Removal Procedure
- Drain the engine coolant. Refer to 
Cooling System Draining and Filling
 .
 
- Disconnect the coolant heater cord (1) from the heater.
 
Important: Do not score the surface of the engine block hole when removing the coolant heater.
- Remove the coolant heater.
 
Installation Procedure
- Remove any burrs, sealer, paint or other foreign material from the threads/sealing surface of the engine block
and from the old coolant heater if the heater is to be reused.
 
- 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 Component Fastener Tightening Notice in the Preface section.
- Install the coolant heater to the engine block.
 
Tighten
Tighten the coolant heater to 50 N·m (37 lb ft).
- Connect the coolant heater cord (1) to the heater.
 
- Fill the cooling system. Refer to 
Cooling System Draining and Filling
.