One question we get often has to do with smoke emitted from the car’s exhaust system.

What do exhaust smoke colors mean? Our technicians explain what the color of your exhaust smoke could imply depending on if you have a gasoline or diesel engine.

Cars with a gasoline engine

If the vehicle has a gasoline engine, here are the most common reasons the exhaust would release colored smoke:

Black or gray exhaust smoke

Black or gray exhaust indicates the engine isn’t burning fuel correctly. There are several different explanations:

• Oil leak
• Fuel injector malfunction
• Clogged air filter

Blue exhaust smoke

Blue exhaust smoke is most likely caused by the engine burning oil. This might mean:

• Oil leaking into the combustion chamber
• Worn valves or cylinders
• Old piston rings

White exhaust smoke

Before worrying about white exhaust, check that it’s actually smoke and not steam. Steam is rarely suggests there’s a problem. However, thick white smoke potentially means:

• The engine is too cold
• Leaking head gasket
• Damaged block or cylinder head

If your vehicle has colored smoke coming from the tail pipe, don’t wait to schedule an exhaust system inspection with our car and truck repair shop in Frisco, TX.

Vehicles with a diesel engine

While diesel and gasoline engines are similar, the combustion process is slightly different. Diesel engines don’t have spark plugs because they run at a much higher temperature. Colored exhaust coming from a vehicle that uses diesel could mean a variety of things.

Black or gray exhaust smoke

Gray or black exhaust smoke in a diesel engine could be indicate many different issues:

• Wrong grade of fuel used
• Clogged air filter
• Overheating engine
• Leaking oil
• Problematic injection system
• Improper timing

Blue exhaust smoke

Blue exhaust smoke in a diesel vehicle means one of two things. The oil is being burned or atomized. Some causes of this problem are:

• High engine oil levels
• Worn out piston rings
• Old valves or cylinders

White exhaust smoke

White exhaust coming from a diesel-fueled car is reason for concern. It means the fuel is not being burned correctly. This could suggest:

• The engine is too cold
• Incorrect timing
• The engine is overheating
• Faulty injection system

Schedule exhaust system service with our Frisco auto shop

If you ever see exhaust smoke coming from your vehicle, it’s time to wake up. Make sure your vehicle is running as normally and your exhaust system is in good condition. Call Christian Brothers Automotive Frisco West for an exhaust system check today!