Engine Cooling System (sti) Subaru Impreza WRX STI GR

SPECIFICATION

GENERAL SPECIFICATION

COOLANT SPECIFICATION

Scheme 1

Tightening torque: N.m (kgf-m, ft-lb)

T1: First 12 (12, 8.9)

Second 12 (1.2, 8.9)

T2: 12 (1.2, 8.9)

Scheme 2

Tightening torque: N.m (kgf-m, ft-lb)

T1: 3.4 (0.3, 2.5)

T2: 4.41 (0.45, 3.25)

T3: 7.5 (0.8, 5.5)

T4: 12 (1.2, 8.9)

CAUTION

1. Wear appropriate work clothing, including a cap, protective goggles and protective shoes when performing any work.
2. Remove contamination including dirt and corrosion before removal, installation or disassembly.
3. Keep the disassembled parts in order and protect them from dust and dirt.
4. Before removal, installation or disassembly, be sure to clarify the failure. Avoid unnecessary removal, installation, disassembly and replacement.
5. Vehicle components are extremely hot after driving. Be wary of receiving burns from heated parts.
6. Be sure to tighten fasteners including bolts and nuts to the specified torque.
7. Place shop jacks or rigid racks at the specified points.
8. Before disconnecting connectors of sensors or units, be sure to disconnect the ground cable from the battery.
9. Prepare a container and cloth to prevent scattering of engine coolant when performing work where engine coolant can be spilled. If the fuel spills, wipe it off immediately to prevent from penetrating into floor or flowing out for environmental protection.
10. Follow all government and local regulations concerning disposal of refuse when disposing engine coolant.

SPECIAL TOOL

SPECIAL TOOL SPECIFICATION ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 499977100 CRANK PULLEY WRENCH Used to stop rotation of the crank pulley when loosening or tightening crank pulley bolts. 499977500 CAM SPROCKET WRENCH Used for removing and installing intake and exhaust cam sprocket. 1B022XU0 SUBARU SELECT MONITOR III KIT Used for troubleshooting the electrical system

Scheme 3

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Scheme 5

GENERAL TOOL

GENERAL TOOL SPECIFICATION

Scheme 6

OPERATING CONDITION

RADIATOR FAN OPERATION CHART

TROUBLE SYMPTOMS

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

RADIATOR FAN SYSTEM DIAGNOSTIC PROCEDURE

Scheme 7

1. Set the vehicle on a lift.
2. Lift up the vehicle.
3. Remove the under cover.
4. Remove the drain plug to drain engine coolant into container. NOTE: Remove the coolant filler tank cap so that engine coolant will drain faster.
5. Install the drain plug.
6. Install the under cover.

Scheme 8

1. Pour cooling system conditioner through the filler neck of coolant filler tank. Cooling system protective agent: Refer to «SPECIFICATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti__specification) for cooling system protective agent.
2. Fill the engine coolant into coolant filler tank up to the filler neck position. Recommended engine coolant: Refer to «SPECIFICATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti__specification) for recommended engine coolant. Engine coolant level: Refer to «SPECIFICATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti__specification) for engine coolant level. Engine coolant concentration: Refer to «ADJUSTMENT»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) for the recommended engine coolant concentration. CAUTION: Do not confuse the cap of coolant filler tank and cap of radiator. NOTE: When pouring the engine coolant, the radiator side cap must not be removed. The SUBARU Super Coolant contains antifreeze and anti-rust agents, and is especially made for Subaru engines with an aluminum cylinder block. 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 coolant filler tank 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, then open the coolant filler tank cap. If the engine coolant level drops, add engine coolant into the coolant filler tank up to the filler neck position.
6. Perform the procedures 4) and 5) again.
7. Install the coolant filler tank cap and reservoir tank cap properly.
8. Start the engine and operate the heater at maximum hot position and the blower speed setting to TO".
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.
10. Stop the engine and wait until the engine coolant temperature lowers to 30°C (86°F) or less.
11. Open the coolant filler tank cap. If the engine coolant level drops, add engine coolant into the coolant filler tank up to the filler neck position and the reservoir tank to "FULL" level.
12. Install the coolant filler tank 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 ).

