Removal Procedure

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Disconnecting/Connecting Coolant Heater Electrical Connector

Courtesy of GENERAL MOTORS CORP.

Drain the cooling system. Refer to Draining and Filling Cooling System (LL8) or Draining and Filling Cooling System (LM4) .
Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
Disconnect the coolant heater (1) electrical connector.

Fig 2: Removing/Installing Coolant Heater From Engine Block

Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Do not score the surface of the engine block hole when removing the coolant heater.

Remove the coolant heater from the engine block.
Remove any burrs, sealer, paint or other rough spots.