Contents Section: Lubrication System All sections

Engine Lubrication System - Lubrication (h4dotc) Subaru Impreza WRX GH

Lubrication System 36 illustrations ~2201 words

SPECIFICATION

Lubrication methodForced lubrication
Oil pumpPump typeTrochoid type
Number of teethInner rotor9
Outer rotor10
Outer rotor diameter x thicknessMm (in)76 x 10 (2.99 x 0.47)
Tip clearance between inner and outer rotorsMm (in)0.04 - 0.14 (0.0016 - 0.0055)
Side clearance between inner rotor and pump caseMm (in)0.02 - 0.07 (0.0008 - 0.0028)
Case clearance between outer rotor and pump caseStandardMm (in)0.10 - 0.175 (0.0039 - 0.0069)
Performance (Oil temperature 80°C (176°F))600 rpmDischarge pressureKPa (kg/cm 2 , psi)98(1.0, 14)
Discharge rateL (US qt, Imp qt)/min.4.6 (4.9, 4.0) or more
5,000 rpmDischarge pressureKPa (kg/cm 2 , psi)294 (3.0, 43)
Discharge rateL (US qt, Imp qt)/min.47.0 (49.7, 41.4) or more
Relief valve working pressureKPa (kg/cm 2 , psi)588 (6.0, 85)
Oil filterFilter typeFull-flow filter type
Filtration areaCm 2 (sq in)Outer diameter: 68 mm (2.68 in)800 (124)
Outer diameter: 65 mm (2.56 in)470 (72.9)
By-pass valve opening pressureKPa (kg/cm 2 , psi)160 (1.63, 23.2)
Outer diameter x widthMm (in)Outer diameter: 68 mm (2.68 in)68 x 65 (2.68 x 2.56)
Outer diameter: 65 mm (2.56 in)65 x 74.4 (2.56 x 2.93)
Installation screw specificationsM 20 x 1.5
Oil pressure switchTypeImmersed contact point type
Operating voltage - power consumption12 V - 3.4 W or less
Warning light operating pressureKPa (kg/cm 2 , psi)14.7 (0.15, 2.1)
Proof pressureKPa (kg/cm 2 , psi)981 (10, 142) or more
Engine oilTotal capacity (Overhaul)L (US qt, lmp qt)5.0 (5.3, 4.4)
When replacing engine oil and oil filterL (US qt, lmp qt)4.2 (4.4, 3.7)
When replacing engine oil onlyL (US qt, lmp qt)4.0 (4.2, 3.5)

ENGINE COOLANT CAPACITY SPECIFICATION

Recommended oil

Items having the API standard SM "Energy Conserving" logo or ILSAC standard GF-4 "Star burst mark" label on the container.

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Scheme 51

The proper viscosity oil helps the engine maintain its ideal temperature, and cranking speed increased by reducing viscosity friction in hot condition.

CAUTIONIt is acceptable to fill an engine with oil of another brand when replacing the oil, but make sure to use an oil with an API standard and SAE viscosity number specified by Subaru.

Note. If the vehicle is used in regions with high temperatures or in other severe environments, use oil with the viscosities shown below. API standard: SM or SL

SAE Viscosity No.: 30, 40, 10W-50, 20W-40, 20W-50

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Scheme 52: COMPONENT

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. If the engine oil is spilt over exhaust pipe or the under cover, wipe it off with cloth to avoid emitting smoke or causing a fire.

