there some Auto Store that would do a Mail Order for me?



  248. Armando says:

    Hello to all.

    How/What does it mean to bypass the heater core? Thanks.

    • admin says:

      To cut the heater hoses off of the heater core under the hood and tie them together to make a loop, thus bypassing the heater core inside the dashboard and stopping a coolant leak on the passenger floor board.

  249. percy says:

    okay I purchased the K&W and i am following directions however when I removed the thermostat the water was leaking out what do i do also my car is missing badly since it overheated one or two of my cylinders is not firing could this be due to a blown head gasket

    • admin says:

      It was not nessacary to remove the thermostat. Please re-read my original article on how I suggest you use the sealer, not as described on the can. Hopefully you already had a cooling system pressure test to determine if you do in deed have an internal coolant leak like from a head gasket. You might have coolant in those cylinders hince the miss fire.

  250. Mark says:

    Concerning the recommendation to drive 500 miles with the sealer in the coolong system. Does that need to be done in one continous trip, or can that be done over a week with the engine off for periods of time?

  251. Woodrow says:


    Your K&W method has worked well in fixing an external coolant leak on a 2000 Subaru EJ251 head gasket. This leakage on the driver side of the engine has been a notorious and well-documented problem for these late 1990’s and early 2000’s engines.

    I drove for 1000 miles with the K&W because that was when I was sure the leak had stopped.

    Next I added the OEM Subaru Coolant, along with the required Subaru Cooling System Conditioner (additive) which is part of the recall “solution” for the leaky gasket problem.

    After completion, the first 1000-mile test trip was under grueling conditions of hot weather, stop and go, cold starts, etc. Upon return, I had lost only 2 oz. of coolant, but I wonder if some of that volume might have been air-release from the cooling system. Previous to the K&W fix, I was losing about 2 oz. every 30 miles.

    Many thanks,

    • admin says:

      Great update Woodrow. Hope you have a long term repair on your hands. You are probably correct about the air pocket in the system.

  252. JH says:

    ’97 Subaru Legacy, did the K&W treatment twice over the past year. The first one seemed to hold well throughout the winter, but driving up to elevation seems to push the system to overheating. Should mention I’m in southern Utah at ~ 5800 feet – longer trips can take the vehicle through varying elevations, when the coolant jets into the reservoir and boils out the cap. This also makes the check engine light comes on, but temperature gauge stays in the normal range. Short trips don’t seem to have an effect and the check engine light eventually turns off. Had a pressure test which showed no system leaks, replaced the cheap after market radiator cap as well as thermostat with OEM parts, which were physically more robust.

    Tried to address everything short of head gasket replacement. I think I can do a more thorough job of draining the coolant, but wondering if a third treatment would help or if there’s something else I’m overlooking. Appreciate any feedback and thanks for sharing your tips

    • admin says:

      I would be VERY suspect of a restricted radiator and would lean towards replacing the radiator. Flushing will NOT do anything, so dont waste your time.

  253. den says:

    I have a 2004 tractor 4 cyc diesel. blowing antifreeze out the overflow. no signs of antifreeze in oil. will k&w sealer work?

    • admin says:

      I have no personal experience with diesels at all, but the new Nanotechnology K&W sealer says it works for diesel as well as gas, so it would be worth a try.

  254. joe says:

    i have a 94 ford explorer ive pulled the heads and its apparent the head gasket was blown on each head the oil was a milk choclate color and there was no sign of coolant leakage in the cylinders my question is should i replace the heads and change the oil and add this kw repair stuff just in case the block cracked

    • admin says:

      If you have already pulled the heads, send them to a machine shop and get a valve job done, you will get a much better long term repair for not much more. I would not use the sealer since you have already removed the heads, just finish the job the right way.

  255. Nick says:

    I read where someone said they had a swishing sound of water from the dash area. I have heard that also on my car, I am currently trying the K&W method right now. What is that water swishing sound?

    • admin says:

      Probably air in the cooling system bubbling around in the heater core on the passenger dash area. As long as the radiator is full of water at all times I dont think I would worry about as long as the heater core is not leaking which would make the carpets on the passenger floor wet

  256. Walt says:

    admin, can you comment concerning the difference between the standard K&W sealer vs. the advanced K&W Head Gasket and Block Repair with NANOTECHNOLOGY? Have you any experience with the later?

  257. Jason D says:

    I also have a ’01 Pontiac Montana, and just recently discovered that my overheating issues are on account of a blown head gasket. Turns out it is blowing exhaust into my coolant system. So my question is,
    Will K&B work when the blow out is in the opposite direction?
    (IE..instead of water entering the oil, or exhaust, it is bringing exhaust into the coolant.)
    I discovered this when I noticed I couldn’t get the air bled out of the radiator after replacing it.Just watched it bubble in the overfill reservoir. Thanks for any ideas or knowledge in this area.

    • admin says:

      Yes, as long as you have had the cooling system pressure tested by a professional and they have concluded there is an internal engine coolant leak then yes, I would use the K&W sealer as I described in my original article. Keep us posted.

  258. Jason says:

    I have a 1996 Land Cruiser. It has given me coolingissues for a long time. Now it seems to be using about a half gallon of water every 50 or so miles. I used to get an anti freeze smell often but it seems I’ve added so much water its about all water. My SUV idles badly once warm and seems to fowl plugs #5 and #6. Sometimes it smokes white smoke badly. The dealership said it had a blown head gasket yet didn’t/couldn’t do a great deal of checking. I had another mechanic tell me later he didn’t feel it was the gasket. I’ve had a third tell me to use sodium silicate. My uncle gave me a can of the block seal and I am ready to try it. I am contemplating bypassing the heater cores. I have read the instructions as well as reading here to leave it in the cooling system longer. I was concerned with having this stuff in there long term causing possible blockage of my third radiator that has been on it? My oil isn’t milky. Any advice is greatly appreciated. The cost to do the head job on this 4.5 inline Toyota engine is very expensive and to find a replacement head could be very difficult and costly.

    • admin says:

      Jason, I have given all the advice I can in alllll the previous comments and my original post. Your vehicle is no different than everyone else’s. I would add K&W like I mentioned in my original article and cross your fingers.

  259. Zak says:

    I’m with you walt. Wondering if the KW with nanotechnology is also
    supposed to be used as instructed here. Hopefully works better as it costs more
    than twice as much as the regular stuff at $20!

  260. Walt says:

    Has anyone used the advanced K&W Head Gasket and Block Repair with NANOTECHNOLOGY? I have purchased a bottle of it to use on my 93 Mercury Topaz. My intentions are to let the liquid remain in the cooling system for approx. 500 mile just as others have done but I would like to hear from someone that has used this specific K&W Head Gasket and Block Repair with NANOTECHNOLOGY. I am concerned that most repairs where the sealant remained in the cooling system for 500 plus miles were the basic K&W product.

  261. Dennis says:

    Update – Sunday, Aug.8/2010

    My 2004 Honda Civic now has 600 kms on it since putting the engine coolant back in the system; In my earlier post I stated I drove the car 640kms with CarGo Seal-Up in it..Everything seems fine so far! Thanks for the great advice Admin!

  262. Sam says:

    Ok I have a question. I have a 2002 Nissan Sentra with 122,00 miles on it. The check engine light came on, I went and ran a code test. It said cylinder 3 misfire. So I changed the spark plugs, no luck. Then changed the coil pack and boot from cylinder 3 to cylinder 1 and cleared the code. When The light came on again, ran the code, again said cylinder 3 misfire. Had the cat converter checked, it was fine. Then a compression test, it was fine. Now to the coolant test. With the pump on it, after about 10 mins the pressure dropped jusrt a little, and we could see just a little bit of antifreeze in cylinder 3. That indicates a gasket leak and not a cracked head to me because it was so slow to leak into the cylinder. What say you? Try the K&W engine block sealer? The only time the car acts up at all is when it sits for several hours. Like overnight. Otherwise it runs ok.

    • admin says:

      I am not convinced you have a headgasket leak but you should not see coolant in the cylinder………but the sealer could be a good test and wont hurt anything, so yes try it as I described not as they say on the can. Coolant will show up on the end of the spark plug as a white powder, so I would check the plug in that cylinder against the other plugs to see if there is a difference. You could have a fuel injector problem leaking fuel into the cylinder with the engine off???? Smell your engine oil dipstick to see if you smell raw fuel, you should not.

  263. mike says:

    Austin, Mike here…I had another mechanic to pressure test the toyota camry (03) and he concluded that the heads gaskets were indeed leaking externally. What would be your recommendation?
    Since it is external, would the K&W block seal still work, or do I need to get the gaskets replaced? Any advice would be greatly appreciated.

    • admin says:

      Mike, I think I would try the K&W sealer and cross your fingers. I wont hurt anything and lets hope it corrects the problem. I am still NOT convinced the coolant leak is from a headgasket though.

  264. Steve says:

    I have a 2001 Montana that had a ‘blown head’ according to the shop mechanic that would cost between $4,000 to $4,800 (a DEATH sentence!!!!) to fix – much more than the van was worth in PERFECT shape! I always try to follow the mfg. directions, but with nothing to lose – I flushed all remaining coolant and tried the KW fix. I am now three weeks into the program, and ALL IS WELL. No overheating at all. I lost water coolant during the first week, but nothing since then! THANKYOU for saving us some serious money during some very tight times for my family!

  265. Mac says:

    Also I forgot to add that this is the 5.6l engine should I use 2 bottles?

