Thermostat: Service and Repair

Thermostat Replacement (LY7)

Removal Procedure

1. Partially drain the cooling system.

Important: Do NOT separate the upper and lower intake manifolds.

2. Remove the upper intake manifold with the lower intake manifold.
3. Disconnect the surge tank hose from the thermostat.




4. Remove the coolant pipe/thermostat housing bolt (1).
5. Remove the coolant pipe bolt (3).
6. Remove the coolant inlet pipe from the thermostat housing.
7. Remove and discard the coolant pipe O-ring seal (2).




8. Remove the thermostat bolts.
9. Remove the thermostat and discard the thermostat seal.

Installation Procedure




1. Install the thermostat with a NEW thermostat seal.

Notice: Refer to Fastener Notice in Service Precautions.

2. Install the thermostat bolts.

Tighten the thermostat bolts to 10 N.m (89 lb in).




3. Install the coolant pipe, NEW seal (2), and fasteners (1 and 3).
4. Install the surge tank hose to the thermostat.
5. Install the upper intake manifold with the lower intake manifold.
6. Fill the cooling system.