PROCEDURE TO ADJUST THE CONCENTRATION OF THE SUBARU SUPER COOLANT

To adjust the concentration of Subaru Super Coolant according to temperature, select the proper Subaru Super Coolant concentration from the table, and add the amount of diluting water corresponding to the required concentration to the Subaru Super Coolant (concentrated type).

TEMPERATURE CHART

Engine coolant and diluting water

Refer to SPECIFICATION for the recommended engine coolant and diluting water.

Scheme 9

Scheme 10

Scheme 11

Scheme 12

1. Remove the radiator. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , Radiator.
2. Remove the V-belts. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , V-belt.
3. Remove the crank pulley. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , Crank Pulley.
4. Remove the timing belt cover. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , Timing Belt Cover.
5. Remove the timing belt. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , Timing Belt.
6. Remove the automatic belt tension adjuster (A).
7. Remove the belt idler (B).
8. Remove the belt idler No. 2 (C).
9. Remove the cam sprocket LH. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , Cam Sprocket.
10. Remove the belt cover No. 2 LH.
11. Remove the tensioner bracket.
12. Disconnect the hose from water pump.
13. Remove the water pump.

Scheme 13

1. Install the water pump onto cylinder block LH. NOTE: Use a new gasket. When installing the water pump, tighten the bolts in two stages in alphabetical sequence as shown in figure. Tightening torque: First: 12 N.m (1.2 kgf-m, 8.9 ft-lb) Second: 12 N.m (1.2 kgf-m, 8.9 ft-lb)
2. Install the hose to water pump.
3. Install the tensioner bracket. Tightening torque: 24.5 N.m (2.5 kgf-m, 18.1 ft-lb)
4. Install the belt cover No. 2 LH. Tightening torque: 5 N.m (0.5 kgf-m, 3.7 ft-lb)
5. Install the cam sprocket LH. Refer to «INSTALLATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , Cam Sprocket.
6. Install the belt idler No. 2 (C). Tightening torque: 39 N.m (4.0 kgf-m, 28.8 ft-lb)
7. Install the belt idler (B). Tightening torque: 25 N.m (2.5 kgf-m, 18.4 ft-lb)
8. Install the automatic belt tension adjuster (A) with the tension rod held by a pin. Refer to «AUTOMATIC BELT TENSION ADJUSTER ASSEMBLY AND BELT IDLER»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , INSTALLATION, Timing Belt.
9. Install the timing belt. Refer to «TIMING BELT»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , INSTALLATION, Timing Belt.
10. Install the timing belt cover. Refer to «INSTALLATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , Timing Belt Cover.
11. Install the crank pulley. Refer to «INSTALLATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , Crank Pulley.
12. Install the V-belts. Refer to «INSTALLATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-mechanical-sti) , V-belt.
13. Install the radiator. Refer to «INSTALLATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , Radiator.

Scheme 14

1. Check the water pump bearing for smooth rotation.
2. Check the water pump pulley for abnormalities.
3. Make sure the impeller is not deformed or damaged.
4. Inspect the clearance between impeller and pump case. Clearance between impeller and pump case: Standard 0.5 - 1.5 mm (0.020 - 0.059 in)
5. 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 15

Scheme 16

1. Set the vehicle on a lift.
2. Lift up the vehicle.
3. Remove the under cover.
4. Drain the engine coolant. Refer to «DRAINING OF ENGINE COOLANT»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , REPLACEMENT, Engine Coolant.
5. Disconnect the radiator outlet hose from thermostat cover.
6. Remove the thermostat cover, and then remove the gasket and thermostat.