  266. Mac says:

    I am purchasing a 1987 mb 560sl and hoping to drive it over a thousand miles home. The problem is it has a verified head gasket leak. It loses about 2 qts of oil per tank of gas. I have no problem replacing the head gasket once I get home but I would like to drive it back instead of hauling it(call me crazy). Do you think KB will work in this case? Do I leave it in for the duration of the trip (I have three days to make the trip and I will be going slowly and watching gauges like a hawk) or do I stop and flush, adding the 50/50 solution? I have no fear of being left on the side of the road, but would like to avoid it if possible. Thanks for your input, Mac

    • admin says:

      I dont think the headgasket sealer will do anything for your oil consumption. This is probably something inside the head, valve stem seals etc. etc. I think you are going to have to buy a case of oil and just keep it topped off until you can get home and do a valve job.

  267. Dennis says:

    Sunday, August 1/2010 — Wanted to share my experience thus far using CarGo Seal-Up..My car is a 2004 Honda Civic Si (Canadian) with the 1.7L Vtec. The car developed a slow head gasket leak where combustion gasses were pushing coolant out of the overflow, even when the temp gauge was showing normal or close to normal temps. Took it to a service center where they confirmed coolant in one of the cylinders using a borescope.

    I knew it was a small leak because it had been around 700kms since it had given us any temperature issues..A month earlier I had completed a head gasket job on our other car, and I cringed at the thought of having to do another one! So I picked up a bottle of Seal-Up. Flushed my cooling system out about 4 times, then filled with water and added the “juice”. I drove the car for 640kms (hit that mark today) and just finished flushing out the system again, this time adding the coolant.

    During the 600+kms, the car did not overheat or force any water out the overflow; however the level in the overflow did change from time to time, and I did add some water to the system after noticing the level in the radiator was down a small amount. I’m guessing there was some air in the system. So far I am pleased with the process, and I will do another update in a week or so of normal driving with coolant in the system.

  268. Mike says:

    Yes, it is the same guy who was told that there was not a blown head gasket, but after the temperature gauge “moved for them”, they supposedly pressure tested it. Not really sure of what’s going on, but have a mechanic coming to do all necessary tests and he too mentioned that the leak may be coming from the intake manifold or a heater hose….will definitely keep you posted as to the outcome. I am, to say the least, somewhat agrivated with what is happening. I do thank you for your input as it has been invaluable.

  269. Mike says:

    bad news on 03 Toyota camry, it is a blown head gasket. It is leaking out the back of the heads. Would you still use K&W block seal or I was told about a new seal treatment called K-seal. thanks for all your input and yes, I would rather you had been correct….1200-1500 to replace hq. thanks

    • admin says:

      Is this the same Mike who wrote me just two days ago and said the dealership checked it and there is no headgasket leak? Now you have a VISIBLE coolant leak from the back of the head? Come on, really? This just all of a sudden happened after two shops have looked at it for you and did the recommended pressure test…..nothing showed up until now???

      I have seen headgaskets leak externally, bur kinda rare. Did a qualified mechanic perform a cooling system pressure test? Are you absolutely sure this is not caused by an intake manifold gasket leak, a heater hose or something else? I am still not convinced.

  270. Mike says:

    Austin, back again….I carried my 2003 Toyota Camry to the dealership and they told me that the head gasket was okay, but my temperature needle continues to go up and then back to the midway point. I changed the thermostat and while it was at the dealership, the temp was fine. I truly am at wit’s end about what to do, any suggestions other than carry it back and let them keep it until it does the same with them. The service manager did mention a radiator cap. Could that be the culprit? I apologize for bothering you man, but I don’t have a clue as what to do….HELP IF YOU CAN, PLEASE!!!

    • admin says:

      Good news there is no internal coolant leak. ๐Ÿ™‚

      You will have some fluctuation of the temperature gauge as long as it is in the normal range I would not be too worried about it. If its out of the normal range, then we might have a problem.

      Few things come to mind. I would want to dig deeper to determine if the engine IS in fact running hot, or is this a gauge issue?

      1. The gauge is not getting the proper signal from the Temperature Sending Unit (not temperature sensor…different part). The sending unit screws into the engine and measures the coolant temperature and sends that info to the dash gauge. These parts dont usually fail often on Toyota, but could be a problem on yours. You can test the sender, but to be honest replacing it is cheaper and faster than testing it sometimes.

      2. When does the engine appear to be running hot? If at freeway speeds, then I would suspect a restriction in the radiator and radiator replacement is needed.

      3. If the engine appears to run hot at stops or idle speeds and with the A/C on, I would suspect you have a problem with the electric cooling fan motor up near the radiator.

      4. If you already replaced the radiator…..cant remember if you said you did or not. I would make triple sure you do not have an air pocket in the cooling system. Sometimes you have to “bleed” the system to get all the air bubbles out after a major part replacement. Best thing to do is visit your local fast lube place and ask them to make sure there are no air bubbles in your system.

      Hope this helps

  271. Jon says:

    Hey, I would appreciate some advice.

    Just got back from my mechanic. His son pressure tested my coolant system. He believes my 360 is leaking out of a freeze plug inbetween the block and tranny. He told me to try a bottle of ‘Barleak Heavy Duty Stop Leak.’ The black gooey kind, but not the aluminum or copper.

    Do you think I should give the KW a try?

    I’m getting a lot of conflicting advice, so I’m tentative. I discussed the problem with a friend who’s a mechanic at a Dodge dealership and he said, “never put any of that %$#@ in a coolant system.” I’ve also read on the net of horror stories and people strongly advicing against using coolant system sealant.

    • admin says:

      I would NOT use a sealer additive for a freeze plug leak. I recommend you replace the freeze plug, although the freeze plugs are IN the engine block not in between the block and transmission, so I am a little concerned your mechanic is lost.

  272. LilEngine says:

    Hey, I have been reading this thread for some time and I just wanted to report some success with trying your method. So, first things first, my car didn’t fail a compression test, though I feel like sometimes cars don’t always do this? My mechanic said that sometimes it takes longer than half an hour for the compression to completely go. Well my story and I will try to keep it short is that my Nissan Sentra 2002,76000 miles, that I just bought has been giving me starting problems from almost the word go.

    It was flooding itself on a regular basis and no one could figure it out. My friend/mechanic said compression was ok. Always started right up if left only a few minutes but longer than that, it was hard if not impossible Then it just started to get worse. Eventually it was always flooding itself and white plumes of smoke would come from the exhaust at startup and it would idle rough for a few seconds (also I have to mention sound of swishing liquid under the dash??) The clincher was when it overheated one day and we discovered all the coolant had leaked out (though it wasn’t a really fast leak). I did some looking on the web and decided I would try your method since I can’t afford the headgasket repair right now.

    My mechanic drained all my coolant and flushed it and then we put the K and W stuff in. It’s still in the car right now and I’m at 600 miles. Ok, so it has not flooded since the day I put it in! I took in on the highway for 2 hours the day I put it in. The next day, the car started with no problems. I have not flooded the car since. White smoke is gone, no coolant leakage and swishing sound from under the dash is gone (what the heck is that?). The car is driving. I can take it anywhere and know it will start no matter how long it sits.

    I do have a question about if it’s better to leave it in even longer? And also it’s brutal hot summer weather right now and I was wondering if I should wait for it to cool a little before draining the sealer. Just to ensure that it seals properly? Thank god for this site and your advice because I’m sure I’d be stuck in the garage still otherwise!( I should add my mechanic had to ground a wire to the coolant sensor too because that was malfunctioning and causing the car to flood. but even after this was fixed the car kept flooding itself)

    • admin says:

      Great news, thanks for the update. You are correct that a compression test can sometimes not show troubles. That is why I highly recommend a cooling system PRESSURE test. They will take a bicycle pump basically and screw it on to your radiator cap and fill the cooling system with air which will push out the coolant where the leak is making it easier to pin point leaks.

      I would drain out the sealer and go back to a 50/50 coolant mix and pray real hard. ๐Ÿ™‚

      The copper flakes in the sealer will create a permanent seal if things work correctly. If not, you MIGHT have to do things over again, but by the report you give I would suspect success.

  273. Mike says:

    Austin, I’m sorry that you understood me to say that I was gonna go ahead and use K&W (only if it was indeed that)…I have changed the thermostat and I am getting an overflow from my reservoir when I am driving but not when it is idling. I am headed to the dealership to have it professionally inspected. I do pray that you are right about the head gasket, as there have been none of the usual symptoms, except the check engine light. Thank you very much for your imput, it is greatly appreciated.

  274. Mike says:

    Austin, I chatted with you last week about a 2003 Toyota camry with a heating problem. You suggested that I have a cooling system pressure test done as well as check my spark plugs and/or wires for the misfire diagnosis on cylinder #3. If it is indeed internal, i.e., blown head gasket, would you recommend the K&W block seal solution for the car????

    • admin says:

      Yes I would recommend K&W IF you are absolutely sure you have an internal coolant leak like from a head gasket failure. I am still not convinced you have a head gasket issue… prove me wrong. ๐Ÿ™‚

  275. nick says:

    I made a mistake, actually I haven’t changed it since right after I put in the sealer. It looks fine but has little redish looking particles sometimes, I thinks it’s what little of the sealer that got through before it stopped the leak. It isn’t milkshakey anymore at all, and no white foam on cap after driving it. Also is the little bit of water loss normal because the water gets so hot little comes out the cap as steam?

    • admin says:

      Water loss COULD be normal from your high temperature. I would continue until you get the 500 miles or so and then go back to the normal coolant mixture and cross your fingers

  276. nick says:

    Las Vegas, NV
    1996 Nissan Maxima

    I have a question about the details while using this. I am currently using the K&W and have driven 425 miles with it so far. I’m guessing it’s normal to lose a little water throughout this process due to heat, I live in Las Vegas and it’s been over 100 degrees every day since I put this in. I am not losing much, a lot less than when the coolant was going into the oil before I started this method. Also I changed the oil after I put in the block sealant and 250 miles later too. What do you recomend about the oil changing during the process? The stuff is working though and it’s so awesome!

