Other than flashing red and blue lights, there might be nothing worse to see behind your vehicle than smoke. Billowing fumes almost always mean there’s something seriously wrong with your car. But the color of that smoke might help you understand what type of repair can help fix it.
How your exhaust system works
Many engine problems create abnormal or excessive exhaust smoke. In your engine, fuel is burned in each cylinder, creating exhaust gases. These gases exit through valves in the engine and then flow through the exhaust manifold and into the exhaust pipes. Along the way, the gases travel through the catalytic converter, where any remaining fuel is converted to water to reduce emissions. Finally, the gases exit through the tailpipe.
When everything’s working properly, this exhaust is colorless. But if something is amiss, you’ll see a cloud of smoke coming out of the back of your car.
Color can point to the cause of exhaust smoke
There are three common colors of exhaust smoke emitted from a gasoline-powered engine:
- Blue-gray or gray-white