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Q: Tailpipe smoke

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For quite some time I've had noticeable tailpipe smoke. Only after its been idling(at a stop sign or more so at a red light); only when I initially step on the gas then it dissipates ; I get a trail of smoke behind the car, well at least used to-now it's a cloud puff! Overall the car is still running rather well... it doesn't overheat; although a small (oil leak? Which it's had since I bought it several yrs ago) no excessive fluid loss of any kind; it doesn't have quite as much power/speed going up a hill as it used to; no delay in power driving around town, excellent on the high way; while driving if you didn't notice the cloud in the rearview mirror you wouldn't think anything was wrong with the car...?

My car has 196,000 miles.
My car has an automatic transmission.

If you are not loosing coolant then the smoke is from oil getting into the exhaust through the combustion chamber. This could be coming from a few places or all of them. The oil control rings on the pistons may be letting too much oil in. The valve seals can leak oil through to the intake valves. The head gasket can leak oil in to the combustion chamber. Any of these can be the problem. It is almost impossible to isolate any one of these. You should start by replacing the PCV valve and checking for excessive crankcase blow this would indicate you have bad rings. Check and make sure you are not overfilled with oil and check the spark plugs for oil fouling. If you need some help with this, consider YourMechanic, as one of our mobile experts can come to you and diagnose the smoke coming out of your exhaust. They will be able to help you pinpoint the leak as necessary.

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