Thermostat: Service and Repair

Thermostat Replacement

Removal Procedure

1. Remove the fuel injector sight shield.
2. Drain the coolant until the coolant level is below the thermostat.
3. Remove the crossover exhaust pipe.
4. Remove the radiator hose from the thermostat housing.




5. Remove the thermostat housing bolts (2) and clean any sealer from the bolt threads.
6. Remove the thermostat housing (1).
7. Remove the thermostat (3).
8. Clean the mating surfaces.

Installation Procedure




1. Install the thermostat (3).
2. Install the thermostat housing (1).
3. Install RTV sealer, GM P/N 12378478 (Canadian P/N 88900041) or the equivalent, to the thermostat housing bolt threads.

Notice: Refer to Fastener Notice .

4. Install the thermostat housing bolts (2).

Tighten the bolts to 25 N.m (18 lb ft).

5. Install the radiator hose to the thermostat housing.
6. Install the crossover exhaust pipe.
7. Install the fuel injector sight shield.
8. Fill the cooling system.
9. Inspect the cooling system for leaks. Repair as necessary.