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Q: Smoking exhaust on starts

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Every time my car sits for a while and then I start it, it emits a cloud of smoke from the exhaust. It goes away right after a few seconds. It's only when I first start it. Can you tell me what this could be?

A: The smoke coming from your exhaust may be f...

The smoke coming from your exhaust may be from three things. The normal start up moisture in the exhaust is considered normal if the smoke looks white and is not too heavy and goes away within a minute. The next cause is coolant entering the combustion chamber and this would emit a white smoke also, but will tend to get worse or will not go away in most cases. This is usually due to a gasket leaking. You may also notice the coolant level may be going down and you have to add coolant. The last cause would be oil getting into the combustion chamber. The smoke would have a blue to black tint to it and may leave an oily residue on the tail pipe. The oil could get into the chamber through the valve seals and guides or the piston rings. The engine may also use excessive amounts of oil. You may want to have a mechanic, like one from YourMechanic, come inspect your vehicle’s exhaust smoke to see if there are any major problems that should be fixed.

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