GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2004 🢒 Monte Carlo 🢒 Engine 🢒 Engine Cooling 🢒 Heater Core Replacement

Tools Required

J 38185 Hose Clamp Pliers

Removal Procedure
  1. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical-3.8L.
  2. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

    3. Object Number: 1204093 Size: SH
  3. UseJ 38185 in order to position aside the heater hose inlet and outlet clamps at the heater core.
  4. Disconnect the inlet and outlet heater hose from the heater core.
  5. Remove the RH Instrument Panel Closeout/Insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Right Side in Instrument Panel, Gages, and Console.
  6. Remove the LH Instrument Panel Closeout/Insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages, and Console.
  7. Remove the floor carpet. Refer to Front Floor Panel Carpet Replacement in Interior Trim.
  8. Remove the rear floor air outlet duct from the holes in the floor reinforcement.
  9. Disconnect the rear floor air outlet duct from the heater air outlet cover.
  10. Remove the rear floor air outlet duct.

    11. Object Number: 1197427 Size: SH
  11. Remove the heater air outlet cover screws (2).
  12. Remove the heater air outlet cover heat stakes (1) with a small chisel.
  13. Remove the heater air outlet cover from the HVAC module assembly.

    14. Object Number: 1197437 Size: SH
  14. Remove the heater core cover screws (2).
  15. Remove the heater core cover heat stakes (1) with a small chisel.
  16. Remove the heater core cover from the HVAC module assembly.

    17. Object Number: 1197439 Size: SH
  17. Remove the heater core from the HVAC module assembly.

    18. Object Number: 1197441 Size: SH
  18. Remove the heater core foam seal (1) from the HVAC module assembly.

Installation Procedure

    Object Number: 1197441 Size: SH
  1. Install a new heater core foam seal (1) to the HVAC module assembly.

    2. Object Number: 1197439 Size: SH
  2. Install the heater core to the HVAC module assembly.
  3. From the inside of the heater core cover, drill the dimples adjacent to the heat stakes using a 5.5 mm (7/32 in) drill bit.

    4. Object Number: 1197437 Size: SH
  4. Install the heater core cover to the HVAC module assembly.

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

  5. Install the heater core cover screws (2).

    6. Tighten
    Tighten all screws to 1.5 N·m (13 lb in).

  6. From the inside of the heater air outlet cover, drill the dimples adjacent to the heat stakes using a 5.5 mm (7/32 in) drill bit.

    7. Object Number: 1197427 Size: SH
  7. Install the heater air outlet cover.
  8. Install the heater air outlet cover screws (2).

    9. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).

  9. Connect the rear floor air outlet duct to the heater air outlet cover.
  10. Install the rear floor air outlet duct to the holes in the floor reinforcement.
  11. Install the floor carpet. Refer to Front Floor Panel Carpet Replacement in Interior Trim.
  12. Install the RH Instrument Panel Closeout/Insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Right Side in Instrument Panel, Gages, and Console.
  13. Install the LH Instrument Panel Closeout/Insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side in Instrument Panel, Gages, and Console.

    14. Object Number: 1204093 Size: SH
  14. Connect the inlet and outlet heater hose to the heater core.
  15. UseJ 38185 in order to reposition the heater hose inlet and outlet clamps to the heater core.
  16. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical-3.8L.
  17. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.