Your car’s engine naturally generates a lot of heat while it runs, which is why it relies on a cooling system to keep temperatures under control. Most of the time this system works quietly in the background without you even needing to think about it.
However, on longer drives, during hot weather or in slow-moving traffic, you may notice your engine temperature starting to climb. If this happens, knowing how to respond can help you deal with the situation safely, and reduce the risk of potential damage.
With this guide you’ll learn how to recognise the signs of an overheating engine, what steps to take if it happens while you’re driving, and when it may be best to seek help.
Quick guide: how to handle an overheating engine
If you think your car may be beginning to overheat while you’re driving, you should:
- Turn off the air conditioning to reduce strain on the engine
- Turn the heater on to help draw heat away from the engine
- Pull over to a safe place as soon as you can
- Switch off the engine and allow it to cool down
- Once the engine has cooled, check coolant levels or arrange assistance if needed
These steps can help bring your engine temperature down, and give you time to assess the situation safely.
How to recognise the signs of an overheating engine
Most cars will give some warning before the engine becomes too hot, so you’ve got time to do something about it.
One of the most common signs is that the temperature gauge on your dashboard is rising higher than usual. There may be a temperature warning light that turns on if the engine temperature reaches a critical level.
You might also notice steam coming from the bonnet, unusual sounds, or a slight burning smell from the engine bay. In some cases, the car may begin to lose power and start to feel sluggish to drive.
How to respond when your car engine overheats
If you think your car’s engine is overheating, or the temperature warning light has come on while you’re driving, it’s important to stay calm but act quickly.
Get to safety
First, signal and pull over to a safe place at the side of the road as soon as you can. If you’re driving on a motorway or a very busy road, take the next available exit or pull into a service station if possible.
Reduce strain on the engine
As you’re pulling over and slowing down, try to reduce any strain on the engine by turning off any extras, like air conditioning, that make your car work harder.
Cool down the engine
To start cooling your engine down, turn on your heater (yes, really). While hot air may seem like the last thing you need in an overheating car, starting your heater can actually help in this situation. Turning your temperature to high and setting the fan to full can help draw heat away from the engine and cool it down slightly, dispelling the heat into the cabin instead.
Once you’ve stopped in a safe place, switch the engine off immediately. If you’re near a busy road, make sure to follow safety guidelines for stopping at the roadside and keeping passengers calm. Most importantly, make your vehicle and passengers as visible as possible (high-vis jackets are essential if you have them), get out of the vehicle safely through the doors furthest away from the road, and call for help.
Wait for the engine to cool. If you’ve been driving for a while, your engine and bonnet area will be far too hot to inspect straight away, so avoid touching the bonnet or engine parts. Leave it at least 30 minutes before attempting to open your bonnet, and protect your hands if necessary.
Check the coolant levels
Once the engine has cooled, you can check your engine coolant levels. This is usually a translucent white plastic container with “Min/Max” markings on the side. If the road is particularly busy, it’s dark, or you don’t feel safe or confident inspecting your engine yourself, call a breakdown provider for help.
- If the coolant levels are below the minimum level, you’ve likely run out unexpectedly or you’ve got a leak. If you have coolant with you and your engine is cold enough, you can top up the container yourself. Don’t pour coolant into the tank if it’s still warm.
- If your coolant levels look ok (between minimum and maximum markings), your engine is overheating for another reason and likely requires professional attention.
Call for help
Knowing when to call in the breakdown experts can be tricky. As a rule of thumb, it’s best to get professional help if you feel unsafe, aren’t comfortable checking over your car yourself, or are still encountering issues even after cooling your engine and checking the coolant.
You may need assistance if:
- The temperature warning light stays on
- Coolant is leaking from the vehicle
- Steam continues to appear after cooling
- The engine overheats again shortly after restarting
If your vehicle can’t continue safely, a recovery service can help arrange transport to a nearby garage for inspection and repair.
Can you still drive your car if it overheats?
Whether you’re able to get back on the road after your car overheats depends on the engine temperature, and the reason for overheating.
