Engine Block Heater: Service and Repair

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

Removal Procedure
1. Drain the cooling system/engine block.
2. Raise and suitably support the vehicle.





3. Remove the oil pan skid plate bolts and plate.





4. Remove the oil cooler hose bracket bolt.
5. Remove the oil cooler hose adapter bolts.
6. Remove and discard the oil cooler hose adapter gasket.
7. Position the oil cooler hose adapter end out of the way.





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





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

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

Installation Procedure
1. If reusing 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.).





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





4. Position the oil cooler hose adapter end.
5. Install a NEW oil cooler hose adapter gasket.
6. Install the oil cooler hose adapter bolts.
Tighten the bolts to 12 Nm (106 inch lbs.).
7. Install the oil cooler hose bracket bolt.
Tighten the bolt to 25 Nm (18 ft. lbs.).





8. Install the oil pan skid plate and bolts.
Tighten the bolts to 20 Nm (15 ft. lbs.).
9. Lower the vehicle.
10. Fill the cooling system/engine block.