GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 38185 Hose Clamp Pliers

Removal Procedure


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

  6. Object Number: 466875  Size: SH
  7. Disconnect the heater outlet hose from the thermostat bypass pipe (2).
  8. Disconnect the throttle body inlet and outlet hoses from the thermostat bypass pipe (1).

  9. Object Number: 54419  Size: SH
  10. Remove the thermostat bypass pipe-to-throttle body nut.

  11. Object Number: 187083  Size: SH
  12. Using the J 38185 , 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-to-engine front cover 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-to-engine front cover bolt.
  4. Tighten
    Tighten the thermostat bypass pipe-to-front cover bolt to 11 N·m (98 lb in).


    Object Number: 187083  Size: SH
  5. Connect the thermostat bypass pipe hose.
  6. Using the J 38185 , reposition and secure the hose clamp at the thermostat bypass pipe.

  7. Object Number: 54419  Size: SH
  8. Install the thermostat bypass pipe to the throttle body stud.
  9. Install the thermostat bypass pipe-to-throttle body nut.
  10. Tighten
    Tighten the thermostat bypass pipe-to-throttle body nut to 25 N·m (18 lb ft).


    Object Number: 466875  Size: SH
  11. Connect the heater outlet hose to the thermostat bypass pipe (2).
  12. Connect the throttle body inlet and outlet hoses to the thermostat bypass pipe (1).

  13. Object Number: 70064  Size: SH
  14. Connect the inlet hose at the thermostat housing.
  15. Using the J 38185 , reposition and install the inlet hose clamp at the thermostat housing.
  16. Install the spark plug wires at the left bank. Refer to Spark Plug Wire Replacement in Engine Controls - 3.1L.
  17. Install the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls - 3.1L.
  18. Fill the cooling system. Refer to Cooling System Draining and Filling .
  19. Inspect for leaks.