SPECIAL TOOL

SPECIAL TOOL SPECIFICATION ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 499587100 OIL SEAL INSTALLER Used for Installing oil seal into oil pump. 18332AA000 OIL FILTER WRENCH Used for removing and installing oil filter. (Outer diameter: 68 mm (2.68 in)) 18332AA010 OIL FILTER WRENCH Used for removing and installing oil filter. (Outer diameter: 65 mm (2.56 in))

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Scheme 53: SPECIAL TOOL

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Scheme 54

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Scheme 55: WIRING DIAGRAM

INSPECTION

StepCheckYesNo
1 CHECK COMBINATION METER. Turn the ignition switch to ON. (engine OFF) Check the warning light in the combination meter.Does the warning light illuminate?Go to step 2.Repair or replace the combination meter. INSPECTION , Combination Meter System . >
2 CHECK HARNESS CONNECTOR BETWEEN COMBINATION METER AND OIL PRESSURE SWITCH. Turn the ignition switch to OFF. Disconnect the connector from oil pressure switch. Turn the ignition switch to ON. Measure the voltage of harness between oil pressure switch connector and chassis ground. Connector & terminal (E11) No. 1 (+) - Chassis ground (-)Is the voltage 10 V or more?Replace the oil pressure switch.Go to step 3.
3 CHECK COMBINATION METER. Turn the ignition switch to OFF. Remove the combination meter. Measure the resistance of combination meter. Terminals (i10) No. 2 - No. 19Is the resistance less than 10 ohms?Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit of harness between combination meter and oil pressure switch Poor contact in combination meter connector Poor contact in oil pressure switch connector Poor contact of coupling connectorRepair or replace the combination meter. INSPECTION , Combination Meter System . >
NOTE
In this case, repair the following item: Open circuit of harness between combination meter and oil pressure switch Poor contact in combination meter connector Poor contact in oil pressure switch connector Poor contact of coupling connector

DIAGNOSTIC PROCEDURE CHART

CAUTIONIf the engine oil is spilt over exhaust pipe or the under cover, wipe it off with cloth to avoid emitting smoke or causing a fire.
  1. Park the vehicle on a level surface.
  2. Remove the oil level gauge and wipe away the oil.
  3. Reinsert the oil level gauge all the way. Be sure that the oil level gauge is correctly inserted and properly orientated.
  4. Remove the oil level gauge again and check the reading. If the engine oil level is below "L" line, add oil to bring the level up to "F" line.
  5. Start the engine and warm it up for a time.
  6. After turning off the engine, wait a few minutes for the oil to return to the oil pan before checking the level.

Note. Just after driving or while the engine is warm, engine oil level shows in the range between "F" line and cutout portion. This is caused by thermal expansion of engine oil. To prevent overfilling of engine oil, do not add oil above "F" line when the engine is cold. As the oil level gauge is used for daily maintenance, the "F" line and "L" line is set assuming that the engine is cold.

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Scheme 56

REPLACEMENT

CAUTIONIf the engine oil is spilt over exhaust pipe or the under cover, wipe it off with cloth to avoid emitting smoke or causing a fire.

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Scheme 57
  1. Set the vehicle on a lift.
  2. Open the engine oil filler cap for quick draining of engine oil.
  3. Lift up the vehicle.
  4. Drain engine oil by loosening the engine oil drain plug. NOTE: Prepare the container for draining of engine oil.
  5. Tighten the engine oil drain plug after draining engine oil. NOTE: Use a new drain plug gasket. Tightening torque: 44 N.m (4.5 kgf-m, 32.5 ft-lb)
  6. Lower the vehicle.
  7. Using engine oil of proper quality and viscosity, fill engine oil through the oil filler duct to the "F" line on oil level gauge. Make sure that the vehicle is parked on a level surface when checking oil level. Recommended oil: Refer to "SPECIFICATION" for the recommended oil. SPECIFICATION, General Description. > Engine oil capacity: Refer to "SPECIFICATION" for the engine oil capacity. SPECIFICATION, General Description. >
  8. Close the engine oil filler cap.
  9. Start the engine, and spreads the oil in engine room.
  10. After the engine stops, recheck the oil level. If necessary, add engine oil up to the "F" line on oil level gauge.