Yes
If you’ve successfully cooled down your engine to a normal temperature (i.e., the temperature gauge has returned to its normal position) and your coolant levels are correct, it may be possible for you to drive a short distance.
That said, you should keep a close eye on your car when attempting to drive after an overheating episode, looking out for the common warning signs like steam, smells, and warning lights.
No
If your engine is still hot after a while, the temperature gauge immediately rises after starting the engine again, or steam continues to appear, then you shouldn’t attempt to drive further. At this point, you should call for help and arrange roadside assistance so the experts can take a closer look at your car.
Does overheating damage your car’s engine?
An overheating engine alone shouldn’t cause any lasting damage to your car, so there’s no need to worry, especially if you follow the steps above and fix the problem quickly.
Continuing to drive with an overheated engine, however, does risk causing further damage to your car. If you don’t top up your engine coolant or ignore the dashboard warning light, you put your engine under unnecessary stress – and increase the chances of causing harm to its components.
Does breakdown cover include overheating engine problems?
If your car can’t continue due to an overheating engine, breakdown cover may be able to help.
While every policy is different, breakdown cover often includes roadside assistance to help you continue your journey or provides recovery to a nearby garage where the problem can be investigated further.
The exact level of support will vary, so it’s worth checking what your breakdown cover includes before setting off on longer journeys.
Stay cool, calm, and collected
If your car begins to overheat while you’re driving, staying calm and responding quickly can help keep the situation under control. Pulling over safely, allowing the engine to cool, and checking the basics are the first steps to helping you get back on the road.
In many cases, the issue can be resolved once the vehicle has cooled down. But if the temperature continues to rise, or you’re unsure about the cause, arranging assistance is usually the safest option.
For more motoring guidance, keep up with the Green Flag blog.
There is a lot you can do if your car’s engine overheats. First pull in and stop. Next find a large cloth or similar. Pull the bonnet release. Touch the bonnet area to see if it is hot. If it is hot, wrap the cloth around the hand and prepare to open the bonnet. A bit of hot metal is hardly the most dangerous thing in the world. Stand back as you open the bonnet. The steam will blow away.
Then look to see where the steam is coming from. Once the steam has stopped escaping, place the cloth over the coolant reservoir cap and very slowly release the cap a fraction. Any pressure in the system will be released, and you are left with only the hot coolant left in the system.
Hose fittings may need retightening. You can then refill the system, if it is intact. But do so very slowly, a few drops at a time, to prevent the cool water from boiling and bubbling back out. If you do not have plain water with you, or you cannot get plain water, and depending on the situation then perhaps cool drinks might be used as a temporary solution.
If you have had a fan belt failure, an old trick was using a ladies’ stocking in its place. A hole in the radiator can be filled with Radweld – always carry a can.
Regrettably few cars these days have temperature gauges, so the driver cannot tell when the engine is starting to get too hot. But driving gently to when the system can be refilled completely with plain water is one option. Once home, drain and flush the system and refill it with proper coolant to prevent future freezing.
And always carry a five litre can of water in the boot in case of overheating.
In the past few decades, nearly every problem I have had with my (older) cars repeatedly overheating, despite all the normal checks ( hoses, fluid, radiator, thermostat, water pumps, fans etc), the underlying cause has been the engine coming to the end of its life due to wear. Big ends going, blown head gaskets, cylinder wear all seem to have been diagnosed by garages. The honest ones tell you the car needs scrapping and replacing. The less honest ones try to fix the faults at great cost. Know when to stop nursing that beloved but repeated overheating old banger- send it to that great scrapheap in the sky! The alternative is a sudden catastrophic and unfixable engine failure,often on a motorway or in the middle of nowhere.
If your car is prone to over heating on steep hills, a tip is to open the windows and turn on the heating to divert coolant via the heater matrix which contains on average 2 to 3 letters plus what in the pipe system.Note put the heating on slowly so a to avoid the sudden extra presure serge on the system.