GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2003 🢒 Montana Ext. 🢒 Engine 🢒 Engine Cooling 🢒 Coolant Heater Replacement

Removal Procedure
  1. Turn the ignition OFF.
  2. Drain the engine cooling system. Refer to Cooling System Draining and Filling .
  3. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  4. Remove the right front wheel. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
  5. Remove the right engine splash shield. Refer to Engine Splash Shield Replacement in Body Front End.

    6. Object Number: 476150 Size: SH
  6. Remove the engine coolant heater cord from the engine coolant heater.
  7. Loosen the coolant heater bolt/screw.

    8. Object Number: 476152 Size: SH
  8. Remove the coolant heater.

Installation Procedure
  1. Apply GM P/N 9985164, or equivalent, to the coolant heater seal.

    2. Object Number: 296172 Size: SH
  2. Ensure that the coolant heater element is horizontal and pointed toward the front of the engine.

    3. The 3 o'clock position (2) is DESIRED.

    The 2 o'clock position (1) and the 4 o'clock position (3) are acceptable.


    Object Number: 476152 Size: SH
  3. Install the coolant heater.

    4. 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.

  4. Install the coolant heater bolt/screw.

    5. Tighten
    Tighten the coolant heater bolt/screw to 2 N·m (18 lb in).


    Object Number: 476150 Size: SH
  5. Install the engine coolant heater cord to the engine coolant heater.
  6. Install the right engine splash shield. Refer to Engine Splash Shield Replacement in Body Front End.
  7. Install the right front wheel. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
  8. Lower the vehicle.
  9. Fill the engine cooling system. Refer to Cooling System Draining and Filling .