Blue Exhaust Smoke

blue smoke from tailpipeThere is blue smoke coming from my car exhaust only when it idle when I stand at a stop light and on a hot day there is a lot of blue smoke coming out of my exhaust when I do a reversed parking. I did replace my O rings but know this is happening.

Please tell me what can the reason be for this smoke, after all I did put on new o rings.



Hi Franklin,

I would probably be more suspect of a valve type of problem in the cylinder heads, worn valve stem seals possibly. You might make sure the PCV system is working properly and can try a can of Engine Restore motor oil additive (available at any auto parts store) to see if that helps.

A valve job is probably the solution…but I would need to do some testing to be sure, that is a big job to be guessing at. Ask your mechanic to do a cylinder compression test to see if one or more of the cylinders is weak on compression. This would at least tell you if there is excessive internal wear, most likely caused from a piston ring or damage to a cylinder wall.

The Engine Restore motor oil additive should be used after each oil change. It will help slow down oil consumption, which is what is happening if you have BLUE smoke out the exhaust tailpipe.

Blue smoke is the hardest to pinpoint the source out of the 3 different colors of smoke. Since the cause of the smoke is due to internal wear, and or leaking internal oil seals that you can not see from the outside. Sometimes you just have to remove the cylinder heads and visually inspect them and the internal cylinder walls for damage.

Since this repair is so labor intensive, its very expensive so you have to weigh your options, is the vehicle worth this kind of money or cut your losses and replace the engine…or the vehicle.

Blue smoke is due to an internal oil leak and oil is getting on the spark plugs.

Black smoke is from too much un-burned fuel (engine running “rich”)

White smoke is from coolant leaking internally in the engine and coolant is getting on the spark plugs.

Please share this with your friends
Austin Davis

Posted in: Exhaust Smoke

3 Comments on "Blue Exhaust Smoke"

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  1. Tyrone says:

    Could possibly be leaky valve seals try megapower @ if you cant afford a valve seal repair.

  2. ken says:

    Hi,I have 2001 Cadillac De Ville 4dr sedan.

    It burns a lot of oil and drips some,as well.Is there a simple solution to this?

    Thank you,Ken

    Blessings to you,too.

    • By Austin Davis says:

      Hey Ken,

      If the engine is BURNING/consuming oil there is not much you can do without tearing the engine apart. It could be a problem in the top half of the engine and removing the cylinder heads and doing a valve job might cure. Or it could be a problem with the lower end of the engine and a complete overhaul or replacement is going to be in order.

      What MIGHT help slow down the oil consumption would be:

      1. make sure the PCV system is working. There is a valve that plugs into the valve cover with a hose on it. Replace the valve and make sure there is suction on the hose to the valve with the engine running. This will remove excess air pressure from the engine.

      2 make sure the oil drain back holes inside the the top of the cylinder head are clean and allowing the oil to drain back into the engine. When the holes get plugged up with oil sludge the oil builds up inside the valve covers and creates pressure on the internal seals and gaskets. Removing the valve covers and cleaning out the drain back holes is the solution.

      3. Use thicker engine oil, like Castrol 20-50 UNLESS you live in a very cold snowy climate…would be too thick for that. You can also use a can of “Engine Restore” oil additive which does a pretty good job at reducing oil consumption.

      now, all EXTERNAL oil leaks will just have to be replaced. I have yet to find a sealer/additive that did any good at leaking external oil gaskets/seals.

      Hope this helps

      Blessings to you too!

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