Diagnostics · Expert tip
White vapor on cold start is usually harmless
Water vapor clears when warm; real white smoke does not.
The expert tip
- A little vapor on a cold start is condensation
- If it persists and coolant drops, suspect the head gasket
- Blue smoke = oil; black smoke = too rich
Source: Diagnostic experts
Apply tips that match your car and manual. For anything safety-critical or high-voltage, use a qualified mechanic.