The need to remove the thermostat may arise to replace it when the engine temperature is unstable: overheating or insufficient heating.
To check the thermostat on a car, start a cold engine and touch the lower (diverting) radiator hose - it should be cold. After the coolant temperature reaches 90–95°C, the hose should begin to heat up quickly, indicating the start of fluid circulation in the large circuit. If it doesn't, remove the thermostat and replace it.
You will need a key «on 10».
1. Drain the coolant (see «Coolant replacement»).
2. Turn out three bolts of fastening of a cover of the thermostat.
3. Pull back the lid...
4.... and remove the thermostat from the cover.
5. Remove the O-ring from the thermostat and inspect it. Replace a severely compressed, hardened or torn ring.
6. Install the O-ring on the new thermostat.
7. Install the parts in the reverse order of removal.
8. Fill in coolant and remove air pockets from the cooling system (see «Coolant replacement»).