During the operation of the car, situations occur when the temperature of the coolant begins to rise rapidly to critical values bordering on engine overheating. In this case, it is recommended to turn on the stove at full power, stop and let the motor cool down. If the pressure in the cooling system is low, it is useful to top up the radiator with water. As soon as possible, you need to find out and eliminate the causes of engine overheating.
The first reason for excessive heating of the motor may be a lack of coolant. It may be the result of a leak in the cooling system. You can detect the fact of leakage by white streaks on the engine and drops of antifreeze under the car after parking. Internal leaks, where coolant flows into the oil and cylinders, are more difficult to detect. And the consequences from it are worse. In addition to the danger of overheating, the danger of water hammer and crankshaft seizure is added.
The second reason may be the low efficiency of the radiator fan. The low productivity of its work may be due to the weakening of the tension of the belt of its drive or due to the incorrect operation of the temperature sensor. It is also possible that the fins of the radiator are heavily contaminated, especially in the summer in those regions where there are many poplars.
The third reason is a malfunction of the thermostat. At the same time, it freezes in one of two positions, and the coolant constantly begins to circulate only in a large circle, or only in a small one. In the first case, the motor begins to more difficult to gain operating temperature, in the second, it constantly overheats. The reason for the failure of the thermostat can be hard water with a high content of salts and minerals, or the abuse of sealants for the cooling system.
The fourth reason is incorrect adjustment of the ignition or injection system. Late ignition can lead to a sharp rise in the temperature of the exhaust gases, the increased heat from which will be transferred to the cylinder head. Prolonged operation of the engine under conditions of detonation leads to increased wear of the parts of the power unit.
The fifth reason is the long-term operation of the engine under conditions of increased loads. The cooling efficiency of the engine directly depends on the crankshaft speed. Therefore, in traffic jams, when the cooling system at low speeds is ineffective, when there is almost no oncoming flow rate, and it is also hot outside, the probability of excessive heating of the engine is almost one hundred percent.
The sixth reason is a burnt out exhaust valve. The presence of a crack on it increases the temperature of the exhaust gases, and therefore of all engine parts.
The seventh reason is the accumulation of deposits in the cavities of the cooling system. Deposits are formed from mineral salts released from the coolant. When they accumulate, they block the channels and interfere with heat removal. In this case, the coolant temperature gauge may not respond to the emerging internal overheating. In addition to the above, the deposits cause cavitation of the cooling cavities up to the appearance of through holes in the system.
The eighth reason is deposits in the combustion chamber. Accumulating, they kind of insulate it. Often this phenomenon occurs in worn-out engines: a lot of oil enters the cylinders, which forms deposits on the cylinder walls. The resulting overheating of the combustion chambers leads to an even greater oil consumption and an increase in this phenomenon. As in the previous case, the temperature gauge will not show an increased heating of the motor. Signs by which one can judge about the presence of deposits in the combustion chambers are a slow reaction of the engine to pressing the gas pedal, blue smoke from the exhaust pipe, problems with starting the power unit.
The final cause of engine heat build-up is the abuse of engine oil additives. Additives that build up the cermet layer on the cylinder surfaces simultaneously contribute to the appearance of an effect similar to that which manifests itself when deposits accumulate on the cylinder walls.
