Engine Mechanical - 2.0l Dohc/tc Subaru Impreza WRX GD/GG рестайлинг

SPECIFICATIONS

Engine Specifications

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CAUTION

1. Wear working clothing, including a cap, protective goggles, and protective shoes during operation.
2. Remove contamination including dirt and corrosion before removal, installation or disassembly.
3. Keep the disassembled parts in order and protect them from dust or dirt.
4. Before removal, installation or disassembly, be sure to clarify the failure. Avoid unnecessary removal, installation, disassembly, and replacement.
5. Be careful not to burn your hands, because each part in the vehicle is hot after running.
6. Be sure to tighten fasteners including bolts and nuts to the specified torque.
7. Place shop jacks or safety stands at the specified points.
8. Before disconnecting electrical connectors of sensors or units, be sure to disconnect the negative terminal from battery.
9. All parts should be thoroughly cleaned, paying special attention to the engine oil passages, pistons and bearings.
10. Rotating parts and sliding parts such as piston, bearing and gear should be coated with oil prior to assembly.
11. Be careful not to let oil, grease or coolant contact the timing belt, clutch disc and flywheel.
12. All removed parts, if to be reused, should be re-installed in the original positions and directions.
13. Bolts, nuts and washers should be replaced with new ones as required.
14. Even if necessary inspections have been made in advance, proceed with assembly work while making rechecks.
15. Remove or install the engine in an area where chain hoists, lifting devices, etc. are available for ready use.
16. Be sure not to damage coated surfaces of body panels with tools or stain seats and windows with coolant or oil. Place a cover over fenders, as required, for protection.
17. Prior to starting work, prepare the following: Service tools, clean cloth, containers to catch coolant and oil, wire ropes, chain hoist, transmission jacks, etc.
18. Lift-up or lower the vehicle when necessary. Make sure to support the correct positions.

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GENERAL PURPOSE TOOLS

GENERAL PURPOSE TOOLS

PROCEDURE

It is possible to conduct the following service procedures with engine on the vehicle, however, the procedures described in this section are based on the condition that the engine is removed from the vehicle.

1. V-belt
2. Timing Belt
3. Camshaft
4. Cylinder Head

INSPECTION

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1. After warming-up the engine, turn the ignition switch to OFF.
2. Make sure that the battery is fully charged.
3. Release fuel pressure, see «RELEASING OF FUEL PRESSURE»(/subaru/impreza-wrx/gdgg-2002-2005/remont/fuel-system/#fuel-system-dohctc__releasing-of-fuel-pressure) , Operation, Fuel.
4. Remove all the spark plugs, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/ignition-system/#ignition-system-dohctc__removal) , Spark Plug.
5. Fully open the throttle valve.
6. Check the starter motor for satisfactory performance and operation.
7. Hold the compression gauge tight against the spark plug hole. CAUTION: When using a screw-in type compression gauge, the screw (put into cylinder head spark plug hole) should be less than 18 mm (0.71 in) long.
8. Crank the engine by means of the starter motor, and read the maximum value on the gauge when the pointer is steady.
9. Perform at least two measurements per cylinder, and make sure that the values are correct. Compression (350 RPM and fully open throttle): Standard; 981 - 1,177 kPa (10 - 12 kgf/cm 2 , 142 - 171 psi) Limit; 834 kPa (8.5 kgf/cm 2 , 121 psi) Difference between cylinders; 49 kPa (0.5 kgf/cm 2 , 7 psi)

1. Before checking the idle speed, check the following: Ensure the air cleaner element is free from clogging, ignition timing is correct, spark plugs are in good condition, and that hoses are connected properly. Ensure the malfunction indicator light (CHECK ENGINE) does not illuminate.
2. Warm-up the engine.
3. Stop the engine, and turn the ignition switch to OFF.
4. Insert the cartridge to the SUBARU SELECT MONITOR. (Scheme 497)
5. Connect the SUBARU SELECT MONITOR to the data link connector.
6. Turn the ignition switch to ON, and SUBARU SELECT MONITOR switch to ON.
7. Select {2. Each System Check} in Main Menu.
8. Select {Engine Control System} in Selection Menu.
9. Select {1. Current Data Display & Save} in Engine Control System Diagnosis.
10. Select {1.12 Data Display} in Data Display Menu.
11. Start the engine, and read engine idle speed.
12. Check the idle speed when unloaded (With headlights, heater fan, rear defroster, radiator fan, air conditioning, etc. OFF) Idle speed (No load and gears in neutral: 750 +/- 100 RPM
13. Check the idle speed when loaded (Turn the air conditioning switch to "ON" and operate the compressor for at least one minute before measurement). Idle speed [A/C "ON", no load and gears in neutral]: MT model; 800 +/- 150 RPM AT model; 825 +/- 150 RPM CAUTION: Never rotate the idle adjusting screw. If the idle speed is out of specifications, see «IDLE SPEED»(/subaru/impreza-wrx/gdgg-2002-2005/remont/specifications/#engine-controls-service-adjustment-specifications__idle-speed), Service and Adjustments, Fuel System.

