Thermostat: Service and Repair

Engine Coolant Thermostat Replacement (LZ4 and LZ9) (3.5L)

Removal Procedure




1. Drain the cooling system. Refer to Cooling System Draining and Filling (GE 47716 Fill) Cooling System Draining and Filling (GE 47716 Fill)Cooling System Draining and Filling (LY7, LZE, LZ4, LZ9) Cooling System Draining and Filling (GE 47716 Fill).
2. Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement Air Cleaner Outlet Duct Replacement
3. Reposition the radiator outlet hose clamp at the thermostat housing.
4. Remove the radiator outlet hose from the thermostat housing.




5. Remove the thermostat housing bolt/stud.
6. Remove the thermostat housing and gasket.
7. Remove the thermostat.
8. Clean the gasket surfaces.

Installation Procedure




1. Install a NEW thermostat.
2. Position a NEW gasket and the thermostat housing to the engine block.

Caution: Refer to Fastener Caution Fastener Caution.

3. Install the thermostat housing bolt/stud.

Tighten the bolt/stud to 10 Nm (89 lb in).




4. Install the radiator outlet hose to the thermostat housing.
5. Position the radiator outlet hose clamp at the thermostat housing.
6. Install the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement Air Cleaner Outlet Duct Replacement
7. Fill the cooling system. Refer to Cooling System Draining and Filling (GE 47716 Fill) Cooling System Draining and Filling (GE 47716 Fill)Cooling System Draining and Filling (LY7, LZE, LZ4, LZ9) Cooling System Draining and Filling (GE 47716 Fill).
8. Inspect the system for leaks.