GM Service Manual Online
For 1990-2009 cars only

Coolant Heater Replacement LE5

Removal Procedure


    Object Number: 1578338  Size: SH
  1. Disconnect the coolant heater cord.

  2. Object Number: 1578336  Size: SH
  3. Remove the coolant heater bolt.
  4. Remove the coolant heater.

Installation Procedure


    Object Number: 1578336  Size: SH
  1. Install the coolant heater.
  2. Notice: Refer to Fastener Notice in the Preface section.

  3. Install the coolant heater bolt.
  4. Tighten
    Tighten the bolt to 10 N·m (89 lb in).


    Object Number: 1578338  Size: SH
  5. Connect the coolant heater cord.

Coolant Heater Replacement LZ4 and LZ9

Removal Procedure


    Object Number: 1584090  Size: SH
  1. Drain the cooling system. Refer to Cooling System Draining and Filling .
  2. Disconnect the engine coolant heater cord from the engine coolant heater.

  3. Object Number: 1584087  Size: SH
  4. Remove the engine coolant heater.
  5. Clean the engine coolant heater opening.

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1584087  Size: SH
  1. Apply sealer GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the threads of the engine coolant heater, if necessary.
  2. Install the engine coolant heater.
  3. Tighten
    Tighten the coolant heater to 60 N·m (44 lb ft).


    Object Number: 1584090  Size: SH
  4. Connect the engine coolant heater cord to the engine coolant heater.
  5. Lower the vehicle.
  6. Fill the cooling system. Refer to Cooling System Draining and Filling .
  7. Inspect for leaks.

Coolant Heater Replacement LY7

Removal Procedure

  1. Turn the ignition OFF.
  2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  3. Remove the rear transmission Mount. Refer to Transmission Rear Mount Replacement
  4. Disconnect the coolant heater cord from the coolant heater.

  5. Object Number: 1837206  Size: SH
  6. Remove the coolant heater.

Installation Procedure


    Object Number: 1837206  Size: SH
  1. Install the coolant heater.
  2. Connect the coolant heater cord to the coolant heater.
  3. Install the rear transmission Mount. Refer to Transmission Rear Mount Replacement
  4. Lower the vehicle.