To check the thermostat on the car, start the engine and touch the lower radiator hose with your hand - it should be cold. After the coolant temperature reaches 85–92°C, the hose should begin to heat up. If this does not happen, remove the thermostat and check its operation.
You will need: hex wrench «by 5», Phillips screwdriver.
1. Remove the plug from the expansion tank. Unscrew the drain plug at the bottom of the right radiator tank and drain the liquid from it (see «Coolant replacement»). Close the drain plug.
2. Loosen the two hose clamps on the nozzles of the thermostat cover...
3.... and remove the hoses from the nozzles of the cover.
4. Turn out three bolts of fastening of a cover...
5.... and remove it together with the thermostat.
Note. Pay attention to the condition of the sealing rubber ring in the groove of the thermostat cover. Replace a severely deformed, torn or loose ring.
6. Overcoming the force of the spring, press the fixing plate of the thermostat down and, turning it in any direction, disengage from the grooves.
7. Remove the thermostat from the cover.
8. Before installing a new thermostat, test it by immersing it in water heated to 78–80°C. Heat the water, stirring constantly, to a temperature (85±2) °C.
9. At temperature (85±2) °С the thermostat rod should begin to move out of the power element. If it doesn't, replace the thermostat.
10. Install the thermostat in the reverse order of removal.
Note. In order to further eliminate the possibility of leakage of coolant, before connecting the hoses to the thermostat cover, lubricate the cover pipes with a thin layer of sealant.
11. Fill the cooling system with liquid (see «Coolant replacement»). Replace the expansion tank cap, start the engine, check for coolant leaks from the thermostat hose connections, and let the engine idle to operating temperature to remove air pockets from the system.