My Car Overheated on the Road: What Should I Do?

If your car overheats while driving, pull over somewhere safe, switch off the engine and let it cool down. Do not continue driving with the temperature gauge in the red zone or an engine temperature warning light on. Doing so can cause serious engine damage. Most importantly, never open the radiator cap while the engine is hot because pressurised coolant or steam can cause severe burns.

How to tell if your car is overheating

Your car may show several warning signs before or during an overheating incident.

Look out for these signs:

• Temperature gauge enters the red zone: The engine temperature is higher than its normal operating range.
• Engine temperature warning light appears: A warning light or dashboard message tells you the engine is too hot.
• Steam comes from under the bonnet: This may indicate that coolant is boiling or leaking.
• Coolant smell: You may notice a sweet smell from leaking engine coolant.
• Loss of engine power: The car may feel weak, struggle to accelerate or make unusual knocking sounds.

If you notice any of these signs, do not ignore them. Find a safe place to stop as soon as possible.

What to do when your car overheats while driving

Follow these steps to protect yourself and prevent further engine damage.

Step	What you should do
1. Turn off the air conditioning	Switch off the A/C to reduce the load on the engine while you look for a safe place to stop.
2. Pull over safely	Move away from traffic and stop at a safe location. Avoid stopping in a dangerous spot or blocking the road.
3. Switch on hazard lights	Alert other drivers that your vehicle has a problem.
4. Turn off the engine	Once safely stopped, put the car in Park (P), apply the parking brake and switch off the engine.
5. Keep a safe distance	If you see steam or smoke, do not open the bonnet. Keep away from the engine compartment until it is safe.
6. Let the engine cool	Wait until the engine has cooled completely before checking the coolant level. This may take 30 minutes or longer.

If you are on a highway, prioritise your safety. Move away from moving traffic if it is safe to do so, and contact the highway operator or roadside assistance for help.

You can also read our guide on what to do if your car breaks down on the highway.

Can I open the radiator cap when the engine is hot?

No. Never open the radiator cap or coolant reservoir cap while the engine is hot.

The cooling system is pressurised when the engine is running and may remain hot after you switch it off. Opening the cap too soon can release boiling coolant or steam, causing serious burns.

Wait until the engine has cooled completely before checking the coolant level. Follow your car manufacturer’s instructions when inspecting or topping up the coolant.

If you notice coolant leaking, a very low coolant level or steam coming from the engine compartment, do not attempt to continue your journey. Arrange professional assistance instead.

What should I check after the engine cools down?

Once the engine is completely cool, you can look for obvious signs of a cooling system problem.

What to check	What it may indicate
Coolant level in the reservoir	A level below the MIN mark may indicate insufficient coolant.
Puddles under the car	A coloured or unusual liquid may be a sign of a coolant leak.
Radiator hoses	Cracks, loose connections or visible leaks may affect coolant circulation.
Radiator and coolant reservoir	Visible damage or leaks may prevent the cooling system from working properly.

Do not touch hot engine components, moving parts or electrical connections. If you are unsure how to inspect the cooling system, leave it to a qualified mechanic.

Can I add water to the radiator?

Some vehicle manuals allow water as a temporary emergency measure if coolant is unavailable. However, this is not a substitute for the correct coolant. Follow your vehicle manufacturer’s instructions and have the cooling system checked as soon as possible.

Do not pour cold water into a hot engine or open the radiator cap to refill it while the system is still hot.

Can I continue driving after my car overheats?

It is safer not to continue driving if your car has overheated. Even if the temperature gauge returns to normal after cooling down, the underlying problem may still be there.

Restarting the engine and continuing your journey could cause the temperature to rise again, potentially leading to expensive repairs.

Arrange for your car to be inspected or towed to a workshop, especially if:

• The temperature warning light remains on or comes back.
• Coolant is leaking from the vehicle.
• Steam continues to come from the engine compartment.
• The engine makes unusual noises or loses power.
• The coolant reservoir is empty or repeatedly loses coolant.

Only consider driving again if the cause has been addressed and your vehicle manufacturer’s instructions indicate that it is safe to do so.

What causes a car engine to overheat?

An engine can overheat when its cooling system cannot remove heat effectively. Several components may be responsible.

Possible cause	How it affects the engine
Low coolant level	There may not be enough coolant to absorb and transfer engine heat.
Coolant leak	A damaged hose, radiator or connection can cause coolant loss.
Faulty radiator fan	The fan may not provide enough airflow to cool the radiator, especially when the car is stationary or moving slowly.
Faulty thermostat	A thermostat that does not open properly can restrict coolant circulation.
Damaged water pump	The pump may fail to circulate coolant through the engine.
Blocked radiator	Dirt or internal deposits can reduce the radiator’s ability to release heat.

A mechanic can inspect the cooling system to identify the actual cause. Do not assume that adding coolant will solve the problem, as an underlying leak or faulty component may still need repair.

Does car insurance cover engine overheating?

Standard comprehensive car insurance does not usually cover mechanical breakdown caused by engine overheating. Damage resulting from wear and tear, poor maintenance or mechanical failure is generally not covered, subject to the policy wording.

However, some insurance policies provide roadside assistance or towing benefits. These may help you arrange transport to a workshop if your car breaks down.

Before requesting a tow, check:

• Whether your policy includes roadside assistance.
• The towing distance limit and any additional charges.
• Whether you need to contact the insurer’s assistance hotline first.
• Whether the service covers mechanical breakdown, rather than accidents only.

You can compare car insurance options on BJAK and check the coverage and assistance benefits offered by the available providers.

Conclusion

If your car overheats, do not risk driving it further just to reach the nearest workshop. Stop safely, let the engine cool and arrange professional assistance if needed. A tow may cost less than repairing an engine damaged by continued overheating.