Engine Cooling System (2.5L): Diagnosis Subaru Outback BH

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.

1. Starts to open: 76.0 - 80.0°C (169 - 176°F)
2. Fully opens: 91°C (196°F)

Checking Thermostat. Scheme 50

Scheme 51

Scheme 52

Scheme 53

Scheme 54

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Scheme 63

1. Disconnect battery ground cable. (Scheme 51): Disconnecting Battery Ground Cable
2. Lift-up the vehicle.
3. Remove under cover. (Scheme 52): Removing Under Cover
4. Drain engine coolant completely. See «DRAINING OF ENGINE COOLANT»(ref-178723-S41389615812005063000000), REPLACEMENT, Engine Coolant. (Scheme 53): Draining Engine Coolant
5. Disconnect connectors of radiator main fan (A) and sub fan (B) motor. (Scheme 54): Disconnecting Connectors Of Radiator Main Fan & Sub Fan Motor
6. Disconnect radiator outlet hose from thermostat cover. (Scheme 55): Disconnecting Radiator Outlet Hose From Thermostat Cover
7. Disconnect ATF cooler hoses from radiator. (AT vehicles only) (Scheme 56): Disconnecting ATF Cooler Hoses From Radiator
8. Lower the vehicle.
9. Remove air intake duct. (Scheme 57): Removing Air Intake Duct
10. Disconnect over flow hose. (Scheme 58): Disconnecting Over Flow Hose
11. Remove reservoir tank. (Scheme 59): Removing Reservoir Tank
12. Disconnect radiator inlet hose from engine. (Scheme 60): Disconnecting Radiator Inlet Hose From Engine
13. Remove radiator upper brackets. (Scheme 61): Removing Radiator Upper Brackets
14. Detach power steering hose from the clip on the radiator. (Scheme 62): Detaching Power Steering Hose From Radiator Clip
15. While slightly lifting radiator, slide it to left.
16. Lift radiator up and away from vehicle. (Scheme 63): Removing Radiator

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Scheme 75

1. Attach radiator mounting cushions to holes on the vehicle. (Scheme 64): Attaching Radiator Mounting Cushions
2. Install radiator while fitting radiator pins to cushions. NOTE: Fit pins on lower side of radiator into cushions on body side. (Scheme 65): Installing Radiator
3. Install radiator brackets and tighten bolts. Tightening torque: 18 N.m (1.8 kgf-m, 13.0 ft-lb) (Scheme 66): Installing Radiator Brackets
4. Attach power steering hose to the radiator. (Scheme 67): Attaching Power Steering Hose To Radiator Clip
5. Connect radiator inlet hose. (Scheme 68): Connecting Radiator Inlet Hose
6. Install reservoir tank. Tightening torque: 4.9 N.m (0.50 kgf-m, 3.6 ft-lb) (Scheme 69): Installing Reservoir Tank
7. Install air intake duct. (Scheme 70): Installing Air Intake Duct
8. Lift-up the vehicle.
9. Connect ATF cooler hoses. (AT vehicles only) (Scheme 71): Connecting ATF Cooler Hoses
10. Connect connectors to radiator main fan motor and sub fan motor. (Scheme 72): Connecting Main Fan & Sub Fan Connectors
11. Connect radiator outlet hose. (Scheme 73): Connecting Radiator Outlet Hose
12. Install under cover. (Scheme 74): Installing Under Cover
13. Lower the vehicle.
14. Connect battery ground cable. (Scheme 75): Connecting Battery Ground Cable
15. Fill coolant. See «FILLING OF ENGINE COOLANT»(ref-178723-S29728760692005063000000), REPLACEMENT, Engine Coolant.
16. Check ATF level. See «REPLACEMENT»(ref-175581-S40671530592005042200000), Automatic Transmission Fluid.

Scheme 76

1. Remove radiator cap, top off radiator, and attach tester to radiator in place of cap. (Scheme 76): Attaching Tester To Radiator
2. Apply a pressure of 157 kPa (1.6 kg/cm 2, 23 psi) to radiator to check if: Engine coolant leaks at/around radiator. Engine coolant leaks at/around hoses or connections. CAUTION: Engine should be off. Wipe engine coolant from check points in advance. Be careful to prevent engine coolant from spurting out when removing tester. Be careful also not to deform filler neck of radiator when installing or removing tester.

Scheme 77

1. Attach radiator cap to tester. (Scheme 77): Attaching Radiator Cap To Tester
2. Increase pressure until tester gauge pointer stops. Radiator cap is functioning properly if it holds the service limit pressure for five to six seconds. Standard pressure: 93 - 123 kPa (0.95 - 1.25 kg/cm 2, 14 - 18 psi) Service limit pressure: 83 kPa (0.85 kg/cm 2, 12 psi) CAUTION: Be sure to remove foreign matter and rust from the cap in advance otherwise, results of pressure test will be incorrect.

Scheme 78

1. Disconnect over flow hose from radiator filler neck position.
2. Remove bolts which install reservoir tank onto radiator main fan shroud.
3. Remove reservoir tank. (Scheme 78): Removing Reservoir Tank

Make sure the engine coolant level is between full and low.

Cooling System Trouble Shooting Chart. Scheme 79