    • admin says:

      if the engine oil is milky and looks like a chocolate milkshake then you should change it if it looks like normal oil I would wait until you have proven the sealer has permenantly sealed the leak

  277. Paul says:

    I have 1993 ford explorer sport that recently has seen overheating issues.A radiator mechanic put a dye tester over the radiator to detect gases within the coolant…it turned yellow which he stated was a “definite” head gasket problem even tho I’m not getting the white smoke out of the tail pipe nor is my oil looking especially corroded.Should I take his advice for face truck has nearly 180,000 miles on it and $1100 to fix the gaskets is nearly similar to the $1300 for a replacement engine.BTW would this block sealer be a viable option?BTW I was told that the gasket repair IS NOT the cure all,as mechanics have stated to me they fixed the head gaskets only to have the car start smoking profusely from lower engine defects,and i definitely dnt have the money to throw awy on such an expensive job.I only need to make it in this vehicle for at least 2-3 months then I can get brand new engine…I just dont wanna destroy the vehicle before that time.

    • admin says:

      If you get a cooling system pressure test and they conclude there is an internal coolant leak then yes try the sealer as I describe in my article. If the pressure test shows no leaks….then I would do nothing. If you have an overheating then get a better mechanic to diagnose the problem for you.

  278. vince corrado says:

    I have a 90 jeep cherokee radiator was replaced with a new one new water pump installed new thermostat new radiator cap new freeze plugs clutch fan is good electric fan is working it runs cool on the city streets 190-210 (normal from what i know for a jeep with the older cooling system) it also runs at 210 fine on the fwy at fwy speeds but as soon as I start giong up hill it gets hot it does sputter a little and lose power right before it overheats there is no oil in the coolant from what i can see no water in oil and i have not seen white smoke out the tailpipe or excessive water other than normal condisation in the morning I’m freaking out I think there is a head gasket problem or a tiny crack in the block that opens up from the cylinder and is both or either compressing or sending heated gas into the coolant system I purchased a can of K&W and im going to flush the coolant out and try it I’m on a extreme budget cant afford a mechanic to pressure check it but from what i have heard i have a blown head gasket or cracked block I dont see any coolant dripping anywhere HELP! broke and desperate for a fix thank you

    • admin says:

      I dont think you have a head gasket issue so hold off on the sealer for now. I would be suspect of your ignition timing being advanced too high….do you hear any “pinging’ or clattering in the engine when you go up a hill or on heavy acceleration? I would have your mechanic check your distributor and base ignition timing.

      Second thought would be you have a restriction in your catalytic converter, causing too much exhaust back pressure which will cause lack of power and overheating. Any exhaust shop can test to see if you have an exhaust restriction.

      Third thought would be a restriction in your oil pump. If there is not enough oil pressure (caused by a restriction in the oil pump screen at the bottom of the oil pan) there will lack of power, overheating, engine clatter etc.

      I think you have a mechanical problem, not a cooling system problem…….unless there is a restriction somewhere in the cooling system like a collapsed radiator hose or kinked radiator hose but I would bet you have already replaced them or inspected them.

      Let us know what you find out.

  279. Mike says:

    I recently purchased an 03 Toyota Camry (2.4). As I was driving the temp gauge quickly moved from mid-point to hot, bu quickly returned to mid-point. It did this several times. I had a mechanic check it and the water was low. He added about 2/3 gallon and the car ran at mid-point for several days. Last evening, the gauge did the same thing as the first day (only once). It returned to mid-point. Also the check engine light came on and revealed a misfire on cyl. #3. The mechanic decided to do a compression check with the following results. Cyl #1 and 2 had a compression of 165, while #3 was 149 and #4 was 155. My question is, does this sound like a leaking head gasket and if so, will the above mentioned seal block be effective as it appears to be a small leak?

    • admin says:

      I would get a cooling system pressure test first before you do anything. Hopefully you have a simple to repair EXTERNAL coolant leak or a problem with the electric cooling fan or a restriction in the radiator and not an INTERNAL leak from a head gasket etc. Those compression numbers should be fine, so I dont suspect a huge problem. I would probably be more inclinded to suspect worn out spark plugs or plug wires and an external coolant leak. You probably have 2 problems. Get them repaired ASAP so you dont have a 3rd. ๐Ÿ™‚

  280. Bobby says:

    I’ve seen all the post on using K&W Block sealer. I am thinking of using this on my 2004 yukon. I have a problem with lost of antifreeze from the engine but have no signs of any leakage from the engine nor do I smell any thing from the exhaust. The oil is clean with no signs of antifreeze. I did find a GM TSB that reference this exact problem. TSB 06-06-01-019B dated June 12, 2007. It seems that there is a casting problems with the heads made by a company by the name of Castech. Seems that there is a porosity condition with the casting that can develop cracks. My question to you is, is there a chance that this product could clog up my heater core or radiator. I plan on following your direction on leaving it in for at least 500 miles before I remove it. Your thoughts would be greatly appreciated thanks

  281. elite25 says:

    i over heated my honda civic but turned it off right after i noticed it was running hot it was then blowing out white smoke when i give it gas and doesnt wanna crank up easy so i let them do a pressure test and they said one cylinder has low compression now also and said it failed the chemical test they want 800 for head gasket job so i will try that block sealer and let you know if it works for me

  282. Hitman3 says:

    I have a 92 Cadillac Seville 4.9 with about 165,000. Bought it about 4 months ago from a private party. It has been overheating for the last month. I replaced the thermostat, radiator cap, upper & lower radiator hoses and radiator. The car still overheats. Yesterday it shut off completely. There is carbon build up in the pipes, intermittent white smoke from pipes, no visible leaking of coolant/water from anywhere. Have to add water every 2 days. I can smell coolant and slight odor of gas. When car overheats the temp guage fluctuates and the overflow tank will bubble. The car idles rough and rough on the take off…it did pass smog and a recent FULL tune-up was done. I was going to use a product called “blue devil head gasket sealant” because I belive its the head gasket. My questions are:
    1. Does it sound like the head gasket?
    2. Is this product safe or advisable?

    Repairing the head gasket is not an option…the car is old and I don’t have the money and I have another vehicle anyhow. Thanks for any input.

    • admin says:

      Get a cooling system pressure test then a compression test first before you do anything. If you fail either of those, then you might want to try the sealer, although I have never heard of the sealer you mentioned. I have had great success with K&W as I mentioned.

  283. mike says:

    after a pressure test it is a headgasket problem. Car has 165000 miles on it. I did your step by step fix and have no problems. I will be trading the car in so this fix will help get me more money. Thanks for your help

  284. Christian says:

    I have a 2001 Aztek w/ 173,000 miles. It overheated as I was driving to another city. I pulled over thinking it needed coolant bec. I have to add coolant every month. However, this time the reservior was completly full. I took the rad cap off and the coolant drained out of the reservior. I was able to get it home (with the temp. gauge beeping at me) and the mechanic didn’t look at it but said it was a blown head gasket. The Aztec isn’t worth the $1200 to fix it, but was wondering if the engine block sealer would work?

    • admin says:

      Get another mechanic and have them perform a cooling system pressure test FIRST like I mention 100’s of times in this article thread. If a mechanic ever tells you you need a headgasket replacement without doing a cooling system pressure test first…..RUN! If you have had a coolant leak for and had to add coolant for months….shame on you ๐Ÿ™‚ get this professionally looked at and a pressure test done then we can talk about options IF you really do have an internal leak…..which I am betting you do not. External coolant leak, yes, most likely. The Block sealer I talk about is a great option as a last resort and is what I recommend to people who have proven they really do have a head gasket leak and doing the job correctly would not be cost effective.

  285. Nick says:

    Have a 97 ford explorer thermostat went out and housing had hole in it i wanted to know how long does this k&w last just in case of any internal problems with cooling system

    • admin says:

      Its a permanent seal, but you have not given me a good enough reason as to why you need to use it. Those thermostat housings are cheap aluminum and I would bet you had worn out dirty coolant in the system….and the coolant is what protects the metals of the engine. Hopefully this is the only damage.

  286. Carrie says:

    Thank you for your help also this car has The cooling system that does not use a radiator cap on the radiator but on a remote tank. This tank was replace so the cap is new..The hose you mention doesnt swell. I checked cooling fan it finally kicked on around 215-220. Im in process now looking for a radiator im hoping that is what is causing all this.I really hope I havent damaged the engine due to it getting so hot.Thanks for all your help,Carrie

  287. Carrie says:

    I have a 99 grand am gt 148,000 miles 3 months ago had to replace reservoir due to while driving it smelled antifreeze raised hood had cracked in tank.. Last week all of a sudden temp. went way in the red engine shut off raised hood to once again reservoir cracked…What is causing this? I changed the thermostat and put new reservoir on temp. is good but as I reved the motor up noticed antifreeze going up and down in the reservoir tank.Could I have blown head gasket?No white smoke but scared to drive it because something is causing the antifeeze to be pushed out the reservoir tank instead of into the radiator…Thanks for your help,Carrie

    • admin says:

      you have not really given me enough information to jump to a head gasket conclusion yet, I would be more concerned with a faulty radiator cap not allowing the cooling system to regulate internal pressure. A tell tell sign that you have a bad radiator cap is the upper radiator hose will swell significantly in size. You will see some movement inside the overflow tank, which could be perfectly normal unless the engine IS overheating and the system is boiling over into the tank. I would look hard at the radiator itself and make sure it is not clogged or restricted, check the electric cooling fan motor near the radiator to make sure it is working properly.

      Since you did mention that the temp gauge did register a running hot condition I would treat this situation as just that… overheating engine and begin my testing with a cooling system pressure test to make sure there are no internal or external coolant leaks, then test the radiator and cooling fan as I mentioned. IF this engine continues to overheat you could have a future costly head gasket replacement issue but hopefully that has not happened yet.

