Austin,

I was wondering if maybe you could help me out.  I recently  purchased a 1986 Nissan 300ZX non-turbo for use as a beater/daily driver.  The car has been overheating since I bought it.  So far I  have flushed the system 4 times, replaced the thermostat, radiator,  radiator cap, and a ruptured lower radiator hose.  The car is still  overheating, even after having done all of that!  I’m at wits end with this monster!  What could possibly be causing it??  The previous owner believed the car has a blown head gasket.

However, there is no transfer of fluid between oil and coolant, and no smoke coming out of the tailpipe, and other than getting hot, it runs like a champ.  I don’t know where to look next and it’s driving me nuts!

Joe

Hey there Joe,

Get a cooling system pressure test first   Then check the electric cooling fan operation or fan clutch if you have one.

Also make sure you have bled the cooling system and there are no air  bubbles in the system. Turn on the heater so the heater core fills  with coolant just to make sure there are no air pockets in the system.

Blessings
Austin Davis

Reader Reply

Austin,

Thank you for your prompt reply.  No wonder so many people ask for your help!  I actually fixed the problem last night.  It was definitely air in the system.  I had to reposition the thermostat with the jiggler valve up (should have read that in the shop manual!) and manually burp the system by squeezing the lower hose to get the air out of the block.  Drove it around for over 20 miles of mixed driving, and even having to stop for the world’s longest freight train and it now sits dead center on the gauge.

Thanks Again!
Joe

Hey bro well I have a 1991 Honda Civic DX which was running fine till a few days ago it has been overheating and like the engine is shaking really hard also the is smoke coming from the tail pipe now any idea what it could be. it would be really helpful…….also I replaced the radiator and cap all hoses and thermostat, but not the water pump
Thanks
Jose

Wuz up Jose

This does not sound good. I would have a mechanic perform a “compression test” on the engine to see if there is internal engine damage……like a blown head gasket. I would GUESS that the engine overheated, due to a coolant leak, restriction in the radiator, or a faulty electric cooling fan etc. etc. and the head gasket or other internal engine part failed causing coolant to enter the inside of the combustion area where it is not supposed to be.

If your mechanic thinks the head gasket is the problem, you might try this cheap radiator additive

Head Gasket Sealer

Although, you still have to fix the original cause of the overheating problem…..like get a new radiator or correct the coolant leak etc. or what ever caused the engine to over heat in the first place.

Blessings,
Austin Davis

Hi Austin,

I have a 2000 Subaru, in July 2008 I had the head gaskets redone, now less then one year later my car overheated and the mechanic put in a new radiator but it is still over heating, so he now says I need to pay another $2,000 and get the head gaskets done again, Can this be right? he says that because the radiator was 9 yrs old it just went bad and that is why it over heated,
Thanks Marti

Hey there Marti

I would DEFINITELY get a second opinion preferably from the dealership or Subaru specialist on this before you do anything. A simple cooling system pressure test can prove if you have a head gasket or other internal engine damage. If the engine overheated long enough, yes, you could have head gasket issues and a restricted radiator can be the cause of the overheating.

These articles might help you

Head Gasket Symptoms

Head Gasket Sealer Additive

Head gasket repair

Blessings,
Austin Davis

Hi Austin,

We had a 1997 Suburban that was recently totaled and we are looking to replace it. We have found one Suburban that is priced very well, but seems to have a major issue. It’s getting coolant in the oil following an oil change. It seems like it might be a blown head gasket or maybe even a cracked block.

I’ll post the seller’s description below. We would like to know the likely culprit as well as the worst case scenario and the probably costs of the repairs. It’s priced well enough that even if we had to put $2000 in it it would be a good buy. Much more than that and it’s probably better to pass. The motor has 116k miles and it’s a 1999.

The seller said:

I changed the oil and filter and after that the oil pressure pegged the needle. The gauge reads up to 80 psi. I was told to put a new filter in as there had been some bad filters that would not bypass and could cause this problem. I did and the pressure returned to normal. After that I started getting coolant into the oil.

Some more questions and a little internet searching and the conclusion is that the high oil pressure pushed out one of the pressed in plugs in the oil galley and therefore is letting coolant get into the oil. I have completely flushed the coolant and oil, with new oil and a filter. It is now sitting with no coolant in it at all.

Thanks for your insight.

