Engine Cooling System (3.0L): Diagnosis Subaru Outback BH

TROUBLE SYMPTOM

1. Radiator main fan does not rotate in low speed under the following conditions: Coolant temperature 95°C (203°F) or more. A/C switch set to OFF.
2. Radiator main fan does not rotate in middle speed under the following conditions: Coolant temperature 95°C (203°F) or less. A/C switch set to ON and A/C temperature at the lowest position.
3. Radiator main fan does not rotate in high speed under the following conditions: Coolant temperature 95°C (203°F) or more. A/C switch set to ON and A/C temperature at the lowest position.

Note. Inspection by your Subaru distributor is required because probable cause is deterioration of multiple parts.

Radiator Main Fan Trouble Shooting Chart (1 Of 5). Scheme 92

Radiator Main Fan Trouble Shooting Chart (2 Of 5). Scheme 93

Radiator Main Fan Trouble Shooting Chart (3 Of 5). Scheme 94

Radiator Main Fan Trouble Shooting Chart (4 Of 5). Scheme 95

Radiator Main Fan Trouble Shooting Chart (5 Of 5). Scheme 96

Radiator Sub Fan Schematic Diagram. Scheme 97

1. Radiator sub fan does not rotate in low speed under the following conditions: Coolant temperature 95°C (203°F) or more. A/C switch set to OFF.
2. Radiator sub fan does not rotate in middle speed under the following conditions: Coolant temperature 95°C (203°F) or less. A/C switch set to ON and A/C temperature at the lowest position.
3. Radiator sub fan does not rotate in high speed under the following conditions: Coolant temperature 95°C (203°F) or more. A/C switch set to ON and A/C temperature at the lowest position.

Note. Inspection by your Subaru distributor is required because probable cause is deterioration of multiple parts.

Radiator Sub Fan Trouble Shooting Chart (1 Of 5). Scheme 98

Radiator Sub Fan Trouble Shooting Chart (2 Of 5). Scheme 99

Radiator Sub Fan Trouble Shooting Chart (3 Of 5). Scheme 100

Radiator Sub Fan Trouble Shooting Chart (4 Of 5). Scheme 101

Radiator Sub Fan Trouble Shooting Chart (5 Of 5). Scheme 102

Scheme 103

Scheme 104

1. Lift-up the vehicle.
2. Remove under cover. (Scheme 103): Removing Under Cover
3. Remove drain cock to drain engine coolant into container. NOTE: Remove radiator cap so that engine coolant will drain faster. (Scheme 104): Removing Drain Cock To Drain Engine Coolant

Scheme 105

1. Fill engine coolant into radiator up to filler neck position. Coolant capacity (fill up to "FULL" level): Approx. 7.7 e (8-1/8 US qt, 6-3/4 Imp qt) CAUTION: The SUBARU Genuine Coolant containing antifreeze and anti-rust agents is especially made for SUBARU engine, which has an aluminum crankcase. Always use SUBARU Genuine Coolant, since other coolant may cause corrosion.
2. Fill engine coolant into reservoir tank up to upper level. (Scheme 105): Filling Coolant Reservoir
3. Attach radiator cap and reservoir tank cap properly.
4. Warm-up engine completely for more than five minutes at 2,000 to 3,000 rpm.
5. If engine coolant level drops in radiator, add engine coolant to filler neck position.
6. If engine coolant level drops from upper level of reservoir tank, add engine coolant to upper level.
7. Attach radiator cap and reservoir tank cap properly.

INSPECTION

1. Check water pump bearing for smooth rotation.
2. Check water pump pulley for abnormalities.

Scheme 106

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Scheme 108

Scheme 109

1. Lift-up the vehicle.
2. Remove under cover. (Scheme 106): Removing Under Cover
3. Drain engine coolant completely. See «DRAINING OF ENGINE COOLANT»(ref-178724-S41423551702005062100000), REPLACEMENT, Engine Coolant. (Scheme 107): Draining Engine Coolant Completely
4. Disconnect radiator outlet hose from thermostat cover. (Scheme 108): Disconnecting Radiator Outlet Hose
5. Remove thermostat cover and gasket, and pull out the thermostat. (Scheme 109): Removing Thermostat Cover & Gasket

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)

