Thermostat: Service and Repair

Engine Coolant Thermostat Replacement (1.8L)

Removal Procedure

1. Drain the engine coolant. Refer to Cooling System Draining and Filling (Service and Repair).




2. Remove the 2 nuts (1, 2) and water inlet.




3. Remove the thermostat (1) and gasket.
4. Remove the gasket from the thermostat.

Inspection Procedure





Note: The valve opening temperature is inscribed on the thermostat.

1. Inspect thermostat.




2. Immerse the thermostat in water and then gradually heat the water.

Note: If the valve opening temperature is not as specified, replace the thermostat.

3. Inspect the standard valve opening temperature of the thermostat.

Standard valve opening temperature - 80-84°C (176-183°F).





Note: If the valve lift is not as specified, replace the thermostat.

4. Check the valve lift (a).
Standard valve lift: 10 mm (0.394 in) or more at 95°C (203°F)

Note: If it is not fully closed, replace the thermostat.

5. Inspect that the valve is fully closed when the thermostat is at low temperatures, below 77°C (171°F).

Installation Procedure

1. Install the thermostat.
2. Install a new gasket on the thermostat.





Note: The jiggle valve (1) may be set to within 10 degrees on either side of the indicated position.

3. Install the thermostat to the water inlet with the jiggle valve (1) upward.





Caution: Refer to Fastener Caution (Fastener Caution).

4. Install the water inlet with the 2 nuts (1, 2) and tighten to 10 Nm (7 lb ft).
5. Add the engine coolant. Refer to Cooling System Draining and Filling (Service and Repair)
6. Inspect for coolant leaks. Refer to Cooling System Leak Testing (Component Tests and General Diagnostics).