21 There is insufficient engine cooling
1. Reduced level of coolant in the system (Chapter 1).
2. Incorrect adjustment or damage to the coolant pump drive belt (Chapter 1).
3. The radiator honeycombs are clogged or the grille is blocked (chapter 3).
4. Thermostat malfunction (chapter 3).
5. Damage or bending of the radiator fan blades (chapter 3).
6. Inability of the expansion tank cap to maintain the required pressure in the system. Check the control pressure of the cap by contacting the station.
7. Malfunction of the radiator fan electrical circuit (chapter 3).
22 Excessive engine cooling occurs
1. Thermostat malfunction (chapter 3).
2. Malfunction of the coolant temperature sensor (chapter 12).
3. Malfunction of the radiator fan electrical circuit (chapter 3).
23 There is an external coolant leak
1. Damaged or destroyed hose. The hose clamps are loose. Replace the hose and/or tighten the clamps (Chapter 1).
2. Failure of the cooling system pump seals. In this case, coolant will flow out of the drain hole in the pump housing (chapter 3).
3. Fluid leaking through the radiator or side reservoir. To restore, you need to contact a radiator repair shop (the removal procedure is described in chapter 3).
4. Leakage from the drain plug or cooling jacket plug (Chapter 2B).
5. Leakage through the heater heat exchanger. Signs of such a leak may be found in the interior carpeting (chapter 3).
24 There is an internal coolant leak
Note: An internal coolant leak is usually detected by inspecting the engine oil. Make sure there are no drops of fluid or oil emulsion on the dipstick and the inside of the valve cover.
1. Leaking cylinder head gasket. Measure the operating pressure in the cooling system.
2. Crack in the cylinder surface or block head. Remove the cylinder head and inspect (chapter 2).
25 There is a drop in coolant level
1. Exceeding the permissible fluid level in the expansion tank (Chapter 1).
2. Liquid boils away due to engine overheating (see subsection 15).
3. There is an internal or external fluid leak (see _ subsection 23 and 24).
4. Failure of the radiator cap. Check the operating pressure of the cap.
26 There is insufficient coolant circulation
1. Failure of the cooling system pump. To perform an instant check while the engine is idling, squeeze the upper radiator hose with your hand and then quickly release it. If the pump is working properly, you should hear a splash of coolant (Chapter 1).
2. Cooling system channels are clogged. Drain the coolant, flush the system and refill it (Chapter 1). If necessary, remove the radiator (chapter 3) and perform a countercurrent rinse.
3. Failure of the drive belt or tensioner (Chapter 1).
4. Thermostat jammed (chapter 3).