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Scheme 59: REMOVAL

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Scheme 62
  1. Set the vehicle on a lift.
  2. Disconnect the ground cable from the battery.
  3. Lift up the vehicle.
  4. Remove the under cover.
  5. Lower the vehicle.
  6. Remove the radiator. REMOVAL , Radiator . >
  7. Remove the crankshaft position sensor. REMOVAL , Crankshaft Position Sensor . >
  8. Remove the water pump. REMOVAL , Water Pump . >
  9. Remove the crank sprocket. REMOVAL , Crank Sprocket . >
  10. Remove the bolts which install oil pump onto cylinder block. NOTE: When disassembling and checking the oil pump, loosen the relief valve plug before removing the oil pump.
  11. Remove the oil pump by using flat tip screwdriver. CAUTION: Be careful not to scratch mating surfaces of cylinder block and oil pump.
  12. Remove the front oil seal from the oil pump.

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Scheme 63: INSTALLATION

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Scheme 66
  1. Using the ST, install the front oil seal. ST 499587100 OIL SEAL INSTALLER NOTE: Use a new front oil seal.
  2. Apply liquid gasket to the mating surfaces of oil pump. NOTE: Install within 5 min. after applying liquid gasket. Liquid gasket: THREE BOND 1217G (Part No. K0877Y0100) or equivalent
  3. Apply a coat of engine oil to the inside of oil seal.
  4. Install the oil pump to cylinder block. Be careful not to damage the oil seal during installation. NOTE: Make sure the front oil seal lip is not folded. Align the flat surface of oil pump's inner rotor with crankshaft before installation. Use new O-rings. Do not forget to assemble O-rings.
  5. Apply liquid gasket to the three bolts thread shown in figure, (when reuse the bolts) Liquid gasket: THREE BOND 1324 (Part No. 004403042) or equivalent Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb)
  6. Install the crank sprocket. INSTALLATION , Crank Sprocket . >
  7. Install the water pump. INSTALLATION , Water Pump . >
  8. Install the crankshaft position sensor. INSTALLATION , Crankshaft Position Sensor . >
  9. Install the radiator. INSTALLATION , Radiator . >
  10. Lift up the vehicle.
  11. Install the under cover.
  12. Lower the vehicle.
  13. Connect the ground cable to the battery.

DISASSEMBLY

Remove the screw which secures oil pump cover and then disassemble oil pump. Inscribe alignment marks on the inner and outer rotors so that they can be replaced in their original positions during reassembly.

Note. Before disassembling the oil pump, remove the relief valve.

Scheme 67

Scheme 67: DISASSEMBLY

ASSEMBLY

  1. Using the ST, install the front oil seal. ST 499587100 OIL SEAL INSTALLER NOTE: Use a new front oil seal.
  2. Apply a coat of engine oil to inner and outer rotors.
  3. Assemble the inner and outer rotors in their original positions.
  4. Assemble the oil relief valve and install relief valve spring and plug. NOTE: Use a new gasket.
  5. Install the oil pump cover.

Tightening torque

T1: 5.4 N.m (0.55 kgf-m, 4.0 ft-lb)

T2: 44 N.m (4.5 kgf-m, 32.5 ft-lb)

Scheme 68

Scheme 68

TIP CLEARANCE

Measure the tip clearance of rotors. If the clearance is out of specification, replace the rotors as a set.

Tip clearance

Standard

0.04 - 0.14 mm (0.0016 - 0.0055 in)

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Scheme 69: TIP CLEARANCE

CASE CLEARANCE

Measure the clearance between the outer rotor and the oil pump case. If clearance is out of standard, replace the oil pump case.

Case clearance

Standard

0.10 - 0.175 mm (0.0039 - 0.0069 in)

Scheme 70

Scheme 70: CASE CLEARANCE

SIDE CLEARANCE

Measure the gap between the inner rotor and the oil pump case to measure the clearance between the inner rotor and the oil pump cover as shown in the figure. If the clearance is out of specification, replace the rotors and the oil pump case.

Side clearance

Standard

0.02 - 0.07 mm (0.0008 - 0.0028 in)

Scheme 71

Scheme 71: SIDE CLEARANCE

OIL RELIEF VALVE

Check the valve for assembly condition and damage, and the relief valve spring for damage and deterioration. Replace the parts if defective.

