Thermostat: Service and Repair

Engine Coolant Thermostat Replacement (LZE-3.5L Flex Fuel, LZ4-3.5L Gas, LZG-3.9L Flex Fuel)

Removal Procedure




1. Drain the cooling system. Refer to Cooling System Draining and Filling (9C1, 9C3 Static Fill) (Service and Repair)Cooling System Draining and Filling (LZE, LZ4, LGD Static Fill) (Service and Repair)Cooling System Draining and Filling (LZE, LZ4, LGD, 9C1, 9C3, GE47716 Fill) (Service and Repair).
2. Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement (Service and Repair) or Air Cleaner Outlet Duct Replacement (Service and Repair).
3. Reposition the radiator outlet hose clamp at the thermostat housing.
4. Remove the radiator outlet hose from the thermostat housing (3.5L shown, 3.9L similar).




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 (3.5L shown, 3.9L similar).
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 (Service and Repair) or Air Cleaner Outlet Duct Replacement (Service and Repair).
7. Fill the cooling system. Refer to Cooling System Draining and Filling (9C1, 9C3 Static Fill) (Service and Repair)Cooling System Draining and Filling (LZE, LZ4, LGD Static Fill) (Service and Repair)Cooling System Draining and Filling (LZE, LZ4, LGD, 9C1, 9C3, GE47716 Fill) (Service and Repair).
8. Inspect the system for leaks.