  288. Tracie says:

    I have a 2001 Mitsubishi Eclipse GT with 216,000 miles. No major problems so far, just routine maintenance. Lately I noticed my floor on the driver side is soaking wet so much that it leaves a big enough puddle to soak a large towel. It has also been overheating and when I fill the radiator with at least a gallon of water and fill the over flow tank it is gone with in a matter of a few miles and steaming horribly. My husband got the pleasure of replacing the heater core but there is still water on the floor and the radiator/over flow tank is empty and the car will over heat. We also had the thermostat replaced. Would the k&w block sealer be an option here?

    • admin says:

      Sounds like you have a stopped up A/C evaporator drain and that is cold and clear a/c water on the floor. I usually take my compressed air air hose and blow air inside the a/c drain hole located under the vehicle on the passenger side. I would bet you have a handful of leaves stopped up inside the A/C evaporator case inside the dashboard.

      if you have steam under the hood, you have an EXTERNAL coolant leak, like a radiator hose, water pump or radiator or something along those lines. Getting a cooling system pressure test should be first on the list, then once you know what is leaking….you can fix it. ๐Ÿ™‚

  289. mike says:

    Have a 2001 civic that just last night started to run hot. getting it pressure tested as I write. My mechanic has said he thinks it may be an internal problem since the check engine light code said cooloing system problem and he sees no external leaks. I did not get any white smoke from exaust,the overflow tank did boil over. If it is a head gasket should i just have it replaced?

    • admin says:

      I would get a second a opinion from another mechanic FIRST and if they come to the same conclusion that an internal leak is the culprit then I would suggest you try the head gasket sealer I mention….and I mention on the page. I would be suspect of a clogged radiator if the overheating seems to occur more at high speeds and suspect of a bad electric cooling fan motor if the overheating happens more at stops, slow speed or with the A/C on. Both scenarios would not show up on a pressure test.

  290. brian says:

    On a related issue, my wife’s 97 caravan had a heavy coolant leak coming from near the firewall somewhere. She took it in and was told it had a blown head gasket and $1200 repair. Car is too old for that big of a repair so I put a couple jugs of water in the back and told her to always fill the reservoir before she drove it the 6 miles to and from work while we looked for another car. Every day for about a week the water would drain out completely but one day it just quit draining. There is not a drop on the driveway and everything seems fine. There is no white smoke and the oil looks good. Now I don’t believe it was the head gasket but have no idea what it could be. Have you ever heard of anything like this happening? I’ve never had a leak seal itself like that. Any ideas?

    • admin says:

      This could be something as simple as a leaking heater hose which is located in the area you describe. I would FIRST and ALWAYS get a cooling system pressure test which would help locate the leak, either internally as a head gasket or externally as a heater hose or some other component. Find another mechanic and get the pressure test.

  291. travis says:

    ok, i definitely will. thank you for the advice

  292. travis says:

    ok, thank you. is it possible for a leaking head gasket to sound anything like an exhaust leak? the noise is coming from between the engine and the firewall right underneath the intake. where the head gasket is as well as the manifold. i was thinking maybe the reason he never fixed the manifold gasket was because he broke a bolt off or something and thought he could make some extra money off of me by saying it was a head gasket. all i know is ive read quite a few pages on head gaskets and its not really showing any of the same symptoms.

    • admin says:

      My gut tells me he probably broke off a bolt inside the cylinder head and has to take the cylinder head off to remove the bolt be broke off… in theory he is correct, you need a new head gasket….but only because he broke off the bolt and has to remove the head to gain access to it.

      In his defense….why I dont know….this happens, has happened to me….bolts get very hot in the manifold area and rust easily. When you try to loosen them, they shear off, in this case in a bad place. He should have warned you of this possibility, I know I would have. BUT, if this happened in my shop I would expect you to pay for the repairs that are now needed but then again I would have warned you before we started work.

      Maybe you can work a deal with him. Guilt him into working for half his labor charge and you supply the parts so there is no additional labor charge. I would also recommend you spend an additional $150 and send the cylinder head to a machine shop and have them do a complete valve job as well as repair the broken bolt. You will get a much better job in the long run.

      I typical valve job/head gasket on this vehicle could cost you $1200-1800 +- once you add up all the goodies that go with the repair, coolant, spark plugs, oil change, thermostat as a precaution, head gasket set etc.

      good luck and keep us posted will ya

  293. travis says:

    it doesnt run the smoothest either and it sounds horrible

    • admin says:

      If you have an exhaust leak up near the engine area, it will sound loud and might sound “rough” as well. Hopefully this is something simple or due to the faulty installation of the flex pipe. Here hoping anyway.

  294. travis says:

    i recently bought a 95 sebring lxi, i took it to the shop to get the exhaust fixed (it didnt really sound too bad but you could hear it). the mechanic said the manifold gasket and the flex tube were leaking so i left it overnight to be fixed. when i picked it up the next day he told me he had only fixed the flex tube and that i had a “leaking head gasket”. when i started the car it sounded 10 times worse than when i had dropped it off, but i have no smoke, and it is not overheating (i drove it around for a while to make sure). do you have any ideas or suggestions for me, as i am stumped and dont have the $600+ they are asking, or another car to drive.
    thanks in advance

    • admin says:

      I think I would get a muffler shop to inspect this noise for you before you shell out any more time and money. I would suspect you might need a new exhaust manifold….or at least now, thanks to the mechanic messing with it, and not a head gasket. Hopefully they have installed the flex pipe incorrectly or something along those lines and will be fixed under their warranty.

  295. Sue says:

    Ok, thank you. I’d thought you were referring to the prestone rust/corrosion cleaner, didn’t realize you were meaning the ‘steel seal’ stuff.

    As there IS the prestone corrosion cleaner (not the 10 min flush, but the 3 to 6 hr corrosion cleaner stuff) in the water (no antifreeze) already, and assuming some of that is now in the oil… is that going to be a problem with the K&W?

    Does the bubbling/boiling into the coolant overflow container mean that there is exhaust gasses getting into the coolant system? Or can it do that from other (possibly normal?) causes? The Overflow container wasn’t overflowing, but it was bubbling/boiling when the vehicle was running at temperature. Never having looked into the overflow before while a vehicle was at operating temps, I’ve no idea if that’s normal or clearly indicative of exhaust gasses getting into the coolant?

    • admin says:

      Engine is probably just running hot as to the overflow boiling over

      pressure test!

      Flush out the system and follow my directions as lists in the original article

  296. Sue says:

    admin says:
    July 3, 2010 at 8:36 am

    I would be a little suspect of a โ€œblownโ€ headgasket caused by your past overheating and would recommend you get a cooling system pressure test to confirm an internal coolant leak and no more external coolant leaks

    yes the k&w block sealer would be a great option here but stay clear of the additive you mention

    keep us posted

    I’m not sure if this admin post was in reply to me or someone else? If me, note that after the car was operating at temp for a bit, there WAS a watery oily leak onto the pavement. It doesn’t appear to be coming from the hoses, water pump, radiator or anything that way, however. I’m not sure just what its coming from yet.

    Also, you state I should stay clear of the additive – I’m not sure what you mean here. I’d added the coolant cleaner to get corrosion out of the block before realizing I had this problem – I’m not sure what to do about that now or what you meant I should do when you said to steer clear of it??

    • admin says:

      yes it was for you. get a cooling system pressure test to determine if there are more external leaks, and to be certain there is an internal coolant leak before proceeding with K&W sealer option. YOU said you are not sure if there is still leak or not, be sure and not guess if there is still a leak or not.

      YOU mentioned this sealer โ€œsteel sealโ€, and I would stay clear of using such products.

  297. Sue says:

    I guess there’s yet another one called thermagasket too? I wonder if there is any substantial difference between the three… and didn’t someone in the comment section mention a Barr’s version also?

  298. Sue says:

    94 Ford Taurus GL 3.0L 144K miles – car began making a rattling/knocking sound whenever I was on the gas, but either stopped or was quiet enough that I couldn’t hear it when off the gas and just coasting. The noise was almost as if the car was a diesel rather than gas… that’s the best I know how to describe it. I was only a mile or so from home and decided to try to make it home. No engine warning lights were on, temp was totally normal too (mid range on gauge). Got to a spot where I had to stop briefly before turning, and engine almost died but gave it gas and it kept running. Got a block further, and then the engine just cut out.

    I let it sit over night. Checked the oil on the dipstick and it looked normal (no metal flakes/chips in it, or anything else). Started car just fine, and it sounded NORMAL, not the knocking/rattling/diesel sound. Drove it the block home.

    Once home, discovered I’d had huge coolant loss – added over 2 gallons of water (engine supposedly takes 11 qts). I assume engine overheated causing the noise and then the engine dying – but do NOT understand why I ever got any warning lights and the temperature gauge read normal.

    Anyone know how that could happen or have thoughts on that?

    Anyhow – the water pump was leaking from the weep hole, so I replaced it. STILL had large coolant leak. Let a shop next door find the leak and they pressure tested to find it (unnecessary, leaked as soon as engine was on and for a few minutes after off). Anyhow, discovered that it was from the ‘heater tube assembly’ that feeds the heater core. Heater core had gone bad several years ago and I’d just bypassed it because replacement would take removing entire dash & supposedly evacuating AC also… So I jury rigged hoses to go from the water pump bypass hose and bypass the entire set of tubing.

    Whereupon I discovered that they overpressurized or radiator was about to go anyhow, because now I had a leaky radiator. Replaced the radiator. Ran car just a couple of minutes to check for leaks, no leaks. WHEW. Drained out a little water, and put in some of the prestone coolant cleaner – its the stuff that you run with for 3 to 6 hours and it cleans out corrosion from the system.

