For 1990-2009 cars

### Removal Procedure

1. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
2. Remove the following components from the cylinder block:

• | The 2 nuts (1)

• | The thermostat housing

3. Remove the following components from the thermostat housing:

• | The thermostat

• | The O-ring

4. Clean the following materials from the thermostat cap:

• | Corrosion

• | Debris

5. Clean the cylinder block mating surfaces.
6. Inspect the thermostat. Refer to Thermostat Diagnosis in Engine Cooling.

### Installation Procedure

Important: Position the air bleed valve facing upward.

1. Install the thermostat.
2. Install a new thermostat O-ring.
3. Install the thermostat housing to the cylinder block.

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. Use the 2 nuts (1) in order to secure the thermostat cap.

Tighten
Tighten the thermostat cap nuts to 9 N·m (80 lb in).

5. Fill the radiator using approved coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
6. Start the engine.
7. Run the engine until the coolant is at operating temperature. The coolant is at operating temperature when the following conditions exist:

• | The hoses feel warm.

• | The coolant is flowing through the radiator.

8. Inspect for leaks in the cooling system.
9. Turn off the engine.
10. Install the radiator cap.