GM Service Manual Online
For 1990-2009 cars only

Engine Coolant Thermostat Replacement RPO LX9

Removal Procedure


    Object Number: 1641124  Size: SH
  1. Remove the thermostat housing. Refer to Engine Coolant Thermostat Housing Replacement .
  2. Remove the thermostat.
  3. Remove and discard the thermostat O-ring seal.
  4. Clean and inspect the thermostat housing sealing surfaces.

Installation Procedure


    Object Number: 1641124  Size: SH
  1. Install a NEW thermostat O-ring seal.
  2. Install the thermostat.
  3. Install the thermostat housing. Refer to Engine Coolant Thermostat Housing Replacement .

Engine Coolant Thermostat Replacement RPO LY7

Removal Procedure

Important: The thermostat and thermostat housing are serviced as a assembly.


    Object Number: 1412152  Size: SH
  1. Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement .
  2. Remove the throttle body assembly. Refer to Throttle Body Assembly Replacement .
  3. Remove the heater pipes. Refer to Heater Pipes Replacement .
  4. Remove the coolant outlet pipe. Refer to Engine Coolant Outlet Pipe Replacement .
  5. Important: Use a universal or swivel socket with a long extension in order to remove the bolts.

  6. Remove the thermostat housing bolts.
  7. Remove the thermostat housing.

  8. Object Number: 1412155  Size: SH
  9. Remove and discard the thermostat housing gasket.
  10. Clean the thermostat housing and heater pipe sealing surfaces.

Installation Procedure


    Object Number: 1412155  Size: SH
  1. Position a NEW thermostat housing gasket to the thermostat housing.

  2. Object Number: 1412152  Size: SH
  3. Position the thermostat housing to the engine.
  4. Notice: Refer to Fastener Notice in the Preface section.

  5. Install the thermostat housing bolts.
  6. Tighten
    Tighten the bolts to 10 N·m (89 lb in).

  7. Install the coolant outlet pipe. Refer to Engine Coolant Outlet Pipe Replacement .
  8. Install the heater pipes. Refer to Heater Pipes Replacement .
  9. Install the throttle body assembly. Refer to Throttle Body Assembly Replacement .
  10. Install the air cleaner assembly. Refer to Air Cleaner Assembly Replacement .
  11. Fill the cooling system. Refer to Cooling System Draining and Filling .