Engine overheating
The pointer of the coolant temperature gauge is in the red zone at the end of the scale.
Causes of the malfunction and how to fix it:
- lack of coolant or its low level. Pour coolant into the expansion tank and check the tightness of the system;
- the outer surface of the radiator is heavily soiled. Clean the outer surface of the radiator with a water jet under low pressure;
- thermostat is defective. Check the operation of the thermostat, replace if necessary;
- turning off the electric fan. Check the temperature of the coolant at which the contacts of the switch on the electric fan are closed. Switching on should be at 96...102°C. Replace the defective switch-on sensor or electric fan with a new one.
Engine hypothermia
The arrow of the index of temperature of a cooling liquid shows less than 85°C.
The cause of the malfunction and how to fix it:
- defective thermostat (the main valve is constantly open, the liquid circulates constantly in a large circle). Check thermostat operation, replace if necessary.
Coolant leakage
Frequent topping up of fluid in the system.
Causes of the malfunction and how to fix it:
- radiator tube damage. Repair the radiator by installing repair tubes of smaller diameter with their subsequent burnishing (mandrel punching);
- loosening of the hose clamps. Tighten screws, replace if necessary;
- damage to the coolant pump seal. Replace the stuffing box, which requires disassembling the pump. To remove the pump, it is necessary to hang out and partially disassemble the engine. At the removed pump, the toothed pulley 9 is pressed with a puller (see fig. 32) pump, unscrew the locking screw 1 and press out the roller 5 assembled with the impeller 4, the bearing 8 and the stuffing box. Take off the seal. If necessary, press the impeller. When assembling the pump using a mandrel, a new stuffing box is installed without distortion in the pump housing. The roller with the bearing is pressed in so that the seat of the locking screw 1 coincides with the hole in the pump casing. The bearing lock screw is screwed in and the contours of the socket are caulked to prevent loosening of the screw. Then, using the fixture, the impeller 4 and the toothed pulley 9 are pressed in, maintaining the dimensions indicated on rice. 32. Before pressing the pulley, it is heated to 150...200°C.