Relief valve spring

Free length

73.7 mm (2.902 in)

Installed length

54.7 mm (2.154 in)

Load when installed

93.1 N (9.49 kgf, 20.88 lbf)

OIL PUMP CASE

Check for worn shaft hole, clogged oil passage, worn rotor chamber, cracks and other faults.

FRONT OIL SEAL

Check the front oil seal lips for deformation and hardening, wear.

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Scheme 72

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Scheme 77
  1. Set the vehicle on a lift.
  2. Remove the front wheels.
  3. Disconnect the ground cable from the battery.
  4. Remove the air intake duct.
  5. Remove the air intake boot.
  6. Remove the intercooler. REMOVAL , Intercooler . >
  7. Remove the pitching stopper.
  8. Remove the radiator upper brackets.
  9. Support the engine with a lifting device and wire ropes.
  10. Lift up the vehicle. CAUTION: When lifting up the vehicle, raise up wire ropes at the same time.
  11. Remove the under cover.
  12. Drain the engine oil. REPLACEMENT, Engine Oil. >
  13. Remove the front exhaust pipe. REMOVAL , Front Exhaust Pipe . >
  14. Remove the nuts which install engine mount onto front crossmember.
  15. Remove the bolts which install oil pan on cylinder block with the engine raised up.
  16. Insert an oil pan cutter blade between cylinder block-to-oil pan clearance and remove the oil pan. CAUTION: Do not use a screwdriver or similar tool in place of oil pan cutter.
  17. Remove the oil strainer.
  18. Remove the baffle plate.

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Scheme 78

INSTALLATION

Note. Before installing the oil pan, clean the mating surface of oil pan and engine block.

Scheme 79

Scheme 79: INSTALLATION

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Scheme 80

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Scheme 82
  1. Make sure that the seals (A) are installed securely on the baffle plate in a direction as shown in the figure below. NOTE: Use new seals.
  2. Install the baffle plate. Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb)
  3. Install the oil strainer to the cylinder block. NOTE: Use new O-rings. Tightening torque: 10 N.m (1.0 kgf-m, 7.2 ft-lb)
  4. Tighten the oil strainer stay together with the baffle plate. Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb)
  5. Apply liquid gasket to the mating surfaces of the oil pan, and install the oil pan. NOTE: Use a new gasket. Install within 5 min. after applying liquid gasket. Liquid gasket: THREE BOND 1217G (Part No. K0877Y0100) or equivalent
  6. Tighten the bolts which install oil pan to cylinder block. Tightening torque: T1: 5 N.m (0.5 kgf-m, 3.7 ft-lb) T2: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) T3: 10 N.m (1.0 kgf-m, 7.2 ft-lb)
  7. Lower the engine onto front crossmember.
  8. Tighten the nuts which install engine mount onto front crossmember. Tightening torque: 85 N.m (8.7 kgf-m, 62.7 ft-lb)
  9. Install the front exhaust pipe. INSTALLATION , Front Exhaust Pipe . >
  10. Install the under cover.
  11. Lower the vehicle. CAUTION: When lowering the vehicle, lower the lift up device and wire ropes at the same time.
  12. Remove the lifting device and wire ropes.
  13. Install the pitching stopper. Tightening torque: T1: 50 N.m (5.1 kgf-m, 36.9 ft-lb) T2: 58 N.m (5.9 kgf-m, 42.8 ft-lb)
  14. Install the radiator upper brackets. Tightening torque: 12 N.m (1.2 kgf-m, 8.9 ft-lb)
  15. Install the intercooler. INSTALLATION , Intercooler . >
  16. Install the air intake boot.
  17. Install the air intake duct.
  18. Install the front wheels. Tightening torque: 100 N.m (10.2 kgf-m, 73.8 ft-lb)
  19. Connect the ground cable to the battery.
  20. Refill the engine oil. REPLACEMENT, Engine Oil. >

Visually check that the oil pan, oil strainer, oil strainer stay and baffle plate are not damaged.

