An overheating engine typically results from a failing cooling system or a problem keeping the heat in the engine within its correct limits.

To prevent your car engine from overheating, first, you’ll have to pinpoint the problem. It’s more than likely something to do with the cooling system, but it could be any one of a handful of issues.

Why is my car engine overheating?

Problems with an overheating engine are some of the most serious a driver can face. If ignored, they can result in engine damage costing thousands of pounds to replace or repair, or worse still, depending on the age and value of the car, not worth repairing at all.

When the engine temperature is dangerously high, don’t take any risks driving it to your mechanic; have it towed or collected. The drive may only be a mile or two, but that’s often enough to seize an engine under the wrong circumstances; it could be the most expensive drive you ever take in your car.

What are the common causes of an overheating car engine?

Not enough or no coolant

Risk level – High

What to do Fill the coolant reservoir with the correct coolant for your car.

The first thing to check when your temperature gauge is heading into the red is your coolant level. If there isn’t enough coolant to keep your engine at a safe temperature, it can’t do its job. Make sure that the level of coolant is well within the recommended limits.

The cooling system is leaking

Risk level – High

What to do – Repair the leak or replace the leaking component.

You should be able to spot obvious signs of a leaky cooling system by puddles of coloured liquid underneath the engine bay of your car. You might be able to trace the leak by following the path of dripping coolant to damaged hoses or other faulty components.

To differentiate a cooling system leak over other types, coolant is coloured and has a sweet smell; the most common tints are green, blue and orange, depending on the type required by your car.

The water pump has failed

Risk level – High

What to do – DO NOT DRIVE. Replace the water pump immediately.

A broken water pump delivers several associated problems—all severe. In many cases, a failed water pump can kill your car; don’t risk driving it; get it replaced safely and as soon as possible.

There’s a problem with the radiator or radiator fan

Risk level – High

What to do – Repair or replace the radiator.

The radiator is full of tiny fins and channels designed to remove the heat from the coolant. If the radiator is leaking, blocked, or the fan isn’t blowing cool air over it, then it’s likely to lead to problems with the heat in your engine.

The thermostat has failed

Risk level – High

What to do – Replace it immediately.

Your thermostat’s job is to regulate engine temperature. If it isn’t working properly or has broken completely, then your engine temperature could be swinging all over the place, ultimately too high, and leading to irreparable damage.