To prevent combustion engines from getting too hot during operation, a sophisticated cooling system provides cooling. However, if parts of the cooling system are defective or there is no cooling water, the engine can overheat. In our guide on the subject of engine overheating, we provide many tips and answer all questions.

Why does the engine overheat?

Engines as diesel or petrol engines generate a lot of heat through combustion, which must be dissipated. Every modern vehicle is equipped with a cooling system to cool the engine, as the cooling effect provided by air alone is not sufficient. Instead, cooling water is pumped through the engine and to the radiator in a cooling circuit to dissipate the heat generated.

The cooling system in a car consists of numerous components. These include a fan, for example, which ensures that air flows through the radiator even when the car is stationary, so that heat is reliably dissipated. A thermostat for controlling the cooling circuit, the coolant pump and other components are also part of the cooling circuit. If a part is defective, the engine can overheat.

Overview of common causes for an overheated engine

Numerous causes can be responsible for the engine overheating. In addition to problems with the components of the cooling system, a lack of cooling water can also be the source of the evil. Therefore, the level of the cooling water should be checked regularly.

• Lack of coolant
• Defect of the radiator ventilation
• Thermostat does not open
• Cooling circuit is leaking
• Air in the cooling system

Clear signs of engine overheating

If the temperature of the engine rises, the vehicle alerts the driver to the problem. This is to prevent damage to the car such as engine damage due to engine overheating.

• Temperature display shows increased value
• Coolant light comes on
• On-board computer reports engine overheating

One of the clearest signs of an unacceptable temperature rise is the illumination of the red coolant temperature warning light. At the same time, the coolant temperature display may show a high value if the engine has overheated. Depending on the model, an increased engine temperature is also indicated in the display of the on-board computer.

What motorists should do if their engine overheats

If the water temperature display shows alarming values, or if the red warning light in the cockpit even lights up, quick action is called for. The driver should stop the vehicle at the next possible stop and switch off the engine.

1. Search for a stopping point
2. Switch off engine
3. Open bonnet
4. Wait for the engine to cool down
5. Refill water if required
6. Visit workshop

After the stop, the bonnet can be opened to provide cooling. It may take a while for the engine to cool down, but under no circumstances should cold water be poured over the engine block.

Further procedure in case of engine overheating

The radiator cap or expansion tank cap should not be opened without special precautions, as the cooling system may be under pressure and hot cooling water may escape. Instead, a suitable cloth should be used to open the cap after an appropriate cooling period. If cooling water is missing, it can be replenished accordingly.

After the engine has cooled down sufficiently, it is often possible to drive the vehicle to the nearest workshop. However, you should keep an eye on the temperature gauge. If the engine overheats again, the car should be towed away. The workshop can find out the cause of the engine overheating and initiate appropriate repairs.

This is what happens when driving with an overheated engine

If the engine overheats and the car is still moved, this can cause considerable damage. This can affect the cylinder head or the engine block. It is not uncommon for the result to be a major engine failure, the repair of which incurs considerable costs and requires special tools. Often, even a replacement engine is due.

Engine overheating – these parts on the car may be defective

If engine overheating occurs, various components of the cooling system are possible causes. A lack of coolant is often caused by leaks in hoses or connections. A defective cylinder head gasket or a cracked expansion tank can also be responsible for the gradual loss of coolant.

Defective water pumps, damaged radiators or broken radiator fans are also possible reasons for overheating. All parts of the radiator circuit and many engine parts are available second-hand in original quality at Autoparts24. In addition, you can easily compare numerous offers from different car recycling companies.