GM Service Manual Online
For 1990-2009 cars only

Engine Coolant Thermostat Replacement 2.0L Engine

Removal Procedure

Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.

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

  2. Object Number: 467823  Size: SH
  3. Remove the three bolts (1) and position the A/C compressor aside.

  4. Object Number: 488773  Size: SH
  5. Remove the radiator hose clamp (1) from the thermostat housing.
  6. Remove the radiator hose from the thermostat housing.

  7. Object Number: 466462  Size: SH
  8. Remove the three bolts and the thermostat housing (3).
  9. Remove the thermostat and the O-ring from the thermostat housing.
  10. Clean any corrosion or debris from the thermostat housing.
  11. Clean the mating surfaces.
  12. Inspect the thermostat. Refer to Thermostat Diagnosis .

Installation Procedure

    Important: Position the air bleed valve so that it aligns with the mark on the cylinder head.

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

  3. Object Number: 466462  Size: SH
  4. Install the thermostat housing (3).
  5. 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.

  6. Secure the thermostat housing (3) with three bolts.
  7. Tighten
    Tighten the thermostat housing bolts to 16 N·m (12 lb ft).


    Object Number: 467823  Size: SH
  8. Install the A/C compressor and secure with three bolts (1).
  9. Tighten
    Tighten the A/C compressor bolts to 23 N·m (17 lb ft).


    Object Number: 488773  Size: SH
  10. Install the radiator hose and clamp (1) to the thermostat housing.
  11. Fill the radiator with approved coolant. Refer to Cooling System Draining and Filling .
  12. Start the engine.
  13. Allow the coolant to attain operating temperature (both hoses feel warm and the coolant is flowing through the radiator).
  14. Check for leaks in the cooling system.
  15. Shut off the engine.
  16. Install the radiator cap.

Engine Coolant Thermostat Replacement 2.5L Engine

Removal Procedure

Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.

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

  2. Object Number: 722150  Size: SH
  3. Remove the lower radiator pipe bolt (1).

  4. Object Number: 722157  Size: SH
  5. Remove the thermostat cap bolts (1), cap (2) and the thermostat.

Installation Procedure

    Important: Align the thermostat air bleed valve (1) to the recession on the thermostat case (2).


    Object Number: 722174  Size: SH
  1. Position the new thermostat and O-ring on the thermostat case.
  2. 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.


    Object Number: 722157  Size: SH
  3. Secure the thermostat housing cap (2) with two bolts (1).
  4. Tighten
    Tighten the thermostat housing bolts to 16 N·m (12 lb ft).


    Object Number: 722150  Size: SH
  5. Install the lower radiator pipe bolt.
  6. Fill the radiator with an approved coolant. Refer to Cooling System Draining and Filling .