GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2009 🢒 G8 🢒 Engine 🢒 Engine Cooling 🢒 Engine Coolant Thermostat Housing Replacement

Removal Procedure

    Warning: Refer to Battery Disconnect Warning in the Preface section.

    Note: Refer to Battery Negative Cable Disconnection and Connection.

  1. Disconnect the battery ground cable from the battery.

    2. Warning: Refer to Radiator Cap Removal Warning in the Preface section.

  2. Ensure engine is below 50°C before removing the coolant pressure cap.
  3. Remove the radiator air baffle and deflector. Refer to Radiator Air Upper Baffle and Deflector Replacement.
  4. Remove the air intake duct. Refer to Air Cleaner Inlet Duct Replacement.

    5. Warning: Refer to Safety Glasses Warning in the Preface section.

    Danger: To avoid any vehicle damage, serious personal injury or death when major components are removed from the vehicle and the vehicle is supported by a hoist, support the vehicle with jack stands at the opposite end from which the components are being removed and strap the vehicle to the hoist.

  5. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  6. Drain the coolant into a suitable container. Refer to Cooling System Draining and Filling.
  7. Lower the vehicle.

    8. Warning: Refer to Safety Glasses Warning in the Preface section.


    Object Number: 1949738 Size: SH
  8. Release the retaining hose clamp (2) and detach the hose (3) from the thermostat housing end (1).

    9. Object Number: 1949739 Size: SH
  9. Remove the thermostat housing (2) to water pump retaining bolts (1), and remove thermostat housing.
  10. If the housing is to be replaced, discard the O-ring.

Installation Procedure
  1. Install thermostat. Refer to Engine Coolant Thermostat Replacement.
  2. Ensure all mating surfaces are thoroughly cleaned, using only a fine abrasive material.

    3. Object Number: 1949739 Size: SH

    Note: Ensure a new O-ring seal is used.

  3. Install the thermostat housing (2).

    4. Caution: Refer to Fastener Caution in the Preface section.

  4. Install the thermostat housing to water pump retaining bolts (1) and tighten to 14 N·m (124 lb in).

    5. Warning: Refer to Safety Glasses Warning in the Preface section.

    Caution: Refer to Installing Hoses without Twists or Bends Caution in the Preface section.


    Object Number: 1949738 Size: SH
  5. Install the hose (3) to the thermostat housing (1) by opening the retaining hose clamp (2) and securing it over the hose.
  6. Install the radiator air baffle and deflector. Refer to Radiator Air Upper Baffle and Deflector Replacement.
  7. Install the air intake duct. Refer to Air Cleaner Inlet Duct Replacement.
  8. Fill the cooling system. Refer to Cooling System Draining and Filling.
  9. Connect the battery ground cable to the battery. Refer to Battery Negative Cable Disconnection and Connection.
  10. Inspect cooling system for leaks.