Car symptom
White smoke from the exhaust
White smoke can be harmless condensation — or serious coolant burning.
Most likely causes
- Normal cold-start condensation
- Head gasket (coolant burning)
- Cracked cylinder head
- Weak glow plugs (diesel)
Checks to run
- Does it clear once warm?
- Check the coolant level
- Look for milky oil
- Compression / leak-down test
Tools you may need
Compression tester
Leak-down tester
Confirm before replacing. These are hypotheses to check — never buy parts on a guess. If the fault involves brakes, airbags or fuel under pressure, use a professional.
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FAQ
It depends on the cause. Some causes are cheap and quick; others (like a head gasket or seized caliper) need attention soon. Work through the checks in order and confirm before replacing parts.
Start with the free checks listed here. If they involve high voltage, fuel under pressure, airbags or brakes, let a professional handle it.
The interactive diagnostic asks targeted questions to narrow it down, and every cause must be confirmed with a measurement — never guess.