Gasoline

Black or Gray Smoke

Smoke may be coming from incomplete fuel combustion

Clogged air filter

Carburetor, choke, fuel injection or emission system malfunction

Ignition timing off

Blocked manifold

Oil leaking in exhaust system

Blue Smoke

Engine oil being burned

Oil leaking into combustion Worn piston rings, valves or cylinders

White Smoke

Coolant and / or water being vaporized in combustion chamber

Engine too cold (no repair needed)

Head gasket leaking

Cracked block or cylinder head

Diesel

Black or Gray Smoke

Smoke may be coming from incomplete fuel combustion

Faulty injection system

Clogged air filter

Wrong grade of fuel

Timing may need to be adjusted

Engine overheating

Oil Leaking on exhaust system

Blue Smoke

Engine oil being burned or atomized

Engine oil level too high Worn piston rings, valves or cylinders

White Smoke

Fuel is not burning

Engine too cold (no repair needed)

Faulty injection system

Incorrect timing

Engine overheating