Replacement
1. Drain the coolant (see «Coolant - replacement»).
2. Remove the air filter (see «Air filter - removal and installation»).
3. Using a Phillips screwdriver, loosen the clamps securing the two hoses to the thermostat nozzles.
4. Disconnect the hoses from the thermostat nozzles.
5. With a 5 mm hex wrench, unscrew the three coupling bolts of the thermostat housing.
6. Disconnect the thermostat housing and remove the rubber sealing ring. Replace damaged sealing ring.
7. Having pressed, we turn the thrust plate of the thermostat spring...
... and remove the thermostat actuator from the removed part of the housing.
Comment. You can check the functionality of the thermostat by lowering it into a container of water heated to a temperature close to the boiling point. The valve should open.
8. We assemble and install the thermostat in reverse order.
Removing
1. To remove the thermostat assembly, disconnect the two hoses from the nozzles of the thermostat cover (see paragraphs 1-4 above).
2. Similarly, disconnect three more hoses from the thermostat nozzles.
3. Disconnect the block of wires from the coolant temperature sensor.
4. Using a socket wrench with a deep head of 13 mm, unscrew the fastening nut «mass» wires.
5. Using the same key, unscrew the two nuts securing the thermostat to the cylinder head.
6. Remove the thermostat from the studs and remove the sealing gasket.
7. If necessary, unscrew the coolant temperature sensor (see «Coolant temperature sensor - check and replace»).
Installation
1. Install the thermostat in reverse order, replacing the gasket with a new one.
2. Fill the system with coolant (see «Coolant - replacement»).
3. We make sure that there is no leakage of liquid at the junctions of the hoses with the thermostat. Tighten the hose clamps if necessary.