Can I just top up with water in an emergency?

In a genuine roadside emergency, plain water will get you to a garage. But have the proper antifreeze mix restored as soon as possible — water alone boils sooner and corrodes the system.

Why does my car overheat only in traffic?

At speed, airflow cools the radiator naturally. In stationary traffic that airflow disappears and the cooling fan must do all the work — so a weak or failed fan shows up exactly there.

How to Prevent Engine Overheating (UK)

An engine produces an enormous amount of heat, and the cooling system's only job is to carry it away. In a summer tailback, or hauling a caravan up a long incline, that system is working at its limit — which is exactly when any weakness shows up as a climbing temperature gauge.

Before the warm months

Check the coolant level and that it's the correct antifreeze mix — not plain water topped up over the years
Inspect the radiator for leaks, and the fins for dirt, leaves and bent vanes
Confirm the cooling fan kicks in when the engine gets hot
Look for soft, bulging or perished coolant hoses

If the gauge climbs into the red

Switch off the air conditioning and turn the cabin heater to full — it sounds backwards, but it pulls heat away from the engine. If the gauge keeps rising, pull over safely and switch off. Let everything cool completely before you check anything.

Engine Overheating: Causes and How to Keep Your Engine Cool

Before the warm months

If the gauge climbs into the red

Frequently asked questions