Thermostat: Service and Repair

Removal Procedure

Caution: In order to help avoid being burned, do not remove the radiator cap while the engine and the radiator are hot Scalding fluid and steam can be blown out under pressure if the cap is removed too soon.

1. Drain the engine coolant. Refer to Draining and Filling Cooling System.





2. Remove the radiator hose clamp from the thermostat housing (1).





3. Remove the radiator hose from the thermostat housing.





4. Remove the three bolts and the thermostat housing (3) from the intake manifold.
5. Remove the thermostat and the O-ring from the thermostat housing.
6. Clean any corrosion or debris from the thermostat housing.
7. Clean the intake manifold mating surfaces.
8. Inspect the thermostat. Refer to Thermostat Diagnosis.

Installation Procedure

Important: Position the air bleed valve on the thermostat toward the top of the engine.

1. Install the thermostat in the described position to the cylinder head.
2. Install a new thermostat O-ring.





3. Install the thermostat housing (3) to the intake manifold.

Notice: Refer to Fastener Notice in Service Precautions.

4. Secure the thermostat housing (3) with three bolts.
^ Tighten the thermostat housing bolts to 16 Nm (12 ft. lbs.).





5. Install the radiator hose and clamp to the thermostat housing (1).
6. Fill the radiator with approved coolant. Refer to Draining and Filling Cooling System.
7. Start the engine.
8. Allow the coolant to attain operating temperature (both hoses feel warm and the coolant is flowing through the radiator).
9. Check for leaks in the cooling system.
10. Shut off the engine.
11. Install the radiator cap.