Scheme 17

1. Install a gasket to thermostat. NOTE: Use a new gasket.
2. Install the thermostat and thermostat cover. NOTE: Install the parts with the jiggle pin facing upward. Tightening torque: 12 N.m (1.2 kgf-m, 8.9 ft-lb)
3. Connect the radiator outlet hose to thermostat cover.
4. Install the under cover.
5. Lower the vehicle.
6. Fill engine coolant. Refer to «FILLING OF ENGINE COOLANT»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , REPLACEMENT, Engine Coolant.

INSPECTION

Replace the thermostat if the valve does not close completely at an ambient temperature or if any malfunction is detected by the following test.

Scheme 18

1. Inspection method 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 measured value should meet the specification. NOTE: Leave the thermostat in the boiling water for five minutes or more before measuring the valve lift. Hold the thermostat with a wire or the like to avoid contacting the container. Starting temperature to open: 76 - 80°C (169 - 176°F) Full open temperature: 91°C (196°F) Total valve lift: 9.0 mm (0.354 in) or more

REMOVAL

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

1. Set the vehicle on a lift.
2. Disconnect the ground cable from battery.
3. Lift up the vehicle.
4. Remove the under cover.
5. Drain the engine coolant. Refer to «DRAINING OF ENGINE COOLANT»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , REPLACEMENT, Engine Coolant.
6. Disconnect the connectors of main fan motor connector (A) and sub fan motor connector (B).
7. Disconnect the radiator outlet hose from thermostat cover.
8. Lower the vehicle.
9. Remove the air intake duct. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-intake-system-intake-induction-sti) , Air Intake Duct.
10. Remove the reservoir tank. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , Reservoir Tank.
11. Disconnect the radiator inlet hose (A) from the radiator.
12. Disconnect the two coolant filler tank hoses from the radiator.
13. Remove the radiator upper brackets.
14. Move the radiator to the left while lifting it upward.
15. Lift the radiator up and remove the radiator from vehicle.

Scheme 25

1. Attach the radiator lower cushion to the radiator lower bracket.
2. Install the radiator to vehicle. NOTE: Make pins on the lower side of radiator be fitted into the radiator lower cushions.
3. Install the radiator upper brackets. Tightening torque: 12 N.m (1.2 kgf-m, 8.9 ft-lb)
4. Connect the two coolant filler tank hoses to the radiator.
5. Connect the radiator inlet hose (A).
6. Install the reservoir tank. Refer to «INSTALLATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , Reservoir Tank.
7. Install the air intake duct. Refer to «INSTALLATION»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-intake-system-intake-induction-sti) , Air Intake Duct.
8. Lift up the vehicle.
9. Connect the radiator outlet hose.
10. Connect the connectors of main fan motor connector (A) and sub fan motor connector (B).
11. Install the under cover.
12. Lower the vehicle.
13. Connect the ground cable to battery.
14. Fill engine coolant. Refer to «FILLING OF ENGINE COOLANT»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , REPLACEMENT, Engine Coolant.

Scheme 26

1. Remove the coolant filler tank cap, fill the coolant filler tank with engine coolant, then install the radiator cap tester to the filler neck of coolant filler tank.
2. Apply a pressure of 122 kPa (1.2 kg/cm 2 , 18 psi) to the radiator and check the following points: Leakage from the radiator or its vicinity Leakage from the hose or its connections CAUTION: Inspection must be carried out at the side of coolant filler tank, not at the side of radiator. Engine should be turned off. Wipe engine coolant from check points in advance. Be careful of the spurt of engine coolant when removing the radiator cap tester. Be careful not to deform the filler neck of the coolant filler tank when installing and removing the radiator cap tester.

Scheme 27

1. Attach the radiator cap tester to radiator cap.
2. Increase pressure until the radiator cap tester gauge pointer stops. Radiator cap is functioning properly if it holds the service limit pressure for 5 - 6 seconds. Replace the cap if it is opened under a pressure less than the service limit value. Coolant filler tank side Specification: 93 - 123 kPa (0.95 - 1.25 kg/cm 2 , 14 - 18 psi) Service limit: 83 kPa (0.85 kg/cm 2 , 12 psi) Radiator side Specification: 122 - 152 kPa (1.24 - 1.55 kg/cm 2 , 18 - 22 psi) Service limit: 112 kPa (1.14 kg/cm 2 , 16 psi) CAUTION: Be sure to remove foreign matter and rust from the cap in advance. Otherwise, results of pressure test will be incorrect. Do not confuse the cap of coolant filler tank and cap of radiator.

