Coolant Heater Replacement

Coolant Heater Replacement (With LC9, L76,or L92)

Removal Procedure

1. Drain the cooling system/engine block. Refer to Cooling System Draining and Filling (Static Fill) (Service and Repair).
2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle (Service and Repair).
3. Remove the oil pan skid plate bolts and plate, if equipped.

4. For vehicles with regular production option (RPO) L76 (6.0L), perform the following steps. Otherwise, proceed to step 9.
5. Remove the oil cooler hose bracket bolt (1), if equipped.
6. Remove the oil cooler hose adapter bolts (2), if equipped.
7. Remove and discard the oil cooler hose adapter gasket, if equipped.
8. Position the oil cooler hose adapter end out of the way, if equipped.

9. Disconnect the coolant heater cord electrical connector.

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

10. Remove the coolant heater from the engine block.
11. 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.

Caution: Refer to Fastener Caution (Fastener Caution).

2. Install the coolant heater to the engine block and tighten to 50 Nm(37 lb ft).

3. Connect the coolant heater cord electrical connector.

4. For vehicles with RPO L76 (6.0L) perform the following steps otherwise proceed to step 9.
5. Position the oil cooler hose adapter end, if equipped.
6. Install a NEW oil cooler hose adapter gasket, if equipped.
7. If equipped, install the oil cooler hose adapter bolts (2) And tighten to 12 Nm(106 lb in).
8. If equipped, install the oil cooler hose bracket bolt (1) and tighten to 25 Nm(18 lb ft).

9. If equipped, position and install the oil pan skid plate and bolts and tighten to 20 Nm(15 lb ft)
10. Lower the vehicle.
11. Fill the cooling system/engine block. Refer to Cooling System Draining and Filling (Static Fill) (Service and Repair).