Scheme 83

Scheme 83: REMOVAL
  1. Remove the generator from the bracket. REMOVAL , Generator . >
  2. Disconnect the terminal from oil pressure switch.
  3. Remove the oil pressure switch.

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Scheme 84

Scheme 85

Scheme 85: INSTALLATION
  1. Apply liquid gasket to the oil pressure switch threads. Liquid gasket: THREE BOND 1324 (Part No. 004403007) or equivalent
  2. Install the oil pressure switch to the cylinder block. Tightening torque: 25 N.m (2.5 kgf-m, 18.4 ft-lb)
  3. Connect the terminal to the oil pressure switch.
  4. Install the generator to the bracket. INSTALLATION , Generator . >

Check the oil pressure switch installation portion for oil leakage and oil seepage.

REMOVAL

CAUTIONIf the engine oil is spilt over exhaust pipe or the under cover, wipe it off with cloth to avoid emitting smoke or causing a fire.
  1. Set the vehicle on a lift.
  2. Lift up the vehicle.
  3. Remove the under cover.
  4. Remove the oil filter (A) using the ST.

ST 18332AA000 OIL FILTER WRENCH

(Outer diameter: 68 mm (2.68 in) for oil filter)

ST 18332AA010 OIL FILTER WRENCH

(Outer diameter: 65 mm (2.56 in) for oil filter)

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Scheme 86
CAUTIONDo not tighten excessively, or oil may leak.
  1. Clean the oil filter installing surface of cylinder block.
  2. Obtain a new oil filter and apply a thin coat of engine oil to the seal rubber.
  3. Install the oil filter turning it by hand, being careful not to damage the seal rubber. Tighten the oil filter 65 mm (2.56 in) in diameter (approx. 2/3 - 3/4 rotation) after the seal rubber of the oil filter comes in contact with cylinder block or oil cooler. When using a torque wrench, tighten to 12 N.m (1.2 kgf-m, 8.7 ft-lb). Tighten the oil filter 68 mm (2.68 in) in diameter (approx. 1 rotation) after the seal rubber of the oil filter comes in contact with cylinder block or oil cooler. When using a torque wrench, tighten to 14 N.m (1.4 kgf.m, 10.3 ft-lb).
  4. Install the under cover.
  5. Lower the vehicle.
  1. After installing the oil filter, run the engine and make sure that no oil is leaking around seal rubber. NOTE: The filter element and filter case are permanently jointed; therefore, interior cleaning is not necessary.
  2. Check the engine oil level. INSPECTION, Engine Oil. >

Before performing diagnostics, make sure that the engine oil level is correct and no oil leakage exists.

SymptomsPossible causeCorrective action
1. Warning light remains ON.1) Oil pressure switch failureCracked diaphragm or oil leakage within switchReplace.
Broken spring or seized contactsReplace.
2) Low oil pressureClogging of oil filterReplace.
Malfunction of oil by-pass valve in oil filterClean or replace.
Malfunction of oil relief valve in oil pumpClean or replace.
Clogged oil passageClean.
Excessive tip clearance and side clearance of oil pump rotorReplace.
Clogged oil strainer or broken pipeClean or replace.
3) No oil pressureInsufficient engine oil (degradation, etc.)Replace.
Broken pipe of oil strainerReplace.
Stuck oil pump rotorReplace.
2. Warning light does not turn on.1) Malfunction of combination meterReplace.
2) Poor contact of switch contact pointsReplace.
3) Disconnection of wiringRepair.
3. Warning light flickers momentarily.1) Poor contact of terminalsRepair.
2) Defective wiring harnessRepair.
3) Low oil pressureCheck for the same possible causes as listed 1) - 2).

ENGINE COOLING SYSTEM TROUBLESHOOTING CHART