Scheme 28

1. Set the vehicle on a lift.
2. Disconnect the ground cable from battery.
3. Lift up the vehicle.
4. Remove the under cover.
5. Disconnect the main fan motor connector (A).
6. Lower the vehicle.
7. Remove the air intake duct. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-intake-system-intake-induction-sti) , Air Intake Duct.
8. Remove the reservoir tank. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , Reservoir Tank.
9. Remove the bolts which secure the radiator main fan motor assembly and the over flow pipe.
10. Remove the radiator main fan motor assembly from the upper side of the vehicle.

INSTALLATION

Install in the reverse order of removal.

Tightening torque

7.5 N.m (0.8 kgf-m, 5.5 ft-lb)

Scheme 29

Scheme 30

1. Remove the clip which holds the main fan motor connector onto the radiator main fan shroud.
2. Disconnect the radiator main fan from the main fan motor.
3. Disconnect the main fan motor from the radiator main fan shroud.

ASSEMBLY

Assemble in the reverse order of disassembly.

Tightening torque

4.41 N.m (0.45 kgf-m, 3.25 ft-lb)

Tightening torque

3.4 N.m (0.3 kgf-m, 2.5 ft-lb)

Scheme 31

1. Set the vehicle on a lift.
2. Disconnect the ground cable from battery.
3. Lift up the vehicle.
4. Remove the under cover.
5. Disconnect the sub fan motor connector (B).
6. Lower the vehicle.
7. Remove the air intake duct. Refer to «REMOVAL»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/mechanical/#engine-intake-system-intake-induction-sti) , Air Intake Duct.
8. Remove the bolts which secure the radiator sub fan motor assembly and the over flow pipe.
9. Raise the radiator sub fan motor assembly slightly, remove the pin at the lower part of the radiator sub fan motor assembly from the radiator hole, and remove the radiator sub fan motor assembly from the lower side of the vehicle.

Install in the reverse order of removal.

Tightening torque

7.5 N.m (0.8 kgf-m, 5.5 ft-lb)

Scheme 32

1. Remove the clip which holds the sub fan motor connector onto the radiator sub fan shroud.
2. Disconnect the radiator sub fan from the sub fan motor.
3. Disconnect the sub fan motor from the radiator sub fan shroud.

Assemble in the reverse order of disassembly.

Tightening torque

4.41 N.m (0.45 kgf-m, 3.25 ft-lb)

Tightening torque

3.4 N.m (0.3 kgf-m, 2.5 ft-lb)

Scheme 33

1. Pull out the over flow hose (A).
2. Pull out the reservoir tank to the arrow direction while pushing the claw (B).

Install in the reverse order of removal.

Make sure the engine coolant level is between "FULL" and "LOW".

Scheme 34

1. Drain approximately 3.0 l (3.2 US qt, 2.6 lmp qt) of engine coolant. Refer to «DRAINING OF ENGINE COOLANT»(/subaru/impreza-wrx-sti/gr-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system-sti) , REPLACEMENT, Engine Coolant.
2. Disconnect the engine coolant hoses from coolant filler tank.
3. Remove the bolts which secure the coolant filler tank.
4. Remove the coolant filler tank.

Scheme 35

1. Install in the reverse order of removal. Tightening torque: 16 N.m (1.6 kgf-m, 11.8 ft-lb)

ENGINE COOLING SYSTEM INSPECTION CHART

See also:
• COMPULSORY VALVE OPERATION CHECK MODE
• REMOVAL
• REMOVAL
• SPECIFICATION
• ADJUSTMENT