Car Overheating? What To Do and What Causes It

What to do straight away

If the temperature gauge climbs into the red or a coolant warning light comes on, pull over as soon as it is safe and switch the engine off. Carrying on can warp the cylinder head and turn a cheap repair into an expensive one.

Do not open the coolant cap while the engine is hot. The system is under pressure and the coolant can scald. Let it cool for at least 30 minutes before checking the level.

Common causes

Low coolant from a leaking hose, radiator or water pump is the most common cause. A thermostat stuck shut, a cooling fan that does not switch on, or a radiator blocked with debris can all stop the engine shedding heat.

On cars where the water pump is driven by the cambelt, a failing pump is worth checking when the belt is due.

Signs of a head gasket problem

White smoke with a sweet smell from the exhaust, coolant disappearing with no visible leak, bubbles in the coolant expansion tank, or a creamy residue under the oil cap can all point to a head gasket failure. We can test for this before any strip-down.

Overheating diagnosis in Brierley Hill

We pressure test the cooling system, check the fan, thermostat and pump, and test for combustion gas in the coolant, so we can tell you exactly what has failed. Call 01384 936310.