1. Before checking the ignition timing speed, check the following: Ensure the air cleaner element is free from clogging, spark plugs are in good condition, and that hoses are connected properly. Ensure the malfunction indicator light (CHECK ENGINE light) does not illuminate.
2. Warm-up the engine.
3. Stop the engine, and turn the ignition switch to OFF.
4. Insert the cartridge to the SUBARU SELECT MONITOR.
5. Connect the SUBARU SELECT MONITOR to the data link connector.
6. Turn the ignition switch to ON, and SUBARU SELECT MONITOR switch to ON.
7. Select {2. Each System Check} in Main Menu.
8. Select {Engine Control System} in Selection Menu.
9. Select {1. Current Data Display & Save} in Engine Control System Diagnosis.
10. Select {1.12 Data Display} in Data Display Menu.
11. Start the engine, at idle speed and check the ignition timing.

Ignition timing [BTDC/RPM]: 12° +/-3° @ 750

If the timing is not correct, check the ignition control system. See IGNITION TIMING , Service and Adjustments, Ignition System.

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1. Warm-up the engine.
2. Disconnect the brake vacuum hose and install the vacuum gauge to the hose fitting on the manifold.
3. Keep the engine at the idle speed and read the vacuum gauge indication. By observing the gauge needle movement, the internal condition of the engine can be diagnosed as described below.

Vacuum pressure (at idling, A/C "OFF"): Less than -60.0 kPa (-450 mmHg, -17.72 in-Hg)

DIAGNOSIS OF ENGINE CONDITION BY MEASUREMENT OF MANIFOLD VACUUM

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1. Remove the oil pressure switch from engine cylinder block. See «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/lubrication-system/#engine-lubrication-sysyem) , Oil Pressure Switch.
2. Connect the oil pressure gauge hose to cylinder block.
3. Connect the battery ground cable to battery.
4. Start the engine, and measure oil pressure. Oil pressure: 98 kPa (1.0 kg/cm 2 , 14 psi) or more at 800 RPM 294 kPa (3.0 kg/cm 2 , 43 psi) or more at 5,000 RPM CAUTION: If the oil pressure is out of specification, check oil pump, oil filter and lubrication line. See «INSPECTION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/lubrication-system/#engine-lubrication-sysyem) , Engine Lubrication System Troubles. If the oil pressure warning light is turned ON and oil pressure is in specification, replace the oil pressure switch. See «INSPECTION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/lubrication-system/#engine-lubrication-sysyem) , Engine Lubrication System Troubles. NOTE: The specified data is based on an engine oil temperature of 80°C (176°F).
5. After measuring the oil pressure, install the oil pressure switch. See «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/lubrication-system/#engine-lubrication-sysyem) , Oil Pressure Switch. Tightening torque: 25 N.m (2.5 kgf-m, 18.1 ft-lb)

Note. If out of specification, check or replace the pressure regulator and pressure regulator vacuum hose.

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1. Release the fuel pressure, see «RELEASING OF FUEL PRESSURE»(/subaru/impreza-wrx/gdgg-2002-2005/remont/fuel-system/#fuel-system-dohctc__releasing-of-fuel-pressure) , Operation, Fuel.
2. Open the fuel flap lid, and remove the fuel filler cap.
3. Disconnect the fuel delivery hoses from fuel filter, and connect the fuel pressure gauge.
4. Connect the connector of fuel pump relay.
5. Start the engine.
6. Measure fuel pressure while disconnecting the pressure regulator vacuum hose from intake manifold. Fuel pressure: Standard; 284 - 314 kPa (2.9 - 3.2 kgf/cm 2 , 41 - 46 psi)
7. After connecting the pressure regulator vacuum hose, measure fuel pressure. Fuel pressure: Standard; 230 - 260 kPa (2.35 - 2.65 kgf/cm 2 , 33 - 38 psi) NOTE: The fuel pressure gauge registers 10 to 20 kPa (0.1 to 0.2 kgf/cm 2 , 1 to 3 psi) higher than standard values during high-altitude operations.

