Engine & Performance
What Does Engine Overheating Look Like?
An overheating engine usually makes itself known in one of a few ways. You might notice steam or smoke rising from under the bonnet, a temperature warning light appearing on your dashboard, or the temperature gauge climbing into the red zone. Some drivers also notice a sweet or burning smell coming from the engine bay.
These signs should never be ignored. An overheating engine can cause serious and costly damage within minutes if the car is kept running.
What Is Causing the Engine to Overheat?
There are several things that can cause an engine to overheat. Below are the most common causes. Only a proper inspection can confirm exactly what is wrong with your car.
Low or Empty Coolant Level
Coolant (also called antifreeze) is the fluid that absorbs heat from the engine and carries it away through the radiator. If the coolant level is too low, there is not enough fluid to keep the engine temperature under control. This is the most common cause of overheating and can happen due to a slow leak or simply because the level has not been checked in a long time. A regular car service includes a coolant level check, which can catch this before it becomes a problem.
Coolant Leak
Even if the coolant reservoir looks full, a leak somewhere in the system can cause the level to drop quickly while you are driving. Common leak points include the radiator, hoses, the water pump, and the head gasket. A sweet smell from the engine bay is often a sign of leaking coolant.
Faulty Thermostat
The thermostat controls when coolant is allowed to flow through the engine. If it gets stuck in the closed position, coolant cannot circulate properly and the engine temperature rises rapidly.
Broken Water Pump
The water pump pushes coolant around the engine and through the radiator. If it stops working correctly due to a worn impeller or a broken belt, coolant cannot move and the engine overheats.
Blocked or Damaged Radiator
The radiator releases heat from the coolant into the air. If it is blocked by debris, corroded, or physically damaged, it cannot do its job and engine temperatures will rise.
Blown Head Gasket
The head gasket seals the engine block and cylinder head together. If it fails, coolant can leak into the engine cylinders or combustion gases can enter the cooling system. This causes rapid overheating and is one of the more serious and expensive faults. White smoke from the exhaust is a common sign.
Low Engine Oil
Engine oil helps to reduce friction and carry heat away from moving parts. If oil levels are critically low, the engine generates more heat than the cooling system can handle, leading to overheating.
Engine & Performance
Is It Safe to Drive?
| What you are experiencing | Is it safe to drive? | What to do |
|---|---|---|
| Temperature gauge creeping above normal | Use caution | Pull over safely when you can and let the engine cool. Check coolant level. |
| Temperature warning light on | Not recommended | Stop as soon as it is safe to do so. Do not keep driving. |
| Steam or smoke coming from the bonnet | Do not drive | Pull over immediately, turn off the engine, and do not open the bonnet straight away. |
| Sweet or burning smell from the engine | Do not drive | Turn off the engine and call for assistance. |
| White smoke from the exhaust | Do not drive | Could be a blown head gasket. Do not restart the engine. Call for recovery. |
| Engine overheating and oil warning light on | Do not drive | Serious risk of engine damage. Stop immediately and call for recovery. |
Engine & Performance
What Should You Do?
1. Pull over and turn off the engine. As soon as it is safe to do so, pull over and switch the engine off. The longer an overheating engine keeps running, the more damage it can cause.
2. Do not open the bonnet straight away. The engine, coolant, and radiator cap will be extremely hot. Wait at least 15 to 20 minutes before opening the bonnet to avoid burns from steam or boiling coolant.
3. Do not remove the radiator cap while hot. Coolant is under pressure when the engine is warm. Removing the cap too soon can cause scalding liquid to spray out. Always wait until the engine is fully cool.
4. Check the coolant level once the engine is cool. If the coolant reservoir is empty or very low, this may be the cause. However, do not simply top it up and drive on without finding out why it was low in the first place.
5. Call First Auto Centre. Give us a call on 020 4539 0131 and describe what happened. Our team can advise you straight away and, if needed, help arrange 24/7 breakdown recovery to our East Ham garage for a full inspection.
6. Get a proper diagnosis. Overheating can have several causes, some minor and some serious. Our mechanics will use car diagnostics to check your coolant system, thermostat, water pump, radiator, head gasket, and oil levels to find the root cause and give you an honest assessment.
Not Sure What Is Wrong?
Let Us Take a Look.
Engine overheating is not something to hope goes away on its own. Bring your car to First Auto Centre in East Ham and our experienced team will inspect the cooling system, diagnose the cause, and give you a clear, honest answer. If you cannot drive the car safely, we offer 24/7 breakdown recovery to get you and your vehicle to us.
Call us on 020 4539 0131 or visit us at 1 Lawrence Road, East Ham, London, E6 1JN.
We are open Monday to Saturday, 09:00 to 18:00.
This page is for general guidance only. Only a physical inspection can properly diagnose an overheating issue. If your engine is overheating, stop driving and call us.
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Your Questions
FAQs
In an emergency, you can add clean water to the coolant reservoir to top it up temporarily, but only when the engine is completely cold. Water alone does not have the same properties as coolant and can cause corrosion over time, so you should get the system properly checked and refilled with the correct coolant as soon as possible.
Wait at least 15 to 20 minutes after turning the engine off before opening the bonnet. The engine and cooling system stay very hot for some time after the car stops, and steam or boiling coolant can cause serious burns.
It can, yes. Running an engine at very high temperatures for even a short time can warp cylinder heads, damage seals and gaskets, and in serious cases cause the engine to seize. This is why it is so important to stop the car as soon as you notice signs of overheating.
The head gasket is a seal between the engine block and the cylinder head. If it fails, it can allow coolant and engine oil to mix, or combustion gases to enter the cooling system. Signs include white smoke from the exhaust, a milky appearance to the engine oil, and rapid overheating. A blown head gasket is a serious repair, but catching it early helps avoid further engine damage.
Yes. Even if the engine appears to be running normally again, the underlying cause of the overheating has not gone away. It is important to find out why it happened before it occurs again, potentially causing more serious damage. Our car diagnostics service can identify the root cause even when the car seems to be running normally.
Yes. While oil is not part of the cooling system directly, it plays a big role in reducing friction and carrying heat away from moving engine parts. Critically low oil levels can contribute to overheating, especially in combination with other issues. Oil levels are checked as part of our car servicing.
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Contact Us
- info@firstautocentre.co.uk
- 1 Lawrence Road, Newham, London, E6 1JN
- Mon-Sat: 09:00 - 18:00
- Sunday: Closed
