Engine Overheating
A temperature gauge in the red, a warning light or steam means the engine is overheating. Common causes are low coolant, a failed fan, thermostat or water pump.
Critical risk
Stop safely and switch off the engine. Driving an overheating engine can destroy it.
Short answer · What should I do if my engine overheats?
Turn off the air conditioning and turn the heater to full to move heat away. As soon as it is safe, stop and switch off. Do not open the coolant cap while hot. Once cool, check the coolant level. Have the cause repaired before driving on.
Safe checks you can do
- Stop and switch offHazard lights on, engine off.Never open the coolant cap on a hot engine.
- Let it coolAt least 30 minutes.
- Check coolant and fanLevel when cold; fan running when warm.
Questions that narrow it down
- Is coolant low?Leak somewhere.
- Does it overheat mostly in traffic?Cooling fan problem.
- Does it overheat on the motorway?Radiator, pump or thermostat.
Possible causes
Listed without ranking. Use the questions above to see which ones fit your car.
- Low coolantLeak.
- Failed cooling fanOverheats in traffic.
- Thermostat stuck closedNo flow to radiator.
- Failed water pumpNo circulation.
- Head gasket failureCombustion gas in coolant.
Questions about Engine Overheating
Why turn the heater on?
The heater core works as an extra radiator.
Can overheating damage the engine permanently?
Yes, it can warp the cylinder head and damage the head gasket.