What happens when an engine overheats

When the engine overheats frequently

If the engine overheats: causes, consequences and what to do about it

If the display of your car continuously shows a critical temperature in the red area, then the car is about to overheat without the driver intervening. The consequences are annoying and costly engine damage up to total loss. If the vehicle engine is constantly too hot, a quick reaction is required. Then you shouldn't drive any further, but get in touch with a workshop immediately. On FairGarage you can find out the most common causes of engine overheating. You can find reliable specialist workshops in your area quickly and without obligation.

So that the engine does not overheat

The combustion of the fuel in the engine generates a lot of heat in addition to the drive energy. An internal combustion engine in a car must therefore be constantly cooled when it is in operation. Each vehicle has a temperature indicator on the display to monitor the engine temperature. Various technologies such as the cooling circuit and the fan are used to ensure that the engine temperature of a car never reaches a critical value. One or more thermostats control the engine cooling performance to protect the engine from overheating. If the protective measures provided to prevent the engine from overheating fail, the car can be seriously damaged.

Causes of the engine overheating

If the engine is permanently too hot and there is a risk of overheating, this can have many causes. It is therefore advisable to have the engine checked by professionals in a workshop. We have compiled the most common causes of errors from practice here.

Here are the most common causes of engine overheating:

  • Defective thermostat
  • Air in the cooling system
  • Defective viscous coupling of the fan in longitudinally installed motors
  • Electrical defects in the power supply
  • Road dirt and dirty cooling air intake

Leaky cooling system as the cause of overheating

The car loses coolant due to a leak in the cooling system. The cause can be a leaking hose, a leaking coolant pump, a crack in the radiator or a leak in the engine. Resealing the leak and adding new coolant should resolve the engine overheating problem.

Defective thermostat as the cause of overheating

If the thermostat is defective, only part of the cooling circuit may be used. An engine check and, if necessary, a change of the thermostat can help.

Air in the cooling system as the cause of overheating

The air in the cooling system can also be responsible for the engine overheating. The workshop can ventilate the cooling system if the engine is too hot as a result.

Defective viscous coupling as the cause of overheating

A defective viscous fan can also cause the motor to overheat. The cause is then insufficient fan power because the fan does not engage properly. After checking and, if necessary, installing a new fan, the motor cooling also works again without defects.

Electrical defects as the cause of overheating

Often it is only the small defects in the car's power supply that can bring the engine to a boil. A broken cable, a defective thermal switch, a blown fuse or the complete failure of the fan motor should be mentioned here.

Road dirt as a cause of overheating

Normal street dirt can also cause the engine to overheat. Professional cleaning of the entire cooler network can also make this problem disappear again. Incidentally, this also applies to a dirty cooling air inlet on the radiator grille.

Other possible causes of engine overheating

Rather seldom, but still possible in older vehicles, causes such as an incorrectly set ignition or incorrectly set carburetor, a clogged cooling system or a defective water pump.

So that the engine doesn't start to boil

Regular maintenance of the cooling system is essential to avoid overheating of the engine and the possible consequences such as engine damage. All components from the head gasket to the thermal switch to the carburetor are covered by the inspections. But if the temperature display really gets stuck in the red area, the engine must be switched off immediately. With a little luck, the engine can be cooled down a little by switching on the heating. If the workshop is nearby, it is still possible to drive to the workshop. Otherwise, the breakdown service is the safer and, above all, cheaper alternative. At FairGarage you will find workshops near you that will provide you with professional help in such a case.