The temperature of the coolant is too high, the arrow of the temperature gauge is in the red range, the control lamp is on
Too little coolant in circulation system
The fluid in the expansion tank must be between the marks «MINI» and «MAXI». Top up the liquid if necessary. Check the cooling system for leaks.
The thermostat does not open. Coolant circulates only in the small circuit
Check if the outlet is heating up (upper) radiator hose. If not. remove and check the thermostat. Replace if necessary.
If a thermostat malfunction occurs on the road, then remove the thermostat and continue driving without it. In this case, the coolant will heat up to operating temperature more slowly or not reach it at all. Replace the thermostat with a new one as soon as possible.
Radiator fins dirty
Remove the radiator and blow compressed air from the engine side.
Radiator clogged with lime deposits or rust. The radiator warms up only at the top, the lower radiator hose remains cold
Replace radiator.
Fan blower not working
Check the reliability of the thermoswitch and fan plugs and their contacts.
Attention! Risk of injury from rotating fan.
Check thermal switch. If this defect occurs on the way, bridge the contacts of the thermal switch. The fan will run as long as the ignition is on. As a rule, radiator airflow is necessary when traveling with frequent stops and gear changes or in city conditions.
Check if there is voltage at the electric fan plug. In this case, the ignition must be switched on, the thermoswitch plug must be bridged. If voltage is present, replace the fan motor.
Expansion tank cap defect
Check the cooling system. Check pressure expansion tank cap.
Faulty coolant temperature gauge on instrument panel
Check pointer/pointer sensor.
Faulty water pump
Remove the water pump and check it.
Weak tension of the water pump drive V-belt or it broke (only vehicles with 1.9-/2.0-litre petrol engines)
Check and adjust the V-belt/ribbed belt tension.