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1. Set the vehicle onto the lift.
2. Disconnect the ground cable from battery.
3. Remove the air intake duct, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#air-intake-system-h4dotc) , Air Intake Duct.
4. Remove one bolt which secures the timing belt cover (RH).
5. Lift-up the vehicle.
6. Remove the under cover.
7. Loosen the remaining bolts which secure the timing belt cover (RH), then remove the belt cover.
8. Lower the vehicle.
9. When inspecting No. 1 and No. 3 cylinders: Pull out the engine harness connector with bracket from air cleaner upper cover. Remove the air cleaner case, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#air-intake-system-h4dotc) , Air Cleaner. Disconnect the spark plug cords from spark plugs (No. 1 and No. 3 cylinders). Place a suitable container under the vehicle. Disconnect the PCV hose from rocker cover (RH). Remove the bolts, then remove the rocker cover (RH).
10. When inspecting No. 2 and No. 4 cylinders: Disconnect the battery terminal, and then remove the battery and battery carrier. Remove the bolt which secures the engine harness bracket onto body. Disconnect the washer motor connectors. Remove the washer tank mounting bolts. Move the washer tank upward. Disconnect the spark plug cords from spark plugs (No. 2 and No. 4 cylinders). Place a suitable container under the vehicle. Disconnect the PCV hose from rocker cover (LH). Remove the bolts, then remove the rocker cover (LH).
11. Turn the crankshaft pulley clockwise until arrow mark on the camshaft sprocket is set to position shown in the figure. NOTE: Rotate the crankshaft using a socket wrench.
12. Measure No. 1 cylinder intake valve and No. 3 cylinder exhaust valve clearance by using thickness gauge (A). CAUTION: Insert the thickness gauge in as horizontal a direction as possible with respect to the shim. Measure the exhaust valve clearances while lifting-up the vehicle. Valve clearance: Intake: 0.20+/-0.02 mm (0.0079+/-0.0008 in) Exhaust: 0.25+/-0.02 mm (0.0098+/-0.0008 in) NOTE: If the measured value is not within specification, take notes of the value in order to adjust the valve clearance later on.
13. If necessary, adjust the valve clearance, see «ADJUSTMENT»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc__adjustment) .
14. Further turn the crankshaft pulley clockwise. Using the same procedures described previously, then measure valve clearances again. Set the arrow mark on camshaft sprocket to position shown in the figure, and measure No. 2 cylinder exhaust valve and No. 3 cylinder intake valve clearances. Set the arrow mark on camshaft sprocket to position shown in the figure, and measure No. 2 cylinder intake valve and No. 4 cylinder exhaust valve clearances. Set the arrow mark on camshaft sprocket to position shown in the figure, and measure No. 1 cylinder exhaust valve and No. 4 cylinder intake valve clearances.
15. After inspection, install the related parts in the reverse order of removal. Tightening torque: 32 N.m (3.3 kgf-m, 24 ft-lb)

