The engine overheats. Generally speaking, the cooling water temperature in the engine block is too high. There are two common causes of overheating of excavator engine, namely, the decline of heat dissipation capacity and excessive heat load. This page summarizes some causes and troubleshooting methods of excavator engine overheating for reference only.
The reasons for the decline of heat dissipation capacity caused by overheating of excavator engine are as follows:
(1) Insufficient cooling water
Cooling water is the carrier of heat in the cooling circulation system, that is, the heat dissipation to be taken away from the engine body is taken away and distributed by the carrier of water. If the coolant of the cooling system is reduced due to leakage or evaporation, the heat naturally taken away from the engine body will be reduced, resulting in excessive heat accumulation in the engine, that is, the engine is overheated. The main reasons for the decrease of cooling water are as follows:
① Leakage
Water leakage in the cooling system is often seen in the damage of the water seal of the water pump, the rupture of the pipe or the loose connection of the joint, the water leakage due to the damage of the radiator, the damage or lax closing of the drain switch, the water leakage of the heater equipment, etc., which will reduce the cooling water in the cooling system and cause the engine to overheat.
② Evaporate
The evaporation of water in the cooling system affected by temperature will also reduce the cooling water in the system. If the supply is not timely, the result is the same as above.
(2) Poor heat dissipation
① Influence of radiator
After the radiator has been used for a long time, the scale inside the radiator is thickened accordingly. Due to the poor heat transfer capacity of scale, the heat dissipation will be poor.
② Radiator vent blocked
When the engine is working, the dust will flow through the radiator with the air due to the action of the fan. When dust adheres to the flat tubes and fins of the radiator, it not only reduces the air circulation section of the radiator, but also causes poor heat dissipation due to poor thermal conductivity due to dust and dirt.
③ Fan belt slipping
The cooling intensity of the water cooling system depends on the fan speed. If the fan drive belt slips due to too loose, it will reduce the power transmission efficiency, which will not only reduce the fan speed and cooling intensity, but also reduce the pump speed and displacement, so that the cooling water flow speed is slow and can not take away the heat quickly, that is, poor heat dissipation.
④ Influence of cooling intensity regulating device
Louvers and thermostats are cooling intensity regulating devices. If the cooling intensity regulating device fails or operates improperly, the engine temperature will be too high.
The louver is set in front of the radiator to adjust the ventilation flow of the radiator. When the opening is large, the ventilation volume is large, otherwise when the opening is small. When the shutter is not opened, the flow section of the cooling air is smaller, resulting in an increase in the engine temperature.
⑤ Thermostat damaged
The thermostat is set at the water outlet of the engine to adjust the cooling intensity, that is, when the engine temperature is low, cut off the large circulating water circuit and connect the small circulating water circuit, so as to reduce the heat dissipation and quickly increase the engine temperature; When the engine temperature rises to the specified temperature, the thermostat will connect the large circulating water circuit and close the small circulating water circuit. If the thermostat is damaged, the large circulating water circuit cannot be connected, resulting in poor cooling water circulation, so that the heat absorbed by the cooling water cannot be brought to the radiator and the engine overheats.
⑥ Cooling water freezing
When working in winter, the cooling water temperature in the lower chamber of the radiator is very low and easy to freeze. After freezing, the cooling water will not circulate, resulting in excessive cooling water temperature.
