Expert: Skip Bollinger - 10/24/2006

Question
I have a 94 3000gt that has an after market exhaust. I have a problem with the exhaust smoking when i take off, its like a whiteish, blue smoke and it only does it if the engines cold or i take off. People have told me it could be my piston rings, but it doesnt do it all the time. If you have any sugestions please let me know
                                Thanks

Answer
Collins,
  I'm a parts specialist NOT a tech but I will offer my thoughts.
  Blue smoke is oil, White is either steam OR automatic transmission fluid. What could be happening is, when you let it sit overnight, oil runs down the valves past the valve stem seals. It gets into the combustion chamber and is burned off while the engine is cold. Once it burns off, it is done until the next cool down. You are not clear as to how you are driving when "i take off" but if you are hammering the engine, there is a possibility that the vacuum created in the combustion chamber is sucking oil down past the valve stem seals and burning it.
  Yes, it could be the piston rings but I think it would do it more than just when it is cold. You might run a compression check on the engine. There are 2 tests, dry and wet. Do a compression check "dry". Write down all the compression figures for each cylinder. Next, squirt oil into the spark plug hole and check that cylinder again. Continue with all cylinders. IF the compression comes up, it is probably the rings. If not, it is not the rings and I would look at the valve stem seals & or valve guides.
  I hope this helps. Good luck.
 Skip
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