Testing Thermostat. Scheme 110

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Scheme 123

1. Disconnect battery ground cable. (Scheme 111): Disconnecting Battery Ground Cable
2. Lift-up the vehicle.
3. Remove under cover. (Scheme 112): Removing Under Cover
4. Drain engine coolant completely. See «DRAINING OF ENGINE COOLANT»(ref-178724-S41423551702005062100000), REPLACEMENT, Engine Coolant. (Scheme 113): Draining Engine Coolant Completely
5. Disconnect connectors of radiator main fan (A) and sub fan (B) motor. (Scheme 114): Disconnecting Main Fan & Sub Fan Motor Connectors
6. Disconnect radiator outlet hose from radiator. (Scheme 115): Disconnecting Radiator Outlet Hose
7. Disconnect ATF cooler hoses from radiator. (Scheme 116): Disconnecting ATF Cooler Hoses
8. Lower the vehicle.
9. Remove air intake duct. (Scheme 117): Removing Air Intake Duct
10. Disconnect over flow hose. (Scheme 118): Disconnecting Over Flow Hose
11. Remove reservoir tank. (Scheme 119): Removing Reservoir Tank
12. Disconnect radiator inlet hoses from radiator. (Scheme 120): Disconnecting Radiator Inlet Hoses
13. Remove radiator upper brackets. (Scheme 121): Removing Radiator Upper Brackets
14. Detach power steering hose from the clip on the radiator. (Scheme 122): Detaching Power Steering Hose From Clip
15. While slightly lifting radiator, slide it to left.
16. Lift radiator up and away from vehicle. (Scheme 123): Removing Radiator

Scheme 124

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Scheme 135

1. Attach radiator mounting cushions to holes on the vehicle. (Scheme 124): 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 125): Installing Radiator
3. Install radiator brackets and tighten bolts. Tightening torque: 12 Nm (1.2 kgf-m, 8.7 ft-lb) (Scheme 126): Installing Radiator Brackets
4. Attach power steering hose to the radiator. (Scheme 127): Attaching Power Steering Hose To Radiator
5. Connect radiator inlet hoses. (Scheme 128): Connecting Radiator Inlet Hoses
6. Install reservoir tank. Tightening torque: 4.9 Nm (0.50 kgf-m, 3.6 ft-lb) (Scheme 129): Installing Reservoir Tank
7. Install air intake duct. (Scheme 130): Installing Air Intake Duct
8. Lift-up the vehicle.
9. Connect ATF cooler hoses. (Scheme 131): Connecting ATF Cooler Hoses
10. Connect connectors to radiator main fan motor (A) and sub fan motor (B). (Scheme 132): Connecting Connectors To Radiator Main Fan & Sub Fan Motor
11. Connect radiator outlet hose. (Scheme 133): Connecting Radiator Outlet Hose
12. Install under cover. (Scheme 134): Installing Under Cover
13. Lower the vehicle.
14. Connect battery ground cable. (Scheme 135): Connecting Battery Ground Cable
15. Fill coolant. See «FILLING OF ENGINE COOLANT»(ref-178724-S19435691382005062100000), REPLACEMENT, Engine Coolant.
16. Check ATF level. See «REPLACEMENT»(ref-175581-S40671530592005042200000), Automatic Transmission Fluid.

Scheme 136

1. Remove radiator cap, top off radiator, and attach tester to radiator in place of cap. (Scheme 136): 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 137

1. Attach radiator cap to tester. (Scheme 137): 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 138

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Scheme 146

1. Disconnect battery ground cable. (Scheme 138): Disconnecting Battery Ground Cable
2. Lift-up the vehicle.
3. Remove under cover. (Scheme 139): Removing Under Cover
4. Drain engine coolant completely. See «Engine Coolant»(ref-178724-S19435691382005062100000).
5. Disconnect connectors of main and sub fan motor. (Scheme 140): Disconnecting Main & Sub Fan Motor Connectors Main fan motor connector Sub fan motor connector
6. Lower the vehicle.
7. Remove air intake duct. (Scheme 141): Removing Air Intake Duct
8. Disconnect over flow hose. (Scheme 142): Disconnecting Over Flow Hose
9. Remove reservoir tank. (Scheme 143): Removing Reservoir Tank
10. Disconnect radiator inlet hoses from radiator. (Scheme 144): Disconnecting Radiator Inlet Hoses
11. Remove radiator sub fan motor assembly. (Scheme 145): Removing Radiator Sub Fan Motor Assembly
12. Remove radiator main fan motor assembly. NOTE: When removing main fan assembly by lifting it upward, main fan shroud will cause interference with coolant suction area. In order to avoid this, shift the main fan assembly over to sub fan side before removing it. (Scheme 146): Removing Radiator Main Fan Motor Assembly

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

Cooling System Trouble Shooting Chart. Scheme 147