Car overheating
If the temperature gauge climbs into the red or a coolant warning lights up, pull over and switch off. Driving an overheating engine can warp the cylinder head within minutes.
Can I keep driving? Stop driving as soon as it is safe. Continuing can cause severe engine or transmission damage.
Common causes
Low coolant
A leak from a hose, the radiator, water pump or heater core.
Thermostat stuck closed
Coolant cannot reach the radiator.
Cooling fan not working
Overheating mainly in traffic or at idle.
Failed water pump
Often with a leak or noise from the pump.
Blocked radiator
Internally with deposits or externally with leaves and insects.
Head gasket failure
Combustion gas in the coolant, bubbles in the expansion tank, white exhaust smoke.
What to check
- Stop and let the engine cool. Never open a hot cap.
- Check the coolant level when cold.
- Look for leaks and wet spots.
- Check that the fans run when hot or with A/C on.
- Have the system pressure-tested.
Related OBD2 codes
Repair guides
General guidance only. A qualified technician can confirm the cause; brakes, steering and fuel leaks should be checked professionally if in doubt.