GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Tools Required

J 38185 Hose Clamp Pliers


    Object Number: 70064  Size: SH
  1. Drain the engine coolant from the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Carefully remove the throttle body air inlet duct. Refer to Air Cleaner Assembly Replacement in Engine Controls - 3.1L.
  3. Remove the LH engine mount strut. Refer to Engine Mount Strut Replacement in Engine Mechanical - 3.1L.
  4. Disconnect the left bank spark plug wires. Refer to Spark Plug Wire Harness Replacement in Engine Electrical.
  5. Use the J 38185 in order to reposition the hose clamp at the thermostat housing. Disconnect the upper radiator hose from the housing. Refer to Cooling System Draining and Filling in Engine Cooling.

  6. Object Number: 622761  Size: SH
  7. Disconnect the heater outlet hose (2) from the thermostat bypass pipe.
  8. Disconnect the throttle body inlet (3) and outlet (4) hoses from the thermostat bypass pipe.

  9. Object Number: 54419  Size: SH
  10. Remove the thermostat bypass pipe nut.

  11. Object Number: 187083  Size: SH
  12. Use the J 38185 in order to reposition the hose clamp at the thermostat bypass pipe.
  13. Disconnect the thermostat bypass pipe hose.

  14. Object Number: 187084  Size: SH
  15. Remove the thermostat bypass pipe bolt.
  16. Remove the thermostat bypass pipe.

Installation Procedure


    Object Number: 187084  Size: SH
  1. Install the thermostat bypass pipe.
  2. 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.

  3. Install the thermostat bypass pipe bolt.
  4. Tighten
    Tighten the thermostat bypass pipe bolt to 11 N·m (98 lb in).


    Object Number: 187083  Size: SH
  5. Connect the thermostat bypass pipe hose.
  6. Use the J 38185 in order to reposition and secure the hose clamp at the thermostat bypass pipe.

  7. Object Number: 54419  Size: SH
  8. install the thermostat bypass pipe nut.
  9. Tighten
    Tighten the thermostat bypass pipe nut to 25 N·m (18 lb ft).


    Object Number: 622761  Size: SH
  10. Connect the heater outlet hose (2) to the thermostat bypass pipe.
  11. Connect the throttle body inlet (3) and outlet (4) hoses to the thermostat bypass pipe.

  12. Object Number: 70064  Size: SH
  13. Connect the inlet hose at the thermostat housing.
  14. Use the J 38185 in order to reposition and install the inlet hose clamp at the thermostat housing.
  15. Install the left bank spark plug wires. Refer to Spark Plug Wire Harness Replacement in Engine Electrical.
  16. Install the LH engine mount strut. Refer to Engine Mount Strut Replacement in Engine Mechanical - 3.1L.
  17. Carefully install the throttle body air inlet duct. Refer to Air Cleaner Assembly Replacement in Engine Controls - 3.1L.
  18. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  19. Inspect for leaks.