White Exhaust Smoke
Urgency: CriticalA small amount of white vapor on cold starts is normal condensation. However, persistent thick white smoke indicates coolant is leaking into the combustion chambers, usually from a blown head gasket, cracked cylinder head, or cracked engine block. This is a serious condition that can lead to engine overheating and failure.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonPossible Causes
- Blown head gasket
- Cracked cylinder head
- Cracked engine block
- Failed intake manifold gasket
- Condensation (cold weather — normal)
Related OBD-II Codes
When to See a Mechanic
If smoke is thick and persistent (not just cold-weather condensation), see a mechanic immediately. Check coolant level — if it's dropping with no visible leak, a head gasket issue is likely.
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