Thermostat: Service and Repair

REMOVAL

HINT: Removal of the thermostat would have an adverse effect, causing a lowering of cooling efficiency. Do not remove the thermostat, even if the engine tends to overheat.

1. Drain engine coolant.
2. Remove air cleaner cap assembly and air filter.
3. Disconnect ECT switch connector.





4. Disconnect engine wire protector from water inlet and RH cylinder head. Remove the 2 nuts, and disconnect the engine wire protector from the water inlet and cylinder head.





5. Disconnect water inlet pipe from water inlet and LH cylinder head.
a. Remove the bolt, and disconnect the inlet pipe from the water inlet.
b. Remove the O-ring from the inlet pipe.





6. Remove water inlet and thermostat.
a. Remove the 3 nuts, water inlet and thermostat.
b. Remove the gasket from the thermostat.

INSPECTION

NOTE: The thermostat is numbered with the valve opening temperature.:

HINT: The thermostat is numbered with the valve opening temperature.





a. Immerse the thermostat in water and gradually heat the water.
b. Check the valve opening temperature.

Valve opening temperature: 80 - 84°C (176 - 183°F)

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





c. Check the valve lift.

Valve lift: 10.0 mm (0.394 inch) or more at 95°C (203°F)

If the valve lift is not as specified, replace the thermostat.
d. Check that the valve is fully closed when the thermostat is at low temperatures (below 40°C (104°F)). If not closed, replace the thermostat.

INSTALLATION





1. Place thermostat in water pump.
a. Install a new gasket on to the thermostat.
b. Align the thermostat jiggle valve with the upper stud bolt, and insert the thermostat in the water inlet housing.

HINT: The jiggle valve may be set within 15' of either side of the prescribed position.

2. Install water inlet. Install the water inlet with the 3 nuts.

Torque: 8 Nm (69 inch lbs.)

3. Install water inlet.
a. Install a new O-ring to the water inlet pipe.
b. Apply soapy water to the O-ring.
c. Connect the water inlet pipe to the water inlet.
d. Install the bolt holding the water inlet pipe to the cylinder head.

Torque: 19.5 Nm (14 ft. lbs.)

4. Install engine wire protector.
5. Connect ect switch connector.
6. Reinstall air filter and air cleaner cap assembly.
7. Fill with engine coolant.
8. Start engine and check for leaks.
9. Recheck engine coolant level radiator.