Q: Skipping, light rough idle, & smoking

asked by on October 31, 2016

Car is skipping changed spark plugs and coils but problem is still there. It also smokes from the tailpipes, under the hood from back passenger side and underneath the car. What could it be?

My car has 114000 miles.
My car has a manual transmission.

Hi and thanks for contacting YourMechanic. Depending on what color the smoke is will determine what is happening with the engine. If there is heavy black smoke, then there is too much fuel in the cylinders and the fuel is burning off in the exhaust system.

If there is blue smoke, then the engine is burning excessive oil caused by the oil rings or valve guide seals being worn. If the smoke is white, then the engine is burning coolant, which could be entered into the combustion chamber by a burned head gasket, a crack in the cylinder head, or a crack in the intake coolant jackets into the intake runners.

The smoke will let you know what is happening with the engine an where to begin testing the engine.

If you need further assistance diagnosing the smoking and rough idling issues, then seek out a professional, such as one from YourMechanic, to help address these problems.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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