Why Is My Car Overheating? Stay Safe During The Summer Heatwave

There's no doubt about it – we're enjoying one of the hottest and longest summers the UK has seen in years. While many of us are making the most of the sunshine with road trips, holidays and days out, the soaring temperatures are also putting extra strain on our vehicles.

At Foster & Heanes, we've already seen an increase in enquiries from motorists whose cars are running hotter than normal or have overheated completely.

If your temperature gauge is creeping into the red, or steam starts escaping from under the bonnet, it's important to know what to do next.

In this guide, we'll explain what causes a car to overheat, how to reduce the risk, and what to do if it happens to you.

Why Do Cars Overheat?

Your engine works incredibly hard every time you drive. It relies on the cooling system to keep it operating at the correct temperature. When any part of that cooling system isn't working properly, excessive heat can quickly build up.

Hot weather makes the problem even worse, especially if you're:

Sitting in slow-moving traffic
Towing a caravan or trailer
Driving up long hills
Carrying a fully loaded car
Travelling long distances

These conditions force your engine to work harder while receiving less airflow to cool it.

The Most Common Causes of an Overheating Car

Low Coolant Levels

One of the biggest causes of overheating is simply having insufficient coolant. Coolant circulates through the engine, absorbing heat before releasing it through the radiator. If levels are low because of evaporation or a leak, the engine can't cool itself effectively.

Coolant Leaks

Leaks can develop from:

Radiator hoses
Water pump
Radiator
Expansion tank
Pipe joints

Even a small leak can eventually cause serious overheating.

Faulty Thermostat

The thermostat controls coolant flow around the engine.

If it sticks closed, coolant can't circulate properly and the engine temperature rises rapidly.

Radiator Problems

Over time, radiators can become:

Blocked internally
Damaged by road debris
Corroded
Restricted by dirt and insects

A blocked radiator simply can't remove heat efficiently.

Cooling Fan Failure

When you're driving at speed, air naturally flows through the radiator. In slow traffic, your electric cooling fan takes over. If the fan isn't working, temperatures can quickly rise on hot days.

Water Pump Failure

The water pump keeps coolant moving around the engine. If it begins to fail, circulation slows and overheating follows.

Warning Signs Your Car Is Getting Too Hot

Keep an eye out for:

Temperature gauge climbing higher than normal
Temperature warning light
Steam from under the bonnet
Sweet smell of coolant
Loss of engine power
Knocking or unusual engine noises

The sooner you react, the less chance there is of expensive engine damage.

What Should You Do If Your Car Overheats?

First of all - don't panic.

If it's safe to do so:

1. Turn Off the Air Conditioning

Air conditioning places extra load on the engine. Turning it off can help reduce heat.

2. Turn the Heater On

It may sound strange on a hot day but putting the heater on full can help draw excess heat away from the engine.

3. Pull Over Safely

If the temperature continues to rise or warning lights appear, pull over somewhere safe as soon as possible. Do not continue driving if the engine is overheating.

4. Switch Off the Engine

Allow the engine to cool naturally. Opening the bonnet carefully (once safe) can help heat escape more quickly.

5. Never Remove the Radiator Cap

This is one of the biggest mistakes drivers make. The cooling system is under enormous pressure. Removing the cap while hot can release boiling coolant and cause serious burns.
Always wait until the engine has completely cooled.

Can I Keep Driving?

In most cases…no.

Driving an overheating vehicle can cause:

Blown head gasket
Warped cylinder head
Engine seizure
Complete engine failure

What might have been a relatively inexpensive repair can quickly become a bill worth thousands of pounds.

How to Prevent Your Car Overheating

Fortunately, prevention is usually straightforward. Check coolant levels regularly, especially before long journeys. Always use the correct coolant specified for your vehicle.
Book regular servicing. Routine servicing allows technicians to spot small leaks, worn hoses, cooling system faults and failing water pumps before they become major problems.

Watch Your Temperature Gauge

Most drivers never look at it until there's a problem. If you notice temperatures creeping higher than usual, have the car checked.
Don't ignore the warning lights! Your car is trying to tell you something. The sooner you investigate, the cheaper the repair is likely to be.

Make Sure Your Cooling System Is Healthy

A simple inspection can identify:

• Low coolant
• Radiator condition
• Cooling fan operation
• Hose condition
• Pressure leaks

giving you complete peace of mind before summer holidays.

Broken Down Nearby?

While Foster & Heanes doesn't generally provide a vehicle recovery service, if you've broken down locally to one of our Fleet or Dogmersfield garages, there may be occasions where we're able to help recover your vehicle.

If you're stranded nearby, please give us a call on 01252 615657. We'll do our very best to help or advise you on the most appropriate course of action.

Stay Cool and Keep Moving This Summer

The sunshine is fantastic - but it can be tough on your vehicle. A little preventative maintenance now could save you from an overheated engine, an expensive repair bill and a ruined day out.

If you're planning a summer holiday, a long road trip or simply want the reassurance that your cooling system is in good health, book your vehicle in with Foster & Heanes.

Our friendly, experienced team is always happy to help keep you and your car safely on the road.

📞 Call 01252 615657 today to book your cooling system check, service or repair.

Foster & Heanes – Trusted Car Servicing, Car Repairs, Diagnostics and MOTs in Fleet & Dogmersfield.