GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 Engine 🢒 Engine Cooling 🢒 Engine Coolant Thermostat Replacement

Removal Procedure

Important: The water pump inlet and thermostat MUST be replaced as an assembly. The thermostat is not serviceable separately.

  1. Drain the cooling system. Refer to Cooling System Draining and Filling .
  2. Reposition the outlet hose clamp at the water pump inlet.
  3. Remove the outlet hose from the water pump inlet.

    4. Object Number: 370076 Size: SH
  4. Remove the water pump inlet bolts.
  5. Remove the water pump inlet.

    6. Object Number: 370073 Size: SH

    Important: The O-ring seal is integral to the thermostat housing.

  6. Remove the thermostat housing.

Installation Procedure

    Object Number: 370073 Size: SH

    Important: Ensure that the new thermostat housing has an O-ring seal and is in the groove correctly.

  1. Install a new thermostat housing.

    2. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 370076 Size: SH
  2. Install the water pump inlet with thermostat.
  3. Install the water pump inlet bolts.

    4. Tighten
    Tighten the water pump inlet bolts to 14 N·m (10 lb ft).

  4. Install the outlet hose to the water pump inlet.
  5. Position the outlet hose clamp at the water outlet.
  6. Fill the cooling system. Refer to Cooling System Draining and Filling .