INSPECTION
Replace the thermostat if the valve does not close completely at an ambient temperature or if the following test shows unsatisfactory results.
Immerse the thermostat and a thermometer in water. Raise water temperature gradually, and measure the temperature and valve lift when the valve begins to open and when the valve is fully opened. During the test, agitate the water for even temperature distribution. The measurement should be to the specification.
- Starts to open: 76-80°C (169-176°F)
- Fully opens: 91°C (196°F)
Scheme 88
Scheme 89
Scheme 90
Scheme 91
Scheme 92
Scheme 93
Scheme 94
Scheme 95
Scheme 96
Scheme 97
Scheme 98
- Disconnect the battery ground cable.
- Lift-up the vehicle.
- Drain engine coolant completely. See «DRAINING OF ENGINE COOLANT»(/subaru/impreza-wrx/gdgg-2002-2005/remont/cooling-fan/#engine-cooling-system) , Replacement, Engine Coolant.
- Disconnect the connectors of radiator main fan (A) and sub fan (B) motor.
- Disconnect the radiator outlet hose (A) from thermostat cover.
- Disconnect the ATF cooler hoses (B) from the radiator. (AT vehicles only)
- Lower the vehicle.
- Disconnect the over flow hose.
- Remove the reservoir tank.
- Disconnect the radiator inlet hose from the engine.
- Remove the radiator upper brackets.
- Detach the power steering hose from the clip on the radiator.
- While slightly lifting radiator, slide it to left.
- Lift the radiator up and away from the vehicle.