Removal Procedure

WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

Drain the cooling system. Refer to DRAINING AND FILLING COOLING SYSTEM (BODY VIN CODE 6) or DRAINING AND FILLING COOLING SYSTEM (BODY VIN CODE 3) .
Raise and suitably support the vehicle. Refer to LIFTING AND JACKING THE VEHICLE in General Information.
Disconnect the coolant heater (1) electrical connector.

Fig 1: Disconnecting Coolant Heater Electrical Connector (5.3L Engine)
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.

Fig 2: Removing Coolant Heater From Engine Block (5.3L Engine)
Courtesy of GENERAL MOTORS CORP.