GM Service Manual Online
For 1990-2009 cars only

Engine Coolant Thermostat Replacement LAT

Removal Procedure


    Object Number: 1812217  Size: SH
  1. Drain the cooling system. Refer to Cooling System Draining and Filling.
  2. Reposition the radiator outlet hose clamp at the thermostat cover.
  3. Remove the radiator outlet hose from the thermostat cover.
  4. Remove the battery tray. Refer to Battery Tray Replacement.

  5. Object Number: 1713064  Size: SH
  6. Remove the thermostat cover bolts and cover.
  7. Remove the thermostat.
  8. Remove and discard the thermostat cover O-ring seal.

Installation Procedure


    Object Number: 1713064  Size: SH
  1. Install a NEW thermostat cover O-ring seal.
  2. Install the thermostat.
  3. Caution: Refer to Fastener Caution in the Preface section.

  4. Install the thermostat cover bolts and tighten to 10 N·m (89 lb in).

  5. Object Number: 1812217  Size: SH
  6. Install the battery tray. Refer to Battery Tray Replacement.
  7. Install the radiator outlet hose to the thermostat cover.
  8. Position the radiator outlet hose clamp at the thermostat cover.
  9. Fill the cooling system. Refer to Cooling System Draining and Filling.

Engine Coolant Thermostat Replacement LZ4

Removal Procedure


    Object Number: 1876468  Size: SH
  1. Remove the radiator outlet hose. Refer to Radiator Outlet Hose Replacement.
  2. Remove wire harness clamp from thermostat housing stud (1).

  3. Object Number: 1876480  Size: SH
  4. Remove the thermostat housing bolt (1) and nut (2).
  5. Remove the thermostat housing (3).
  6. Remove the thermostat.

Installation Procedure

    Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 1876480  Size: SH
  1. Install the thermostat with housing (3).
  2. 1.1. Install a new gasket.
    1.2. Position the thermostat with the housing.
    1.3. Apply thread sealant PST 565® to the bolt threads.
    1.4. Install the housing bolt (2) and nut (1) and tighten to 10 N·m (89 lb in).

    Object Number: 1876468  Size: SH
  3. Install the wire harness clamp to the thermostat housing stud (1).
  4. Install the radiator outlet hose. Refer to Radiator Outlet Hose Replacement.

Engine Coolant Thermostat Replacement LY7

Removal Procedure


    Object Number: 1846153  Size: SH
  1. Partially drain the cooling system. Refer to Cooling System Draining and Filling.
  2. Remove the radiator outlet hose from the thermostat housing.
  3. Remove the heater inlet and outlet hoses.
  4. Remove the surge tank outlet hose.
  5. Remove the thermostat housing bolts (1).
  6. Remove the housing.
  7. Remove the thermostat (2) and discard the thermostat gasket.

Installation Procedure


    Object Number: 1846153  Size: SH
  1. Install the thermostat  (2) with a NEW thermostat gasket.
  2. Caution: Refer to Fastener Caution in the Preface section.

  3. Install the thermostat housing bolts (1) and tighten to 10 N·m (89 lb in).
  4. Install the surge tank outlet hose.
  5. Install the heater inlet and outlet hoses.
  6. Install the radiator outlet hose to the thermostat housing.
  7. Fill the cooling system. Refer to Cooling System Draining and Filling.