Coolant Heater Replacement (5.3L (W/RPO L33)

Coolant Heater Replacement (5.3L (w/RPO L33))

Removal Procedure
1. Remove the engine protection shield.
2. Remove the front drive axle shield.
3. Drain the cooling system. Refer to Draining and Filling Cooling System (Static Fill) Draining and Filling Cooling System (w/RPO HP2) Draining and Filling Cooling System (Vac-N-Fill).
4. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.





5. Disconnect the coolant heater electrical connector.

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

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

Installation Procedure
1. If reusing the old coolant heater, apply thread sealant to the to the threads. Refer to Sealers, Adhesives, and Lubricants for the correct part number.

2. Notice: Refer to Fastener Notice in Service Precautions.

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





3. 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.

Connect the coolant heater electrical connector.
4. Lower the vehicle.
5. Fill the cooling system. Refer to Draining and Filling Cooling System (Static Fill) Draining and Filling Cooling System (w/RPO HP2) Draining and Filling Cooling System (Vac-N-Fill).
6. Install the front drive axle shield.
7. Install the engine protection shield.