A vehicle's exhaust color can reveal problems in the combustion chamber. If the vehicle emits white smoke and continues to do so after startup, further inspection is required. This is because coolant is entering the combustion chamber and burning white when ignited.
This is often the result of an overheated engine. Overheating an engine can quickly cause a warped cylinder head and a blown head gasket. A damaged engine block will also cause this condition.
The intake manifold gasket on some engines can leak, resulting in coolant entering the chamber and burning white. If excessive oil enters the combustion chamber, blue gray colored exhaust will result. Excessive fuel in the combustion chamber results in a rich fuel mixture and black colored exhaust.