Thermostat: Service and Repair

1. Disconnect battery ground.
2. Drain cooling system down to thermostat level or below, then remove thermostat housing.
3. Remove thermostat.
4. Reverse procedure to install, noting the following:
a. Immerse thermostat in hot coolant to check proper value opening temperature. Replace if necessary.
b. Ensure flange of thermostat is correctly seated in socket of thermostat housing. If thermostat is installed in wrong direction, bottom of thermostat will touch rib inside intake manifold, making it impossible for thermostat to operate properly.
c. Install a new gasket and coolant outlet fitting.
d. Refill system with clean coolant.