Skip the auto shop - Our mechanics make house calls

Q: Skipping, light rough idle, & smoking

asked by on

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: vibration and smoke from tail pipe

Check for diagnostic trouble codes. If the smoke is blue, oil is getting into the combustion chambers and perhaps the rough running is due to partly fouled plugs. If the smoke is black, the air fuel ratio is way off...

Q: Gears of a morning

Firstly, it's important to know the model and engine of your vehicle for an issue like this. From what you've described, this sounds like you have a fluid pressure leak internal to the transmission. The pressure in the transmission is...

Q: Cylinder 2 Misfire, and water contamination in the fuel.

Hello. If your fuel was recently contaminated with water then that is likely the reason behind the cylinder 2 misfire. As the fuel travels to all of the cylinders, this leaves them all susceptible to misfires, as well as the...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...