    Then ran car for about 20 min with hood up, just still checking for any leaks and letting the cleaner get started… at first was surprised that it only got to mid-range temp wise when the thermostat tripped and for a few min it ran between less than mid-range temp to spang on mid-range, then it seemed to shift and go a bit warmer, from mid-range up to a little higher but still nowhere near the top of the gauge or the red line area. Noticed, however, that there was some a little bit of smoke/steam coming from the engine compartment.

    Then also noticed that the radiator overflow container was bubbling/boiling – but have no idea if that was just normal filling as the engine heated up, or ???

    Then suddenly got a leak UNDER the car, a watery oil… from the passenger side of the vehicle sort of in line with the middle of the wheel.

    Turned the car off. During all of this the car sounded fine. When it had cooled just a little, pulled the oil dipstick and now the oil looks a little like coffee with a little creme in it, sort of opaque dirty tan color… its not foamy looking like an emulsion however, but I’m assuming this means I’ve got water in the oil? That the engine started running a little hotter once exhaust gasses and/or oil got mixed into the water/coolant system?

    That the original episode must have done serious damage, but somehow that didn’t appear until either the engine was at operating temps again and/or I had the coolant system fixed so it was pressurizing properly?

    Do these symptoms peg the problem, or are there multiple possibilities? Suggestions for how I can tell what the problem is or at least narrow it down, and if the K&W or something like it might help? I’ve also heard of another sealer called “steel seal” – and am wondering how the various products compare…

    • admin says:

      I would be a little suspect of a “blown” headgasket caused by your past overheating and would recommend you get a cooling system pressure test to confirm an internal coolant leak and no more external coolant leaks

      yes the k&w block sealer would be a great option here but stay clear of the additive you mention

      keep us posted

  299. Charles says:

    Hi, I just tried it with Bar’s Leaks and it’s working well so far. My number two cylinder in my ’77 F-150 with 351 M was getting coolant in it. The truck ran rough and produced a lot of white smoke upon start up. I figured I would try an additive, and the Bar’s Leaks was all they had at the local parts store at the time. I’m doing it as you recommended, and I couldn’t be happier. The engine runs smooth, cool, and I’m not losing anymore coolant! Thanks!

  300. Ansterdan Viana says:

    I will post my results as soon as the car is out of the mechanic, dont worry, i paid the mechanic to inspect the car bumper to bumber so he could just tell me if it is the head gasket before i use the K%W product. Ill keep you guys posted. Thanks a lot.

  301. Ansterdan Viana says:

    Thanks man, im going to try and thank you so much. I drive a volvo s80 and if this process works, you saved me $2,200.00. Thank you very much.

  302. Ansterdan Viana says:


    • admin says:

      Personally I have had much greater success with my instructions than that on the can. Have been doing it my way for many years, it was taught to me by my father and it works. I hope you had a qualified mechanic run some tests to be positive that you indeed have a headgasket or other INTERNAL coolant leak.

  303. Ansterdan Viana says:

    Hi, there is just one thing that i dont understand??? So when i use the K%W sealer for the first time, you said that i “will NOT have freeze or boil over(Overheating) Protection during the first 500 miles” – So that means that if i use this product now and follow your instructions, will my car still overheat for the first 500 miles since you said that i wont have protection??? will my car still get very hot even tho the sealer is in the system? I live in Miami Florida and it is very hot hot hot????

    • admin says:

      Without coolant in the engine you take a chance that the engine will run hot and possibly boil over. It’s hot in Florida right now so keep an eye on the temperature gauge and try not to sit in stop and go traffic to keep temperature down. Once you have driven the car awhile, roughly 500 miles in total you can drain the system and refill with coolant and water. Onthe flip side I you lived Ina snowy climate I would make sure the system does not freeze causing more internal troubles. Since he system is basically water you have to keep an eye on your temp gauge until you are ready to drain the product

  304. Phil says:

    I have ’95 Civic with 256k miles. Yes, it’s time for a new car. But until then…
    I’m finding oil in the coolant but no coolant in the oil.
    The car has been running ok but has recently started running hot. (I’m in Texas.)
    Will K&W work on this type of leak?

    • admin says:

      It COULD, but you need to get a cooling system pressure test first to determine if there really is coolant leaking internally and if it is, then yes K&W would be a great option for you. BUT, if there are no internal coolant leaks The overheating could be caused by something else though, like a clogged radiator, leaking waterpump or radiator hose etc. etc. and the pressure test will rule those things out as well.

  305. Jay says:

    K&W worked out for me. Used as directed by your site and saw the difference in minutes. Car started to run smooth and smoke/fluid disappreared from exhaust pipe. No overheating anymore and back to driving. Sure apprectiate all your information and Help! Take Care!!!

  306. Matthew says:

    Also, I haven’t run into any issues with overheating and it doesn’t seem like the engine runs or idles roughly (although usually when I first turn it on it seems to increase the idle RPMs from about 1000 to 2000 before dropping down on its own or if I rev it, they drop.) Before I take it, as I mentioned earlier, any thoughts on what the actual problem is and if it’s going to be worth the hassle? Thanks…

    • admin says:

      This vehicle probably has the large carburetor with tons of rubber vacuum hoses ……which is fairly notorious for idle and running issues when they get older. Again, I would not put any money into this vehicle but would learn to live with it or …….without it. ๐Ÿ™

  307. Matthew says:

    I’ve got an ’84 Honda Accord that has started smoking, but only after I get up to highway speeds or after the engine’s been running for a while. The smoke’s more of a gray than blue or white, and it’s not necessarily coming from the exhaust – and I’ve noticed that there’s oil in the air filter compartment as well as on top of the valve cover (I think.) From what I’ve read, it seems like it might be an issue with the PCV valve, but I’ve also noticed that there’s a hose on the top of the valve cover that seems to have corroded/come loose around the portion where it leads into the valve cover. If I take it in, would you suggest I point all this out to the mechanic or should I let them do their own thing?

    • admin says:

      This sounds more like an external oil leak to me than an internal coolant leak. With the age of the vehicle I would not be surprised to see a few oil leaks, and probably a little colored exhaust smoke every now and then just due to age and miles on this engine. You have not mentioned any serious symptoms so I would not be quick to throw money into this vehicle just because of a little smoke and oil leak. Oil in the pcv would indicate to me of some internal “blow by” in the cylinders and is probably from normal wear and tear of the internal engine parts. I would keep the engine full of clean oil and it would not hurt to use an oil additive like Wynns, or Restore both of which you can get at your local auto parts.

  308. tyler says:

    and it not at idle speeds it at an idle cuz if i am sitting at a stop light and it starts over heating i can rev the engine and it will cool down…

    • admin says:

      That could be low levels of coolant in the system that is causing that. When you rev the engine you speed up the water pump and force more coolant through the radiator which brings down the temp. You could also turn on the heater and it will bring down the temp as well. I am still suspecting a coolant leak, so go and have a mechanic Pressure Test the cooling system and lets rule out a leak somewhere. We are just guessing until you have proven there are no external coolant leaks.

  309. tyler says:

    but i can see the electric fans coming on… and it was a slight bit of smoke coming out of the exhaust but that is gone. and also for a little bit the 2nd cylinder was missing but that has stopped as well it is running good now, except for the over heating and having to put water in it weekly

  310. tyler says:

    ok so i have an 01 grand prix with a 3.1 l in it and it was over heating so i replaced the radiator, thermostat, water pump belt that went on water pump and all fluid, oh and rad cap…ill over heating i did the k&w nanotech via there instuctions and it worked for a week so i went back and i am trying it your way… but the car is still over heating while i am driving the 500 miles( only heats up while idling) and i have to put more water in the rad about ever week or so is this normal…

    • admin says:

      If it only overheats at idle speed I would be HIGHLY suspect of a electric Radiator cooling fan motor that is not working. You did not mention white exhaust smoke, engine missing etc. Of course you must get a cooling system pressure test first to rule out any internal or external leaks

  311. Tim says:

    I have a diesel tractor with oil leaking into the radiator. I have replaced the oil cooler. Would the block sealer work if the oil pressure is greater than the radiator? If not can I pressurize the radiator to a point greater than the oil pressure?

    • admin says:

      The sealer needs the heat from the cooling system and combustion chamber to “melt” the copper flakes and seal the leak. I dont THINK the sealer will seal your oil leak. I would seek a tractor mechanic and get their opinion.

  312. Johnna says:

    Thanks for clarifying!

  313. Johnna says:

    I’m sure this is a stupid question but I just want to make sure I understand correctly. You said you have had the best results with K&W but not with there instructions. On your steps you listed step #3 as “Add can of sealer to radiator and top off with water only”, do you mean to add the can of sealer straight to the radiator or mix with the water suggested on the can and then add to radiator. I greatly appreciate your help! Thanks!!

    • admin says:

      it would be a good idea to mix the sealer and water together in a bucket before you add to the radiator. Thanks for your email.

  314. Gary B says:

    I meant to say, I guess I need to have the system pressure tested right?

  315. Gary B says:

    I have had 2 mechanics check my problem but still unsure of the problem with any certainty. My truck overheated and I saw coolant coming from the water pump. Had it replaced. drove the truck about 200 miles and noticed the temperature getting high but did not overheat. 2 days later drove it about 150 miles, same thing, high but did not overheat. 2 days later drove about 50 miles and it overheated, the oil pressure briefly went to zero. Mechanic replaced the themostat. Truck begain overheating at shorter distances. Mechanic wanted to replace radiator. i took it to another mechanic who did the gas test and said that gases are getting into the coolant thererfore I have an internal leak. I tried K&W as directions said (b4 finding this site). No help. I notice that when I open the drain on the radiator some coolant drains, but I have to remove the lower hose for most of the coolant to drain. I don’t see any foam in the coolant resevoir and no steam or smoke coming out of the tailpipe. I’m wondering if I should go back and look at the radiator as the problem? any thoughts?

