Coolant Heater

Coolant Heater Replacement (4.8L, 5.3L, and 6.0L Engines)

Removal Procedure
1. Drain the cooling system.
2. Raise and suitably support the vehicle. Refer to Vehicle Lifting.





3. Disconnect the coolant heater electrical connector (2).





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

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

Installation Procedure
1. If re-using the old coolant heater, apply thread sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent to the threads.





Notice: Refer to Fastener Notice in Service Precautions.

2. Install the coolant heater to the engine block.
- Tighten the coolant heater to 50 Nm (37 ft. lbs.).





Notice: The heater cord must not touch the engine, hot pipes, manifold, or any moving parts. Route the cord to the left front of the engine compartment securing with tie straps as necessary to prevent damage.

3. Connect the coolant heater electrical connector (2).
4. Lower the vehicle.
5. Fill the cooling system.