To check the thermostat on a car, start the cold engine and touch the right (outlet) radiator hose with your hand - it should be cold. After the coolant temperature reaches 60°C, the hose should begin to heat up quickly, which indicates that the liquid has begun to circulate through the large circuit. If this does not happen, and the coolant temperature sensor and engine control unit are in good condition, replace the thermostat.
You will need: a 10 mm socket head and sliding pliers.
1. Disconnect the wire from the negative terminal of the battery.
2. Drain the fluid from the engine cooling system (see "Replacing the coolant").
3. Remove the generator (see "Removing and installing the generator").
Fig. 5.23. Thermostat: 1 – radiator outlet hose; 2, 6, 8 – clamps; 3 – thermostat housing mounting bolts; 4 – thermostat housing sealing gaskets; 5 – thermostat housing; 7 – hose to the water jacket outlet pipe; 9 – liquid hose of the expansion tank; 10 – Thermostat wiring harness connector
4. Using sliding pliers, loosen clamps 2, 6 and 8 (Fig. 5.23), slide the clamps along hoses 1, 7, 9 and remove the hoses from the thermostat housing pipes.
5. Disconnect connector 10 of the wiring harness from the thermostat by squeezing its fastening clamp.
6. Unscrew the four bolts 3 securing the thermostat housing to the cylinder block and remove the thermostat.
7. Remove the sealing gaskets 4 from the thermostat housing.
CAUTION: Replace the thermostat housing seals with new ones each time the thermostat housing is removed.
8. Install the parts in the reverse order of removal. Tighten the thermostat housing mounting bolts evenly crosswise to a torque of 9.0 N·m.
9. Fill the engine cooling system with liquid and remove air from it (see "Replacing the coolant").