    • admin says:

      No we are getting somewhere. You have not mentioned any of the common symptoms of a head gasket issue, so I think we can probably rule that out for now. I would be highly suspect of a restriction in the radiator just from what you have told me. I would go back to the mechanic who leaned toward a radiator replacement and have him double check for leaks, cooling system pressure test again, and if there are NO internal or external leaks and the pressure test holds pressure…..I would probably start looking at the radiator as the culprit.

      And before you ask, no you can not FLUSH out the radiator to fix the problem, it will need to be replaced with an inexpensive after market radiator from your local auto parts store not the dealer. ๐Ÿ™‚

      Not sure if you read this or not, but might be helpful on my other website to determine which scenario of overheating you have and which direction you should begin to look.

      Engine Overheating

  316. Gary B says:

    Question, If the system is not drained and “cured”, at what point do you know it is fixed. Does it stop overheating during the 500 mile drive or after you have drained and refilled the radiator?

    • admin says:

      I repeat, I am not allowing the product to “cure” nor am I following the instructions on the can. I drain out the coolant from the system, add the sealer and top off the radiator with plain tap water then drive the vehicle about 500 miles or so. then drain out the radiator and as much of the system of water/sealer as you can then go back to the recommended coolant to water ratio in the radiator…usually about 50/50 depending on where you live.

      Important note! This product is designed to repair an internal coolant leak, either in the headgasket or engine block crack. it is not designed for overheating issued UNLESS the vehicle is overheating because of an internal coolant leak.

      Always always always get a cooling system pressure test FIRST to rule out any external leaks like from a radiator hose or water pump. if no external leaks are present and your mechanic suspects a headgasket failure, this sealer is a good option to try before spending tons of money to tear the engine down and replace the head gasket.

      Everyone understand?

      lots of incompetent mechanics will blame an overheating problem or coolant leak issue on the headgasket because they are too lazy to do a simple pressure test of the cooling system. I HATE guessing, it will always cost more money in the long and short runs.

      I want to educate you guys on what you should do FIRST not just try and sell you on the product as a guess. I do not get paid for the product or have any affiliation with them in anyway but the purpose of my site is to get you to get your mechanic to do his job properly in the first place……which is a pressure test!

      If you have used the product and had success….please comment for others to benefit from.


  317. Woodrow says:


    I am trying your K&W modified method on an external coolant leak (2000 Subaru EJ251 head gasket issue).

    However, could you clear up something? One step is omitted from you instructions, which is emphasized as very important by K&W:

    After 500 miles, when you drain the K&W and water mix, do you let the cooling system “breathe” for 24 hours?

    K&W states in all of their written material that this is critical, since only by exposure to air does the sealant complete it’s curing (hardening?). This makes sense because the major ingredient is sodium silicate, but perhaps the 500 miles of driving somehow compensates for this?

    Many thanks,

    • admin says:

      I have not done that…….I can tell you that I have great success doing it my way versus their instructions.

  318. Jeremy says:

    Few more tips I’d like to add for those who are not full time mechanics if I may:

    1) Have a qualified mechanic check out the car and make sure you do have a head gasket or block problem before you use block sealer. If the vehicle has seriously overheated, no amount of block sealer in the world is going to fix a head cracked through or a burnt piston/valve.

    2) Drain the coolant, then COMPLETELY FLUSH the system with water (cooling system detergent doesn’t hurt either) to remove all coolant, including running the heat to circulate through the heater core. Don’t and you can ruin your engine for good. This stuff is so good it will seal a 2 inch water outlet shut if misused.

    3) Thermostats are cheap. If you’re engine overheated, its always a good idea to change it out. Don’t let a 7-15 dollar part (sorry GM I-5/I-6 owners) ruin your day. Spark plugs are often fouled in these scenarios, and once again are relatively cheap and should NOT be overlooked. They should always be checked during the diagnostic process if an internal leak is suspected.

    4) It may be necessary to leave the spark plug out of an injured cylinder (disconnecting the injector, if possible, is also a good call) during the start of the sealing process. Cylinder pressure can make sealing an internal leak difficult. Don’t drive it around to seal if you do this.

    5) I think it needs to be clarified that driving the vehicle 500 miles is a good period of time for the sealer to work its way in things. However, it is no different to the engine than running it at a high idle (1500-2200 RPMs) for an hour or so. I would also point out that doing it in your driveway at a high idle doesn’t leave you stranded if things go wrong (in which case you should shut it off before anything is damaged). The only advantage to driving the vehicle is increased cooling by airflow over the radiator, but a garden hose and a little water nullify that advantage (on the rad, not the engine people).

    and finally:

    6) Draining out (no flush this time) and leaving the system open for 12-24 hours when you are done sealing is important as all the sealers I’ve used in the past have required time to cure once the seal is in place. The author of this page is absolutely correct about block sealer being a good and permanent fix for ailing engines, but 9/10 when block sealer fails to repair a leak it’s from improper use. Be thorough and know how to use the product to attack your specific problem before you use it! And enjoy getting out of an astronomical repair bill for under 30-50 dollars total.

  319. Mike says:

    I have a ’98 Saturn SL1 with a cracked head. This is a known problem with these cars. Everyone on the Saturn enthusiast website suggests that the head be replaced, along with a lot of other parts. It would cost me a minimum of 500 bucks to fix it. The car still runs great, but the oil is leaking into the antifreeze. This is because the oil pressure in the Saturn is higher than the coolant pressure. I believe that this is a good thing as no antifreeze is getting into the engine and damaging anything. Do you think that if I can flush out all of the milkshake looking antifreeze-oil mixture, that a can of K&W block seal would have a chance of fixing the problem?

  320. Jacob says:

    I have a 2001 Ford ZX2 because I am unemployed so I need a cheap fix. I have white smoke and what I believe is coolant comming out the tail pipe. Is This a blown header gasket? If so will the K&W Engine Block Seal work for me?

    Is there any special equipment needed to flush the system so I can do it my self? What will I need?

    Last I am reading that I need to replace the thermostat is this true? I just replaced my about a year ago and if I dont have to replace it, this would be great because every penny counts

    Thanks For Any Help You Can Give

    • admin says:

      Get an inexpensive cooling system pressure test FIRST, if you have an internal coolant leak like from a head gasket, yes the sealer would be a great option to try. You will need to figure out why the engine overheated in the first place which caused the headgasket failure or it will just happen again. Replacing a thermostat is recommended after an engine has over heated but get the source of the overheating figured out, and the headgasket leaked stopped first.

  321. mike says:

    I have a 2000 BMW 528i. All alluminum Block and Heads. I definitely warped my head. ( straight six), the does start NOW today, yesterday No start ALL DAY, and most of this morning, finally it started and then stalled out again, but it is NOW started like normal all the time….since 2pm today till now 11:00pm, I am assuming that my cylinders were saoked with anti-freeze, Hence the no-start. I know it’s blown, because I am blowing white smoke out the tailpipe, bubbling in the reservoir, and rough idle, it’s just obvious. So I am hoping I can pour in a can of K&W, and get back to “normal”, but my question/concern is will this work on an alluminum block with alluminum heads…???

    • admin says:

      BMW engines are another breed altogether and I am not very experienced with them….I tend to run away when a BMW comes to my shop they only cost me money and time since I am not experienced with them. According to the K&W manufacture there product states this. You have to find the source of the original overheating issue that caused the head gasket to fail in the first place or you are just spinning your wheels. I would HIGHLY recommend you get a cooling system pressure test first to determine if you really do have an internal coolant leak. I am not sure it will help a warped head, but the cost of a can of K&W is nothing compared to a valve job on this engine, which is what you will need to have done and have your cylinder heads inspected for cracks and resurfaced.

      Product Description
      K&W NanoTechnology Permanent Head Gasket & Block Repair uses nanoparticles that are one millionth the size of a millimeter. These particles fill in the crevices that other products cant, making a stronger, more solid bond thats permanently hardened to the surface area.

      Features and Benefits:
      # A permanent repair – Does not rely on cooling system pressure to maintain seal
      # Repairs head gaskets, cracked engine blocks, intake gaskets, cylinder heads, freeze plugs, heater cores and other cooling system leaks
      # Nanotechnology provides the tightest molecular bond
      # For gasoline or diesel engines
      # Treats 4, 6 or 8 cylinder engines
      # Works on aluminum, cast iron, copper, brass and plastics
      # Double your money back guarantee offered by manufacturer

  322. Bryan D says:

    So do I reinstall the thermostat right away or leave it out for the 500 miles? I assumed taking it out meant it could clog it up at the thermostat. Also a lot of people have been saying to bypass the heater core? I ended up blowing one of the heater core hoses and thats what started the problem in the first place. I replaced the both hoses and all leaks have stopped during the 30 minute idle.

    • admin says:

      no need to remove the thermostat or bypass the heater, but if you removed the thermostat, yes re-install it.

  323. Michelle says:

    When you say to drive the car for 500 miles does it need to be done in one trip or can it be broken down over multiple trips?

    • admin says:

      Just drive 500 +- miles in general before flushing out the K&W sealer and going back to a water and antifreeze mixture.

  324. daniel manning says:

    hi i live in australia and i saw k&w block sealer just asking where do u get it from so i can get some for my car i hope to hear from u soon many thanks daniel manning.

    • admin says:

      You should be able to order it from your local auto parts store…if they already dont have it on the shelf. You could probably buy it from ebay as well.

