Engine Coolant Thermostat Replacement 2.2L

1. Remove the necessary amount of coolant from the radiator. Refer to Cooling System Draining and Filling .
2. Remove the thermostat housing mounting bolts.



3. Remove the thermostat housing from the engine.
4. Remove thermostat and O-ring seal.
5. Clean all of the parts.
6. Clean all of the sealing surfaces.

1. Install the thermostat and the O-ring seal to the engine.



2. Install the thermostat housing to the engine.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

3. Install the thermostat housing mounting blots.

Tighten
Tighten the thermostat housing mounting bolts to 10 N·m (89 lb in).

4. Install the upper radiator inlet hose.
5. Fill the cooling system with the specified coolant and concentration. Refer to Cooling System Draining and Filling .
6. Inspect all of the sealing surfaces and the connections for leaks after starting the engine. Refer to Cooling System Leak Testing .

Engine Coolant Thermostat Replacement 4.3L

1. Remove the necessary coolant from the radiator. Refer to Cooling System Draining and Filling .
2. Remove the air outlet duct. Refer to Air Cleaner Outlet Duct Replacement in Engine Controls.
3. Remove the throttle body bracket. Refer to Throttle Body Assembly Replacement in Engine Controls.



4. Remove the thermostat housing mounting bolts.



5. Remove the thermostat housing from the lower intake manifold and set aside.
6. Remove the gasket or O ring.



7. Remove the coolant thermostat.
8. Clean all the sealing surfaces of the coolant outlet.
9. Clean the sealing surface on the lower intake manifold.

Important: In order to prevent leakage, thoroughly clean all parts and sealing surfaces.

1. Install the coolant thermostat.



2. Install a new gasket or O ring.
3. Place the thermostat housing on the lower intake manifold. Ensure the gasket or O ring is in correct position.




Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

4. Install the thermostat housing mounting bolts.

Tighten
Tighten thermostat housing mounting bolts to 19 N·m (14 lb ft).

5. Install the throttle body bracket. Refer to Throttle Body Assembly Replacement in Engine Controls.
6. Fill the cooling system with specified coolant and concentration. Refer to Cooling System Draining and Filling .
7. Install the air outlet duct. Refer to Air Cleaner Outlet Duct Replacement in Engine Controls.
8. Inspect all sealing surfaces for leaks after starting the engine. Refer to Cooling System Leak Testing .