Overheating of the engine is an unpleasant business, which leads to a loss of time and money to resolve this problem. Coolant leakage is the simplest and most common cause.
A timely check of the liquid level in the system is necessary, if a shortage is found, all joints should be inspected, passing through the cooling system circuit.
The second reason is the failure of the thermostat; it may not let hot liquid pass into the radiator. If the radiator turns out to be cold after 10 minutes of operation, you need to remove the thermostat and put it in hot water (80 degrees), at this temperature it should open (the thermostat does not work, a replacement is needed).
The third reason is the clogging of the cooling system or the radiator itself. This can be caused by the formation of scale on the tubes (from the use of hard water containing various salts in its composition) or the ingress of foreign objects into the system.
The formation of scale reduces the cooling of the engine, which in this case overheats, the viscosity of the oil decreases, which leads to poor lubrication of the parts. Detonation begins, fuel consumption increases. Pour soft water (rain, distilled, from mountain rivers). Marine or unpaved - hard. Trisodium phosphate or soda ash should be added to soften . There are many tools available to fix this problem.
If scale is formed, the entire system must be flushed with any descaler.
It happens that the thermostat and coolant are normal, and the engine is warming. In this case, it may be that the hose going to the pump is not tightly fastened (it is necessary to replace the clamp with a narrower one so that the hose is pressed closer to the fitting). This failure is typical for cars Moskvich 2140.
Zaporozhets have poor cooling with oncoming air. In this case, various deflectors, air intakes, fans are installed.
In some machines, the principle of cooling itself is based on the movement of the coolant in a large and small circle. While the engine is cold, fluid circulates in a small circle. When warming up, the thermostat opens and circulation begins in large part (through the radiator). The thermostat may not open and liquid will not be allowed to access the large circle. Overheating of the VAZ 2108, 2109, 2199 engine can occur precisely for this reason. To check the operation of the thermostat, you need to warm the engine to 90 degrees and touch the pipe leading to the radiator. If the thermostat does not work, the pipe will be cold.
Overheating of the engine can occur from contamination of the outer surface of the cylinders. To clean them, remove the carburetor and cut the casing that covers them.
Overheating of the engine may occur due to a malfunction of the water pump, failure of the drive (if the belt breaks).
This is a serious problem, as a result of which the engine may jam right on the road. Cylinder heads will warp, parts will become deformed due to excess heat. If the engine overheats, the consequences can become irreversible as a result of ordinary carelessness. Check the cooling system before travel, not on the go.