Engine Cooling System - Cooling (H6DO - 3.6L DOHC): Diagnosis Subaru Outback BR

INSPECTION

Operating condition

Radiator fan operates depending on the radiator fan speed related to engine coolant temperature or the radiator fan speed related to A/C compressor load, whichever is higher as a load condition.

Scheme 44

Scheme 45

1. Radiator fan speed related to engine coolant temperature
2. Radiator fan speed related to A/C compressor load

DIAGNOSIS

Radiator main and sub fans do not rotate under the above conditions.

DIAGNOSIS PROCEDURE

Scheme 46

1. Lift up the vehicle.
2. Remove the under cover. Ref. to «REMOVAL»(ref-371913-S09538241932010091900000) , Front Under Cover.
3. Remove the drain plug to drain engine coolant into container. NOTE: Remove the radiator cap so that engine coolant will drain faster.
4. Install the drain plug.
5. Install the under cover. Ref. to «INSTALLATION»(ref-371913-S15712020302010091900000) , Front Under Cover.

Scheme 47

1. Pour cooling system conditioner from the filler neck of the radiator. Cooling system protecting agent: Refer to "SPECIFICATION" for cooling system protecting agent. Ref. to «SPECIFICATION»(ref-371899-S06182442972010091900000) , General Description.
2. Pour engine coolant into the radiator up to the filler neck position. Recommended engine coolant: Refer to "SPECIFICATION" for recommended engine coolant. Ref. to «SPECIFICATION»(ref-371899-S06182442972010091900000) , General Description. Engine coolant level: Refer to "SPECIFICATION" for engine coolant level. Ref. to «SPECIFICATION»(ref-371899-S06182442972010091900000) , General Description. Engine coolant concentration: Refer to "ADJUSTMENT" for the recommended engine coolant concentration. Ref. to «ADJUSTMENT»(ref-371899-S27705026852010091900000) , Engine Coolant. NOTE: The SUBARU Super Coolant is especially made for SUBARU engine, which has an aluminum cylinder block, and contains anti-freeze and anti-rust agents. Always use SUBARU Super Coolant, since other coolant may cause corrosion.
3. Fill engine coolant into the reservoir tank up to "FULL" level.
4. Close the radiator cap and start the engine. Race 5 to 6 times at 3,000 RPM or less, then stop the engine. (Complete this operation within 40 seconds.)
5. Wait for one minute after the engine stops, and open the radiator cap. If the engine coolant level drops, add engine coolant into radiator up to the filler neck position.
6. Perform the procedures 4) and 5) again.
7. Attach the radiator cap and reservoir tank cap properly.
8. Start the engine and operate the heater at maximum hot position and the blower speed setting to "LO".
9. Run the engine at 2,000 RPM or less until radiator fan starts and stops. NOTE: Be careful with the engine coolant temperature gauge to prevent overheating. If the radiator hose becomes hardened with the pressure of engine coolant, air bleeding operation seems to be almost completed.
10. Stop the engine and wait until the engine coolant temperature lowers to 30°C (86°F) or less.
11. Open the radiator cap. If the engine coolant level drops, fill engine coolant up to the radiator filler neck position and to the reservoir tank "FULL" level.
12. Attach the radiator cap and reservoir tank cap properly.
13. Set the heater setting to maximum hot position and the blower speed setting to "LO" and start the engine. Perform racing at 3,000 RPM or less. If the flowing sound is heard from heater core, repeat the procedures from step 9 ).

1. Check the water pump bearing for smooth rotation.
2. Check the water pump sprocket for abnormalities.
3. Make sure the impeller is not abnormally deformed or damaged.
4. After water pump installation, check pulley shaft for engine coolant leaks or noise. If leaks or noise are noted, replace the water pump assembly.

Scheme 48

Scheme 49

1. Lift up the vehicle.
2. Remove the under cover. Ref. to «REMOVAL»(ref-371913-S09538241932010091900000) , Front Under Cover.
3. Drain engine coolant completely. Ref. to «DRAINING OF ENGINE COOLANT»(ref-371899-S23258697372010091900000) , REPLACEMENT, Engine Coolant.
4. Remove the radiator lower hose from the radiator lower and the thermostat cover.
5. Remove the thermostat cover, and then remove the thermostat.

1. Check that the radiator does not have deformation, cracks or damage.
2. Check that the hose has no cracks, damage or loose part.
3. Remove the radiator cap, fill the radiator with engine coolant, and then install the radiator cap tester to the filler neck of radiator.
4. Apply a pressure of 157 kPa (1.6 kgf/cm 2 , 23 psi) to the radiator, and check the following items. Leakage from the radiator or its vicinity Leakage from the hose or its connections CAUTION: Engine should be turned off. Wipe engine coolant from check points in advance. Be careful of engine coolant from spurting out when removing the radiator cap tester. Be careful not to deform the filler neck of radiator when installing and removing the radiator cap tester.

Scheme 50

1. Check that the radiator cap does not have deformation, cracks or damage.
2. Attach the radiator cap tester to radiator cap.
3. Increase pressure until the radiator cap tester gauge needle stops. Radiator cap is functioning properly if it holds the service limit pressure for 5 - 6 seconds. Replace the radiator cap if its valve opens at less than the service limit. Standard: 93 - 123 kPa (0.95 - 1.25 kgf/cm 2 , 14 - 18 psi) Service limit: 83 kPa (0.85 kgf/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 51

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Scheme 53

1. Remove the collector cover. NOTE: Follow the steps below when removing the collector cover. Lift up (A) in two positions at the rear. Moving (B) in two positions at the front toward the vehicle, lift them up.
2. Disconnect the ground cable from battery.
3. Lift up the vehicle.
4. Remove the under cover. Ref. to «REMOVAL»(ref-371913-S09538241932010091900000) , Front Under Cover.
5. Drain engine coolant completely. Ref. to «DRAINING OF ENGINE COOLANT»(ref-371899-S23258697372010091900000) , REPLACEMENT, Engine Coolant.
6. Disconnect the integrated connector of radiator main fan & fan motor and radiator sub fan & fan motor.
7. Lower the vehicle.
8. Remove the air intake duct. Ref. to «REMOVAL»(ref-371896-S20541353172010091900000) , Air Intake Duct.
9. Remove the grille bracket. NOTE: Remove ten clips when removing the grille bracket.
10. Remove the reservoir tank. Ref. to «REMOVAL»(ref-371899-S02283336512010091900000) , Reservoir Tank.
11. Remove radiator upper hoses LH and RH only on radiator side.
12. Remove the ATF hose from the clip of radiator fan shroud.
13. Remove bolts on the upper side of radiator fan shroud.
14. Remove the radiator fan shroud. NOTE: When pulling up the radiator fan shroud, be careful not to damage the radiator hose or AFT hose.

Check that the radiator main fan, radiator main fan shroud and main fan motor do not have deformation, cracks or damage.

Check that the radiator sub fan, radiator sub fan shroud and sub fan motor do not have deformation, cracks or damage.

Scheme 54

1. Pull out the over flow hose.
2. Remove bolts which secure the reservoir tank, and remove the reservoir tank.

1. Check that the reservoir tank does not have deformation, cracks or damage.
2. Check the over flow hose for cracks or damage.
3. Make sure the engine coolant level is between "FULL" and "LOW".

Scheme 55

1. Disconnect the ground cable from battery.
2. Remove the radiator fan control unit. Disconnect the connector (A) from the radiator fan control unit. Remove screws which secure the radiator fan control unit.

ENGINE COOLING SYSTEM INSPECTION CHART