ADJUSTMENT

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1. Measure all valve clearances, see «INSPECTION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Valve Clearance. NOTE: Record each valve clearance after it has been measured.
2. Remove the camshaft, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft.
3. Remove the valve lifter.
4. Measure the thickness of valve lifter with a micrometer.
5. Based on the measured valve clearance and valve lifter thickness, obtain the correct amount of shims from the following table.
6. Set the correct amount of shims to the valve lifter. Selecting Valve Clearance Shims Unit: mm Intake valve: S =(V + T) - 0.20 Exhaust valve: S =(V + T) - 0.25 S: Thickness of valve lifter V: Measured valve clearance T: Thickness of shims AVAILABLE SHIMS Part No. Thickness mm (in) 13228 AB101 4.68 (0.1843) 13228 AB111 4.69 (0.1846) 13228 AB121 4.70 (0.1850) 13228 AB131 4.71 (0.1854) 13228 AB141 4.72 (0.1858) 13228 AB151 4.73 (0.1862) 13228 AB161 4.74 (0.1866) 13228 AB171 4.75 (0.1870) 13228 AB181 4.76 (0.1874) 13228 AB191 4.77 (0.1878) 13228 AB201 4.78 (0.1882) 13228 AB211 4.79 (0.1886) 13228 AB221 4.80 (0.1890) 13228 AB231 4.81 (0.1894) 13228 AB241 4.82 (0.1898) 13228 AB251 4.83 (0.1902) 13228 AB261 4.84 (0.1906) 13228 AB271 4.85 (0.1909) 13228 AB281 4.86 (0.1913) 13228 AB291 4.87 (0.1917) 13228 AB301 4.88 (0.1921) 13228 AB311 4.89 (0.1925) 13228 AB321 4.90 (0.1929) 13228 AB331 4.91 (0.1933) 13228 AB341 4.92 (0.1937) 13228 AB351 4.93 (0.1941) 13228 AB361 4.94 (0.1945) 13228 AB371 4.95 (0.1949) 13228 AB381 4.96 (0.1953) 13228 AB391 4.97 (0.1957) 13228 AB401 4.98 (0.1961) 13228 AB411 4.99 (0.1965) 13228 AB421 5.00 (0.1969) 13228 AB431 5.01 (0.1972) 13228 AB441 5.02 (0.1976) 13228 AB451 5.03 (0.1980) 13228 AB461 5.04 (0.1984) 13228 AB471 5.05 (0.1988) 13228 AB481 5.06 (0.1992) 13228 AB491 5.07 (0.1996) 13228 AB501 5.08 (0.2000) 13228 AB511 5.09 (0.2004) 13228 AB521 5.10 (0.2008) 13228 AB531 5.11 (0.2012) 13228 AB541 5.12 (0.2016) 13228 AB551 5.13 (0.2020) 13228 AB561 5.14 (0.2024) 13228 AB571 5.15 (0.2028) 13228 AB581 5.16 (0.2031) 13228 AB591 5.17 (0.2035) 13228 AB601 5.18 (0.2039) 13228 AB611 5.19 (0.2043) 13228 AB621 5.20 (0.2047) 13228 AB631 5.21 (0.2051) 13228 AB641 5.22 (0.2055) 13228 AB651 5.23 (0.2059) 13228 AB661 5.24 (0.2063) 13228 AB671 5.25 (0.2067) 13228 AB681 5.26 (0.2071) 13228 AB691 5.27 (0.2075) 13228 AB701 4.38 (0.1724) 13228 AB711 4.40 (0.1732) 13228 AB721 4.42 (0.1740) 13228 AB731 4.44 (0.1748) 13228 AB741 4.46 (0.1756) 13228 AB751 4.48 (0.1764) 13228 AB761 4.50 (0.1771) 13228 AB771 4.52 (0.1780) 13228 AB781 4.54 (0.1787) 13228 AB791 4.56 (0.1795) 13228 AB801 4.58 (0.1803) 13228 AB811 4.60 (0.1811) 13228 AB821 4.62 (0.1819) 13228 AB831 4.64 (0.1827) 13228 AB841 4.66 (0.1835) 13228 AB851 5.29 (0.2083) 13228 AB861 5.31 (0.2091) 13228 AB871 5.33 (0.2098) 13228 AB881 5.35 (0.2106) 13228 AB891 5.37 (0.2114) 13228 AB901 5.39 (0.2122) 13228 AB911 5.41 (0.2126) 13228 AB921 5.43 (0.2138) 13228 AB931 5.45 (0.2146) 13228 AB941 5.47 (0.2154) 13228 AB951 5.49 (0.2161) 13228 AB961 5.51 (0.2169) 13228 AB971 5.53 (0.2177) 13228 AB981 5.55 (0.2185) 13228 AB991 5.57 (0.2193) 13228 AC001 5.59 (0.2201) 13228 AC011 5.61 (0.2209) 13228 AC021 5.63 (0.2217) 13228 AC031 5.65 (0.2224)
7. Inspect all valves for clearance again at this stage. If the valve clearance is not correct, repeat the procedure over again from the first step.
8. After inspection, install the related parts in the reverse order of removal.

