What Does The Color Of Exhaust Smoke Indicate?
by FTE Published on Monday, February 2nd, 2026
Smoke color is key to understanding underlying engine issues and I’ve successfully diagnosed hundreds of smoke issues for drivers.
Exhaust smoke color can reveal what’s happening inside your engine.
Blue or blue-tinted smoke often signals oil burning, a possible sign of worn piston rings, leaky valve seals, or turbo seals.
White smoke can indicate coolant leaks into the combustion chamber, suggesting a head gasket issue. Black smoke is usually a sign of incomplete combustion, often related to a fuel system problem.
If you see persistent blue smoke, check your oil level regularly to monitor consumption.
With black smoke, try a fuel cleaner as a process of elimination.
With white smoke, check the engine coolant level and test the coolant for exhaust gases.


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