The causes of the fault are complex and the forms are various, which are mainly shown as follows:
1. The cooling water is not circulating smoothly, which leads to poor heat dissipation and high water temperature
The cooling system is leaking or not enough added, which causes the insufficient coolant quantity. The thermostat fails to work, the coolant can not be circulated for a long time, and the water temperature rises sharply after a long time of operation, which is most obvious in summer. As the key component of engine cooling system, when the pump is not working normally, it will also lead to poor heat dissipation and make the water temperature too high. If the pump is completely inoperative, it is easy to diagnose and deal with, and the pump blade is damaged, it is difficult to check and judge. When the coolant or hard water is not used, the scale can directly block the water jacket of cylinder head, the water hole of cylinder pad, radiator channel or engine block channel, so that the cross-sectional area of the channel is abnormally reduced, which causes the circulation of the coolant to be blocked. The specified coolant or hardened water must be used in the use.
2. Insufficient air inlet volume of cooling system, resulting in poor heat dissipation and high water temperature
When the fan belt is aged, stretched, adjusted improperly or the blade is damaged, the fan speed is not enough and the cooling air is not enough to cool the radiator. When the engine damping rubber pad is aged and damaged, the engine fan will sink, which will cause the fan to deviate from the relative position between the radiator and the cooling radiator. When the outer gap of the cooling radiator is blocked by oil or dust, the air intake is not enough to cause poor heat dissipation. This phenomenon is most common in tunnel construction, so the sealing between water tank and hydraulic oil radiator should be avoided, To prevent damage to its sealing performance.