Blessings,

Ann

Well hello there Ann,

Thanks for your email. Honestly……I would steer clear of this vehicle, there are just WAY too many good used vehicles on the market with less problems. This engine COULD need a head gasket replacement or some other internal engine repair and your $2,000 could be used up pretty quickly. This is a 10 year old vehicle and there will be other maintenance and repair issues as well as this major one you know about.

If you are DEAD SET on this vehicle….and kinda seems like you are, take it to your local auto mechanic and tell them your concern and that you want a “cooling system pressure test” to see if there is an internal coolant leak. I personally would leave the pressure tester hooked up to this vehicle for an hour or more to make sure there is not an internal coolant leak.

If it passes the test…..then I would take a chance and buy it. if it failed the test and there is a confirmed coolant leak, I would pass.

I have had some great results with this inexpensive over the counter head gasket additive.

Head Gasket Repair

I got my fingers crossed for you!

–
Blessings,
Austin Davis

http://www.trustmymechanic.com

http://www.myhonestmechanic.com

Hi there,

I have a 1994 Toyota Camry that started overheating about a week after I bought it. It only does this at idle speeds. I had a pressure system check done, a new thermostat put in, and a new cooling fan installed. It stopped overheating for a couple of weeks, but then started doing it again.

One mechanic I took it to thought it was a blown head gasket, the other said he wasn’t sure if it was the head gasket, but put in the fan and thermostat. I have to add new coolant/water to it about every 3 days, and it takes about half a container each time. If I neglect to fill the radiator up it will overheat.

I never see anywhere that is leaking, and when it says its overheating I always pull over and inspect the engine and it does seem pretty hot. I have new radiator caps on and every time I take it for a pressure test they say there is no leak. Its driving me insane! I cant figure out what to do about this car! Any suggestions??
Thank you so much!
Laura

Howdy Laura,

You HAVE a coolant leak somewhere. I would highly suggest you go to the dealership or another mechanic and have them pressure test the cooling system….if you are adding coolant on a regular basis, there has to be a leak in the cooling system. The pressure test should also determine if you have a head gasket leak….but you did not mention anything about white smoke out the tailpipe, running rough or a check engine light coming on….I would expect to see those symptoms with a head gasket leak.

I would triple check the cooling fan is working correctly as well. Usually overheating at idle or slow speed complaints are related to an electric cooling fan that is not working. Get out of the car with the engine running when the engine is overheating, you should hear the cooling fan running up near the radiator if it is working correctly.

If for some reason a head gasket is indeed suspected, you might want to try this cheap over the counter head gasket sealer you can buy at any local auto parts store. I talk about this in more detail on these pages

Blown Head Gasket Symptoms

Head Gasket Block Sealer

Hopefully it is something relatively simple and easy to repair. Keep me posted please.

–
Blessings,
Austin Davis

About two months ago the check engine light on my 1996 3.8L V6 Chevy Camaro came on. I went to an auto parts store where they read the code and told me I needed a new EGR valve because mine was only function at 10% of what it should be. Well, my mechanic disagreed, saying the EGR valve should not go bad after only 90,000 miles.

So, I continued to drive it until it began misfiring violently at very random times. I took it back to my mechanic. He read the code which said their was a problem with the EGR valve pintel position. He took the valve off-it didn’t change the misfire. He said the valve appeared to be clean and not clogged with carbon.

He still didn’t believe the problem was with the EGR valve. He said the EGR valve should only make it misfire during idle, not at driving speeds. So, I drove it until it began to smoke. My father examined it and said my catalytic converter was clogged. So, $500 later the cat was replaced. The misfire continued until the computer was reset. Then, the car ran beautifully…for about two days.

Then, the check engine light came on with the same EGR pintel position code. My mechanic checked my coolant on a hunch and said he believe their was oil in the radiator because the fluid looked foamy. He said it could be caused by a blown head gasket. However, my radiator fluid (the orange gunk that only GM uses) has ALWAYS looked foamy and separated, and I’ve never had this problem or a loss of oil.

So, my question is do you think the code is still stuck in the computer? Or do you think the EGR valve is bad? Or perhaps a blown head gasket? Again, my mechanic said a head gasket would only cause a misfire while the car was warming up. And at this point, most of the misfiring comes after the car has warmed up.
Thanks!
Amy

Hello there Amy

You need to find a REAL mechanic, I don’t think this current one is capable of diagnosing a computer related problem like this….and he will probably spend 5 X’s more money guessing at parts rather than spending $85 for a proper diagnosis at the dealership.