  325. Jay says:

    There is a chance my recent acquisitioned 84 camaro has a head gasket blown, I will be looking into it for more problems to point out if it is or not.
    if it IS then I would like to use the KW seal before changing out the gasket.
    My question/problem though, is this car is not fit to be driving around for 500 miles. It had been sitting for a few years and I just got the engine started yesterday. So without being able to drive it around 500 miles, how would I use this sealent?

    • admin says:

      You got me there my friend…..if it wont make it 500 miles for other reasons……is it worth spending money on this vehicle?

  326. Jim Garrettson says:

    After using the K-W sealant in the manner you described and refilling with the proper anti-freeze mix is it absolutely necessary to have the car in a heated garage at night during sub-freezing temps? It would be nice but I don’t have a garage.

  327. admin says:

    Guys look…..I have used this product on tons of vehicles in my shop, all makes, all sizes, all colors etc. etc. a few cars had coolant leaks that were too big to seal, but the vast majority were permanently repaired with the sealer and used like I suggested. MY suggestion is to try it, its cheap and you have no real other alternative other than replacing the headgaskets or engine.

  328. Kenneth Harper says:

    well i have a 98 camaro Stock … last Wednesday of last week i was taking my dad to auto zone of all places … keep that in mind .. i got out of my car and notices steam or something coming from under my hood …. it looked like smoke in a small area from what would be the right side of my engine heads if you was standing in front of my car .. couldn’t really pin point where … it was too dark at that point and no real good flashlight smelled like oil … that reminded me a few days earlier i smelled something sweet im thinking anti freeze … i check the fluid levels and they all seemed ok oil was full after letting sit for about 20 minutes oil presser was about 55 .. coolant was a little low but still have a full over flow … and when i first started temp was around 210 but i was told by autozone that was around normal … well i left and took my day 2.7 miles down the road and dropped him off .. went to leave and my car stalled out … its a 5 speed he looked at me like i could drive it but i did nothing out of my normal driving practice .. it started right back and i left made it about a half mile from autozone and heard a knocking noise so i was gonna pull in and check … got in a turning lane at the light right in front of it and them my car was making that noise worse shuttered i looked down oil pressure dropped to 0 .. car died .. i didnt panic i just called someone to help me move it .. when i got it out of the road it was smoking horrible from all over … temp was up around 240 this time oil was a quart low and NO coolant at all … i got some 50/50 mix and put it in when it cooled down . topped off the oil and it started just fine … no smoke or anything other than the smell from befor … i decided to try to drive home .. which is 8 miles from their and had my help follow me . i made it about 100 feet and the oil pressure was only hitting 30 … the temp was getting close back to 210 turned my heat on and cold air… made it to a red light and when it went back to idle speed it stalled out i got it started back … drove about 4 miles and it died going up a hill i couldnt give it enough gas to keep power at all …. temp was around 240 on my gauge .. and so i let it sit till i was down around 180 … tried to start my car and my battery was almost dead i had to jump it … got it started and kept driving made it about 1 mile befor i have a lot of sharp down hill curves back to back so i let off the gas and put it in neutral and it died going down hill temp was fine being a five speed i roll started it when i hit the bottom got about 2.5 miles from their going up another good hill and it shuttered and died again .. same thing as befor .. this time heavy smoke worse then it was the first time it died infront of autozone…. i was only a half mile from home and it was all down hill from their .. the road (and my car it seamed) went to start it again DEAD got a jump and made it home let it cool off and started checking again still no coolant at that point oil was low too..again i let it set even more got out my flood lamps and was gonan start trouble shooting things first i added water and spilled some so when i checked under my car for a leak i saw a few drops but i figured it was all draining off the frame i added more and then just fell down .. leak was viewable radiator … i took it out and added water to it and saww it had it fixed the next day…put it back in filled it up and everything seamed fine.. till about 20 minutes into it over heating bad … then shuttered and dies … never got into the red i called GM dealer and they said its a fail safe for the car to kill its self to prevent massive overheating damage … well it cooled down i added more 50/50 mix and it ran like a kitten after that … i thought i didnt get it full the first time .. next morning i got in it went to work same thing overheat .. let it cool and filled it up again .. kitten so i decided i had time im going to change the thermostat so i did tested it same thing got hot … cooled down topped it off and it was fine all night last night never getting above 185 .. and when i went ot work this morning it was a dream .. when i left work tho .. same old story so i let it cool and topped it off .. got home left my car running poped the hood everything seamed fine a little smoke was starting again right side head i had my nephew shut it off and i head my over flow bubbling and then i saw the coolant pouring out ov the overflow’s overflow soo i topped it 0ff again and let it idle all was fine shut it off same thing but it starts hard .. smokes from the head area and smokes or steams from the tail pipe for about 3 seconds when first started … oil pressure never get above 30 if that hi .. #3 cyclender miss fire .. and egr value codes are showing … culd this be a head gasket or block problem … and what do you think i should do

    • admin says:

      man o man, I would highly suggest you go see another mechanic and start from scratch….1. cooling system pressure test for a leak 2. compression test to see if the engine is ok…which is probably is 3. check spark plug wires and plugs to see if you just have an engine miss.

  329. Sha says:

    Ok we were told that our Cadillac Deville has a blown head gasket so we used the sealant as you instructed & before I could get 2 miles from the house the car started to run hot. Why do u think this happened? Should we have let it run on place longer before driving or what?

    • admin says:

      did you loose all the water in the radiator during those 2 miles??? If you DID, you have a large coolant leak somewhere….hopefully an external leak like a water pump or radiator hose and not an internal leak like a head gasket or internal engine damage. You might want to get a better mechanic to check this out for you before you do anything else.

  330. Jerry says:

    I tried the K&w today, and it Looks like it got into the Oil, on the dipstick, where before there was NO sign of coolant in the oil before. Now What??!! It also does NOT say drive 500 miles on the can I got! It just says add the k&w to 3 quarts of Hot tap Water, pour in the radiator (the 3 qt. mixture), then add water to top off the radiator, run engine for 20-30 minutes, then let cool, Drain,Let dry for 24 hours with cap off and drain plug open, then add Fresh Antifreeze mixture of 50/50. Again it does NOT say anywhere about driving 500 miles. I got the same stuff you guys are talking about. It was like $8.00 a can. Did someone along the line just throw in about the 500 mile thing? Let me know…Thanks!!!

    • admin says:

      Did you read my article?????? I have had the best luck with the sealer over the years using the product as I had described…not as stated on the can. Of course you are going to have the sealer showing up in up in the oil…you have an internal coolant leak!!! The sealer is not going to cause a head gasket leak. Re-read my article and try the additive as I described if you think you have an internal coolant leak.

  331. nick f says:

    i have a chevy aveo 2007 model cocked around 73400 kms my coolant keeps running low having to put in 1 litre of coolant water mix every two days since 3 days theres been water coming out my tail pipe with no white smokes no smell although when i opened the pressurized reserve tank and started up the car the coolant gushes out the authorized service dealer says i have a blown head gasket asks for a cost of $1100 .. well anyways my question is theres a drop in power n my fuel economy has taken a hit what are the possible damages if i run the car with a blown gasket… could this seal additive be used.. also have read in some forums that theses seals are a temporary remedy

  332. adam farmer says:

    and if i use kw or something should i change oil since it has water in it

  333. adam farmer says:

    i am looking at buying a 97 camaro has water in the oil and several people tell me its my headgaskets. is this true? and would it be easier to use steel seal kw or something like that or go ahead and get them replaced. i got a quote to do everything needed i supply parts 350 for labor. good price? im lost and in dire need of a vehicle money not to much of issue but dont wanna do payments

    • admin says:

      do NOT buy a car that has an internal coolant leak…..wayyyyy to risky!! Could easily turn into a $1500 job or a $3500 engine.

  334. Jenifer says:

    I recently purchased a 2000 BMW 740il, and have had nothing but problems with it. I fill the coolant, and it does not drain while the car is sitting there, but within 15 minutes of driving, it is completely empty and sizzling. The temperature gauge as I have seen it has only jumped into danger zone one time, the rest of the time it is halfway between hot and cold. The message I get on the dash says to check coolant levels. Any idea where the coolant is going if it isn’t draining under the car??

  335. Rob E. says:

    My 99 ford ranger pick up gets brown colored antifreeze due to rusting of the interior of the engine. A mechanic concluded there is small head gasket leak allowing combustible gases into my cooling system. Do you think K&W Engine Block Seal will work?

    One other factor to consider; the truck overheats when it sits at an idle. At 2,000 RPM’s the temperature goes back down into the safe range. I intially thought the overheating was caused by stuck thermostat or partially clogged radiator so I replaced them both but there’s been no change. Do you think the engine block seal will negatively impact the cooling system problem and any ideas what’s going on with that system? Seams like poor circulation but the water pump isn’t leaking.

    • admin says:

      I would check the fan clutch and or electric cooling fan if you have an electric fan. I would also make sure there are no coolant leaks, get a cooling system pressure test and make sure you have a good/new radiator cap. You did not mention any of the common head gasket symptoms, so I am guessing you have another issue and need a better mechanic.

  336. mlarr says:

    i have a 98 cadilac deville that is running through coolant and overheating after about 20 minuets. i dont uderstand how i can drain all the coolant and still not have any left on the walls of the lines and the motor and so on

    • admin says:

      Just drain out as much of the coolant as you can, there will be SOME left in the system…thats ok. Of course I HIGHLY recommend you get a cooling system pressure test first to see if you have a coolant leak that is external like a hose or water pump which the additive will have no effect on.

  337. VinCanFixIt says:

    Mom used to say “if all your friends jumped off a cliff would you?” Looks like I would after all. I’m game. I just got a free 92 Loyale (EA82/5spd) that was sitting under a tree next door since ’07. The former owner, a high tech aerospace engineer, had completed a full head gasket job including machine shop resurfacing only to have it billow steam all over the neighborhood. I had done this ten years ago and failed twice myself so I knew exactly how he felt.

