Why does my car overheat and then cool down?

Classic symptom of a stuck thermostat opening late, a failing water pump, or the early stage of a head gasket failure.

Here's a quick, honest answer from a working UK mechanic — what causes it, what it costs to fix, and what to do next.

How urgent? — Drive home only. Each overheat cycle risks warping the head.

Can I just keep topping up the coolant? — No — find the leak. Stop-leak products often cause more damage than they fix.

Bob's Mechanical Repairs — independent family-run garage in Birnam, Dunkeld, Perthshire. Call 01350 727 276 or email bob@bobsmechanicalrepairs.co.uk.