Cooling system guide

Car Overheating: What To Do

If your car is overheating, stop safely as soon as possible. Continued driving can cause severe engine damage. Common causes include low coolant, radiator leaks, thermostat faults, failed water pumps or cooling fan problems.

Quick answer

If the temperature gauge rises high, steam appears, or an overheating warning light comes on, pull over safely and switch the engine off. Let the engine cool fully before opening the bonnet or checking coolant.

Do not continue driving unless you are certain the issue is minor and temperature returns to normal immediately.

Common causes of car overheating

  • 1Low coolant level from leaks or lack of maintenance
  • 2Radiator leak or blocked radiator flow
  • 3Thermostat stuck closed preventing coolant circulation
  • 4Water pump failure reducing coolant movement
  • 5Cooling fan fault especially in traffic
  • 6Head gasket issues causing pressure or coolant loss
  • 7Incorrect coolant mix or contaminated coolant

Overheats in traffic

Often linked to cooling fan faults, blocked airflow or radiator issues.

Overheats on motorway

May point to coolant loss, water pump issues or circulation faults.

No cabin heat

Can suggest low coolant level or trapped air in the system.

Signs your car is overheating

  • Temperature gauge rising higher than normal
  • Steam from bonnet area
  • Coolant warning light or message
  • Sweet coolant smell
  • Loss of power or rough running
  • Heater stops blowing warm air

What to do if your car overheats

1. Pull over safely

Find a safe place away from traffic.

2. Switch engine off

Prevent further heat build-up.

3. Let it cool fully

Never remove the coolant cap while hot.

4. Check coolant level

Only once cool, inspect the expansion tank.

5. Look for leaks

Puddles, wet hoses or coolant residue may be visible.

6. Arrange repair

Recurring overheating needs diagnosis before normal use.

What not to do

  • !Do not keep driving with the gauge in the red.
  • !Do not open coolant caps while hot.
  • !Do not pour cold water onto a hot engine.
  • !Do not assume topping up coolant fixes the root cause.

Frequently asked questions

Can I drive a car that is overheating?

Only long enough to stop safely. Continued driving can cause severe damage.

Can low coolant cause overheating?

Yes. It is one of the most common causes.

Why does my car overheat only in traffic?

Cooling fan or airflow issues are common suspects.

Is overheating expensive to fix?

Sometimes no, sometimes yes. A hose leak is very different from head gasket damage.