GM Service Manual Online
For 1990-2009 cars only

Engine Coolant Thermostat Housing Replacement Gas Engine

Removal Procedure

  1. Remove the front wheelhouse panel.

  2. Object Number: 198949  Size: SH
  3. Remove the front intake air duct (1) from the air filter housing.
  4. Drain the coolant. Refer to Cooling System Draining and Filling .
  5. Remove the upper radiator hose from the coolant outlet.
  6. Remove the coolant outlet bolts.

  7. Object Number: 439195  Size: SH
  8. Remove the coolant outlet.
  9. Remove the coolant outlet gasket.
  10. Remove the thermostat housing (1).
  11. Clean the following components:
  12. • The surface of the intake manifold
    • The coolant outlet
  13. Inspect the manifold and the coolant outlet mating surfaces for the following conditions:
  14. • Pits
    • Cracks
    • Other damage that could cause leaking

Installation Procedure


    Object Number: 439195  Size: SH
  1. Install thermostat housing (1).
  2. Install the coolant outlet gasket.
  3. Install the coolant outlet.
  4. 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.

  5. Install the coolant outlet bolts.
  6. Tighten
    Tighten the coolant outlet bolts to 37 N·m (27 lb ft).

  7. Install the upper radiator hose to the coolant outlet.

  8. Object Number: 198949  Size: SH
  9. Install the front intake air duct (1) to the air filter housing.
  10. Install the front wheelhouse panel.
  11. Fill the cooling system. Refer to Cooling System Draining and Filling .
  12. Inspect the system for leaks.

Engine Coolant Thermostat Housing Replacement L21/LP4

Removal Procedure

  1. Remove the front left wheelhouse panel.

  2. Object Number: 198949  Size: SH
  3. Remove the front intake air duct (1) from the air filter housing.
  4. Drain the coolant. Refer to Cooling System Draining and Filling .
  5. Remove the upper radiator hose from the coolant outlet.
  6. Remove the coolant outlet bolts.

  7. Object Number: 72728  Size: SH
  8. Remove the coolant outlet.
  9. Remove the coolant outlet gasket.
  10. Clean the following components:
  11. • The surface of the intake manifold
    • The coolant outlet
  12. Inspect the intake manifold and the coolant outlet mating surfaces for the following conditions:
  13. • Pits
    • Cracks
    • Other damage that could cause leaks

Installation Procedure

  1. Install the coolant outlet gasket.
  2. Install the thermostat.

  3. Object Number: 72728  Size: SH
  4. Install the coolant outlet.
  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. Install the coolant outlet bolts.
  7. Tighten
    Tighten the coolant outlet bolts to 42 N·m (31 lb ft).

  8. Install the upper radiator hose to the coolant outlet.

  9. Object Number: 198949  Size: SH
  10. Install the front intake air duct (1) to the air filter housing.
  11. Install the front left wheelhouse panel.
  12. Fill the cooling system. Refer to Cooling System Draining and Filling .
  13. Inspect the system for leaks.