You can always get this mechanic to do the repairs once you are sure what the problem is. Sounds like a problem with the EGR valve or a sensor connected with the EGR system…..but it could be something as simple as a bad spark plug wire causing the missfire and check engine light BUT an EGR code is stored in your memory.

If you just want to guess……then replace the EGR valve and cross your fingers.

Blessings,
Austin Davis

I got it changed there a few months ago and shortly thereafter my car started to overheat and the heater stopped working. If I revved the engine really high it would cool off and if I was idling the engine would get really hot but the heater still blew cold air (this was in February in Utah.

I decided to check my coolant thinking that maybe I needed to get it changed out. When I opened my coolant reservoir it looked like a melted chocolate milkshake… I even stuck my finger in to see what the consistency was… it was thicker than coolant but not by much.

I checked the oil and it was fine on the level and was still that greesy black color. I took my car to my normal mechanic and he said that first thing is that we should do a coolant flush, but that it sounds like my car has a blown head gasket.

I dropped the car off and talked to him the next day and he said that he can’t even get the car to drain, the coolant was too thick. I called the Jiffy Lube and asked the manager there if there was any way it could have been them, he said that the coolant must have gotten bad some other way.

I had the thought that they may have added oil to the coolant instead of the oil resivoir… He ensured me that there was no way they would have done that, but he flushed most of the old coolant out for me and filled it back up with clean, and yes, he did not flush all of the bad coolant, but a great deal… it was chunky.

He also topped off my oil that was now really low. My heater started to work again, but the engine still overheated. My shop guy told me that in order to get my gasket replaced I have to pay $900. I haven’t driven my car since and when I started it I could tell there was coolant somewhere in the engine because of the white smoke and the antifreeze smell.

My question comes to these:

1. Why was the antifreeze chunky and the oil didn’t have any issues at all?

2. I know you’re going to suggest a compression test, is there any way to do that without going to a shop… I am really short on cash and can’t even really afford the $65 or so

3. Is there any other way to tell if you have a blown head gasket? How good is the K&W product and is there any chance it will make my engine worse?

4. Lastly, how hard is it to change out a head gasket? I am pretty good with cars, I just hate working on my only vehicle…

~Brooke

Hey there Brooke

So your engine is overheating……all the time, or just at idle speeds? You DO have white smoke coming out of the exhaust pipe??? Does the engine miss-fire and run bad and does the check engine light come on? Are you continually adding coolant to the radiator?? I would expect all these things to be happening if you had a blown head gasket or an internal coolant leak.

Has your mechanic performed a cooling system pressure test to see if there is a leak in the system? If not get another mechanic, that is the first thing you do in a situation like this!!

I am not real sure what the junk is inside your radiator….it could just be rust, which I have seen “chunks” of rust in a cooling system before and the rusty water will look almost orange/chocolate appearance.

If you were in my shop I would FIRST pressure test the cooling system for leaks….this should also tell you if you have a leak internally to the engine like a blown head gasket. A compression test will tell you if the engine is worn out or there is an internal mechanical problem….which I don’t think you have.

If the pressure test shows that there IS an internal coolant leak then yes, by all means try the K&W Block Seal Additive I talk about on my site….I assume you read my article on how to use it (not like the directions on the can tell you how to use it) but here is the link again

Head Gasket Sealer Additive

If your mechanic even suspects there is an internal coolant leak…I would use the K&W additive anyway….it wont hurt anything if you don’t have a leak.

I have a STRONG feeling you will need to replace your radiator though BEFORE you try the block additive. If you have chunks of stuff in your radiator you most definitely have some restriction in your radiator and “flushing” will NOT remove the junk at the bottom of the radiator that is restricting your coolant flow to the engine.

You can get a fairly cheap after market radiator for this vehicle and install it yourself then do the block sealer trick.

The heater core is basically a small radiator inside the dashboard, so I would suspect your heater core is restricted with what ever this chunky stuff is hampering your heater operation. You might be able to remove both heater hoses under the hood and flush out your heater core with a water hose to remove any loose debris that is lodged in there.

Also you need to replace the thermostat….anytime you replace the radiator or do anything to the cooling system.

Keep me posted will ya?

Blessings,
Austin Davis