What Does the Color of Your Car Exhaust Mean?

car exhaust colorThe fumes coming out the tailpipe reveal quite a bit about the condition of your car. Of course, a bit of emission is normal; however, the color of the car exhaust may indicate that you need to bring your vehicle to an auto repair service. We recommend that you examine the fumes periodically for any discoloration.

Car Exhaust Color Indicator


Blue smoke means the engine is burning oil. A worn piston ring or valve guide seal is likely the cause of the oil leak. Some of that oil is making its way to the combustion chamber where it’s burning along with the fuel. Burning oil can damage the spark plug and lead to rough starts.

If your car has a turbocharged engine, blue smoke could also be an indicator that the blower is damaged.


Gray smoke can mean several things. It can be an indicator of any of the same problems associated with blue smoke. However, it can also mean that transmission fluid is burning in the engine. The cause for this may be a worn transmission vacuum modulator.


Black fumes mean the engine is burning more fuel than normal. Several culprits may be responsible for this, such as a dirty air filter, a worn fuel pressure regulator, or bad fuel injector. Black smoke is easy to diagnose and fix by an auto service. Delaying repairs will have an adverse effect on fuel economy.


Car exhaust is normally white. However, this may not necessarily mean everything is A-Okay. If the fumes appear more like smoke than vapor, then it may mean the engine is burning coolant. This may be the result of a cracked engine block, damaged cylinder head, or a blown head gasket.

We’ll Diagnose the Problem

Seeing irregular-colored fumes? Bring your vehicle over to Monroe Foreign Auto Repair. This applies for hybrid car owners as well. We will determine what is causing the abnormal color of your car exhaust.

Edited by Justin Vorhees

Car Diagnostics for Regular, Hybrid, and Foreign Cars

Serving customers in Clearview, Duvall, Gold Bar, Index, Lake Stevens, Maltby, Mill Creek, Monroe, Snohomish, Startup, Sultan, Woodinville.