Common Causes of Vehicle Smoke

• Engine Type: Gasoline
• Visible Sign: Black or Gray Smoke
• Diagnosis: Smoke Incomplete fuel combustion
• Possible Causes:

1. Engine too cold (no repair needed)
2. Clogged air filter
3. Carburetor, choke, fuel injection or emission system malfunction
4. Ignition timing off
5. Blocked manifold

• Engine Type: Gasoline
• Visible Sign: Blue Smoke
• Diagnosis: Engine oil being burned
• Possible Causes:

1. Oil leaking into combustion chamber
2. Worn piston rings, valves or cylinders

• Engine Type: Gasoline
• Visible Sign: White Smoke
• Diagnosis: Coolant and/or water being vaporized in combustion chamber
• Possible Causes:

1. Engine too cold (no repair needed)
2. Head gasket leaking
3. Cracked block or cylinder head

• Engine Type: Diesel
• Visible Sign: Black or Gray Smoke
• Diagnosis: Incomplete fuel combustion
• Possible Causes:

1. Faulty injection system
2. Clogged air filter
3. Wrong grade of fuel
4. Incorrect timing
5. Engine overheating

• Engine Type: Diesel
• Visible Sign: Blue Smoke
• Diagnosis: Engine oil being burned or atomized
• Possible Causes:

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

• Engine Type: Diesel
• Visible Sign: White Smoke
• Diagnosis: Fuel is not burning
• Possible Causes:

1. Engine too cold (no repair needed)
2. Faulty injection system
3. Incorrect timing
4. Engine overheating