    This time I had a lot more information at my finger tips thanks to the internet. I found out that Subaru installs as standard practice a propitiatory “coolant conditioner” which after further digging revealed itself as a quart of a really potent block sealer not available in the US. I found a quart in the UK on Ebay but they did not offer shipping to the US.

    I gave up and turned my attention to local solutions which eventually landed me with a quart of K&W Nano Technology and a few questions as to how to proceed. I thought I would take one for the team and give Admin’s KW-500 method a shot, this time using the new-and-improved Nano Technology sealer. It is too early to file a formal result but the instant results were spectacular. RPM’s up, quiet, no steam, no smoke…hose pressure ten minutes after shutting off the car. Impressive! See you in 500 miles.

  338. Paul says:

    My 99 camry has a crack in the radiator & a mechanic performed a liquid color test & says i have a blown head gasket.

    Should I replace the raditor & try the K & W block sealer?

  339. Noah says:

    if i used the k&w sealer for a head gasket repair will the slight loss of power return to my car?

  340. Ralph says:

    Will K&W work if air is leaking in the cooling system?

  341. Gary says:

    Hi, I recently bought a 97 Camaro (base model, not the anniversary series) and it is having a hard time cranking. The check engine light is on and after running a diagnostic test it showed the code for ‘random/multiple misfiring’. I changed 4 of the 6 spark plugs (as i could not reach nor see the 2 passenger rear plugs). The same day my water pump went out wich is no problem i cant fix, the problem i see is a orange (rusty) colored Gunk in the radaitor and the overflow resevoir when i drained the coolant system. After seeing this i got a little amount on my finger and it strongly resembles oil in its characteristics. Could this be a blown head gasket? I am not seeing any irregularity in my exhaust but i do smell coolant inside the vehicle when the A/C is on.

    • admin says:

      Pressure test the cooling system first before you do anything, that will let you know if you have a head gasket leak or some other internal coolant leak…..dont think you do though. Have the other plugs and wires replaced to see if your missfire goes away.

  342. Brett says:

    i am nearly positive i blew a head gasket yesterday, and i would love to try this method, but i think my car might have a more serious leak than this can fix.

    there is oil leaking somewhere around the head, and i have never seen anyone say their car was leaking oil from the gasket.

    also, what if there is anitfreeze in the cylinders? i know that is possible, and would the sealant work if this happens? i just dont want to mess up my forged internals by driving my car around trying to fix the leak. thank you for the help

  343. Samantha Coon says:

    My dad and i just put in a brand new heater core, and water pump because my car temperature would sky rocket and would over heat. We just checked the oil and there is water in the system, when yesterday there wasnt any. Do you think it would be fixable to put the k&w sealant in and it would be fixable?

    • admin says:

      Before you do anything else, get a cooling system pressure test to determine if there is an internal leak in the system, like from a head gasket leak. if you DO have a headgasket leak or some other internal engine leak the K&W sealer would be a great alternative to head gasket replacement.

  344. jeremy says:

    I dumped a bottle of k&w nanotech seal, lime green bottle fwiw, in a 90 chevy corisca which has a blown head gasket. I followed the dircetions, flushing the system until running clear water and dumping in rad. flush. The problem came when i let it idle for 20-30 mins, i could only get to about 5-10 minutes before the car started squirting steam/water out the overflow hose. While it did seal the leak and stop the white smoke, 3 days later its leaking again.

    Now the problem, this car is meant for a off road demo derby, meaning i can’t really drive it up/down the road for 500 miles. Should i retry the k/w seal and just drive it around the yard everyday for a half hour and see what happens? Its not like its a big lose if i blow it up, i could get more for scraping it out right now then i paid for it but would like to try and use it before junking it.

    • admin says:

      I think i would find the source of overheating….which to me it sounds like the engine is overheating maybe from a stopped up radiator or something other than the coolant leak? Fix the overheating problem then redo the additive.

  345. Brad Brueggeman says:

    I was hesitant about driving the 500 miles too. But, I figured with 233,000 miles on my truck I didn’t have much to lose. I’m glad I did. This product worked almost immediately! After the first trip (I drove about 40 miles) there was no leak. I think “Admin” is right on when he says it will have a better result. I will post final result at the end of my 500 miles.

  346. 1999 Saab 9-5 says:

    1 week ago I changed the oil on my 2.3L Turbo 1999 9-5 Saab. It had a small oil leak (out of the timing cover I believe) which I knew about when I bought it 9 months ago, but I never had to add any oil in between changes. The last change I used a synthetic blend, and this time I used Full Synthetic, both times 10W-30. Two days after this last oil change I sprayed two cans of Engine Degreaser on the undercarriage to clean away the long-term buildup from the small oil leak. It also had a small coolant leak which I have had to top off twice since owning the car. So, of the following past history, I am unsure of what has caused the issue. This week I noticed the car wanting to die immediately after starting and would have to give it some gas to keep it running. I also noticed at the same time that the car was smoking from the tailpipe. It is not black or blue smoke, it is white. It smells like a combination of a diesel tractor and burning charcoal. By the smell and color, I would say it’s coolant mixing and burning. However, the coolant level is fine, but just after a week the oil level went from mid range to just below the low level. What does synthetic oil smell like when burned? There is also oil residue at the end of the tailpipe. The white smoke has also went from barely noticeable to bad enough to where nobody can see clearly when driving behind me. There is no sign of oil foaming when checking the level, but smoke does escape when taking the cover off. Last time driving, I rolled the windows up and the car acted as if it wanted to die and the oil light would illuminate. I also noticed a slight rattling sound that correlated with the RPM’s. What does all of this sound like? Is it a head gasket? Cracked cylinder head? Intake manifold? Air/turbo intake? Besides the small oil leak, the car ran perfectly before the oil change.

    • admin says:

      It does NOT sound good! I would probably first start with a cooling system pressure test to rule out a possible internal coolant leak…like from a head gasket. If the pressure test is ok, I would follow up on the rattle noise you hear to see if its from an internal engine part like worn out bearings or from the valves etc. etc. It could be a turbo charger failure causing both the smoke and the poor idle.

      Hate to burst your bubble here, but these cars are not very well made, that is why you don’t see many on the road anymore. 11 years old and a turbo….not good. They put turbo chargers are small engines to give them power, but it over works the small engine and the lifespan is greatly depreciated because of this “steroid” turbo charger.

      I don’t really know if changing the oil had anything to do with it, my grandfather always told me if you have been using a certain brand and weight of engine oil for more than 25,000 miles stick to it and never change. He was a pretty wise old man and I have personally followed his instruction….without incident knock on wood.

      I would be very cautious here NOT to over spend on the repairs. Any internal engine work at this point, would be a bad investment decision in my opinion. You need to find a Saab mechanic, one who really knows these vehicles…and most mechanics DO NOT. You also need a mechanic who is familiar with turbos, and most are not. Going to the wrong mechanic will cost you big time!

  347. Greg Pytanowski says:

    The instructions on use of K&W Engine Block Sealer state that after installation of the sealer idle for 20 minutes and do not drive or rev the engine however in your recommendation you said to drive the vehicle 500 miles. Which way should I go on this one, i.e. do not drive or drive 500 miles with the sealer?

    • admin says:

      it has been my personal experience with this product over the last few years that driving the vehicle for about 500 miles or so has a much better result than the manufacture’s instructions state. We have used this product well over a 100 times in my shop over the years and I would say 90% of the time it worked to repair a leaking head gasket when it was used in the manner which I suggest. Since the engine does not have any freeze or boil over protection without the antifreeze there is a small risk of doing more damage if the engine overheats or the water inside the engine freezes but I would say the risk is small and if the headgasket is already damaged…you dont have much to lose.

  348. Alex says:

    Thank you for advice.
    Do you recommend to drain antifreeze out and add the water when you use BARS Radiator Stop Leak ??

    • admin says:

      If you are using BARS Leak Stop, you can use Antifreeze use but no antifreeze if using the headgasket sealer additive

  349. Bob says:

    Question. What size of K&W do you use for this method. Amazon lists a 16fl.oz can and a 32fl.oz plastic bottle. I ordered the 32oz plastic bottle. I just don’t want to use too much and plug things up. I am using it on a 95 Jetta.

    Also, Great site! Since my thermostat is such a PITA spot to get to I am liking your method a lot better. Hope it works ๐Ÿ™‚

  350. J Subaru says:

    I tried this fix last summer and seemed to hold well until now, when the temp shot up and the check engine light came on, which it didn’t do before. You mentioned the coolant has to be completely drained but it seems there will always be some left – is simple draining enough? Thanks for sharing this tip by the way, I think I will try it again

    • admin says:

      The product will not work if it comes in contact with antifreeze, so try to get as much of the antifreeze out of the system as you can drain out. Yes, there will be SOME left in the system, that seems to be ok in my experience.

    • admin says:

      BTW, ALWAYS get a cooling system pressure test first before you jump to conclusions and start guessing at things. This could be a simple hole in a radiator hose causing coolant loss and engine overheating.

  351. Alex says:

    Hi,I have Pontiac Grand Prix Se 1999 and I have a lower intake manifold leak problem( because of the damaged gasket). What would be your suggestions?

    • admin says:

      You will more than likely have to replace the lower intake gasket. You can try the headgasket sealer, but it takes contact with combustion gases to make the copper flakes melt and seal the leak. I dont think you are going to be able to achieve that. I have used BARS Radiator Stop Leak before on a intake gasket and it worked. Its a cheap and easy supplement you can buy at any auto parts store. If money is tight, it would be worth a try. I have not seen any adverse effects of using the BARS product.