If your temperature warning light is on, it means your engine is running hotter than normal or there’s a fault in the cooling system. This light is a critical warning — ignoring it can quickly lead to overheating, engine damage, or complete breakdown. An inspection will determine whether the issue is due to low coolant, a faulty component, or a sensor problem.

What does it mean if the temperature warning light comes on?

The temperature warning light indicates that the cooling system isn’t keeping the engine within safe operating range. This may be caused by an actual overheating problem or an electrical fault with the temperature sensor.

Common causes of a temperature warning light

• Low coolant level due to leaks
• Faulty thermostat
• Failed water pump
• Cooling fan not working
• Blocked or leaking radiator
• Blown head gasket
• Faulty temperature sensor or wiring

Why do you need to fix this problem quickly?

Continuing to drive with the temperature warning light on can cause severe engine damage, including warped cylinder heads, blown head gaskets, or total engine failure. Immediate inspection is necessary to prevent costly repairs.

How do you know when to get it checked?

You should stop driving and book an inspection immediately if:

• The temperature warning light comes on while driving
• You see steam coming from under the bonnet
• You smell coolant inside or outside the car
• The heater stops working properly
• The car loses power when the warning light is on

What happens during an assessment?

A mechanic will:

1. Check coolant levels and inspect for leaks
2. Pressure test the cooling system
3. Inspect the radiator, thermostat, and water pump
4. Check cooling fan operation
5. Scan the ECU for fault codes
6. Confirm whether the issue is mechanical or sensor-related

How much does it cost to fix?

Costs depend on the cause. A thermostat replacement may cost $250–$450. Cooling fan or sensor repairs typically cost $300–$700. Radiator or head gasket repairs can range from $900–$3,000+.

Is it unsafe to drive with the temperature warning light on?

Yes. Driving with the temperature warning light illuminated risks severe and immediate engine damage. If this light comes on, pull over safely, turn off the engine, and arrange for the vehicle to be towed to a workshop.