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1. Set the vehicle on lift arms.
2. Open the front hood fully and support with stay.
3. Raise the rear seat, and turn the floor mat up.
4. Release fuel pressure, see «RELEASING OF FUEL PRESSURE»(/subaru/impreza-wrx/gdgg-2002-2005/remont/fuel-system/#fuel-system-dohctc__releasing-of-fuel-pressure) , Operation, Fuel. Disconnect the fuel pump relay connector. Start the engine, and run until stalls. After the engine stalls, crank it for five seconds more. Turn the ignition switch to "OFF".
5. Remove the filler cap.
6. Disconnect the ground cable from battery.
7. Remove the radiator from vehicle, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/cooling-fan/#engine-cooling-system) , Radiator.
8. Remove the coolant filler tank, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/cooling-fan/#engine-cooling-system) , Coolant Filler Tank.
9. Collect refrigerant, and remove the pressure hoses. Place and connect the attachment hose to the refrigerant recycle system. Collect the refrigerant from A/C system. Disconnect the A/C pressure hoses from A/C compressor.
10. Remove the intercooler, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#air-intake-system-h4dotc) , Intercooler.
11. Disconnect the following connectors and cable. Engine harness connector Engine ground terminal Engine harness connector Generator connector, terminal and A/C compressor connectors Accelerator cable Clutch release spring
12. Disconnect the following hoses. Brake booster vacuum hose Heater inlet outlet hose
13. Remove the power steering pump from bracket. Loosen lock bolt and slider bolt, and remove the front side V-belt. See «FRONT SIDE BELT»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc__front-side-belt) , Removal, V-belt. Disconnect the power steering switch connector. Remove the pipe with bracket from intake manifold. Remove the power steering pump from engine. Remove the power steering tank from the bracket by pulling it upward. Place the power steering pump on the right side wheel apron.
14. Lift-up the vehicle.
15. Remove the ATF cooler pipe from frame (AT vehicles)
16. Remove the center exhaust pipe, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/exhaust/#exhaust-system-h4dotc) , Center Exhaust Pipe.
17. Remove the nuts which hold lower side of transmission to engine.
18. Remove the nuts which install the front cushion rubber onto front crossmember.
19. Lower the vehicle.
20. Separate the clutch release fork from release bearing (MT vehicles) Remove the clutch operating cylinder from transmission. Remove the plug using a 10 mm hexagon wrench. Screw the 6 mm diameter bolt into release fork shaft, and remove it. Raise the release fork and unfasten the release bearing tabs to free release fork. CAUTION: Step (4) is required to prevent interference with engine when removing the engine from transmission.
21. Separate the torque converter clutch from drive plate (AT vehicles) Lower the vehicle. Remove the service hole plug. Remove the bolts which hold torque converter clutch to drive plate. Remove the other bolts while rotating the engine using ST. ST 499977400 CRANK PULLEY WRENCH
22. Remove the pitching stopper.
23. Disconnect the fuel delivery hose, return hose and evaporation hose. CAUTION: Catch fuel from hose into container. Disconnect the hose with its end wrapped with cloth to prevent fuel from splashing.
24. Remove the fuel filter and bracket.
25. Support the engine with a lifting device and wire ropes.
26. Support the transmission with a floor jack. CAUTION: Before moving the engine away from transmission, check to be sure no work has been overlooked. Doing this is very important in order to facilitate re-installation and because transmission lowers under its own weight.
27. Separation of engine and transmission. Remove the starter, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/starter/#starters-except-outback-sport__removal) , Starter. Install the ST to torque converter clutch case (AT vehicles) ST 498277200 STOPPER SET Remove the bolts which hold right upper side of transmission to engine.
28. Remove the engine from vehicle. Slightly raise the engine. Raise the transmission with floor jack. Move the engine horizontally until the mainshaft is withdrawn from clutch cover. Slowly move the engine away from engine compartment. CAUTION: Be careful not to damage adjacent parts or body panels with crank pulley, oil pressure gauge, etc.
29. Remove the front cushion rubbers.

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1. Install the clutch release fork and bearing onto transmission (MT vehicles) Remove the release bearing from clutch cover with flat type screw driver. Install the release bearing on transmission. Install the release fork into release bearing tab. Apply grease to the specified points. Spline; FX2200 Shaft; SUNLIGHT 2 Insert the release fork shaft into release fork. CAUTION: Make sure the cutout portion of release fork shaft contacts spring pin. Tighten the plug. Tightening torque: 44 N.m (4.5 kgf-m, 32.5 ft-lb)
2. Install the front cushion rubbers to engine. Tightening torque: 34 N.m (3.5 kgf-m, 25.3 ft-lb)
3. Install the engine onto transmission. Position the engine in engine compartment and align it with transmission. CAUTION: Be careful not to damage adjacent parts or body panels with crank pulley, oil pressure gauge, etc. Apply a small amount of grease to splines of mainshaft (MT vehicles)
4. Tighten the bolts which hold right upper side of transmission to engine. Tightening torque: 50 N.m (5.1 kgf-m, 36.9 ft-lb)
5. Remove the lifting device and wire ropes.
6. Remove the floor jack.
7. Install the pitching stopper. Tightening torque: T1: 50 N.m (5.1 kgf-m, 37 ft-lb) T2: 58 N.m (5.9 kgf-m, 43 ft-lb)
8. Remove the ST from torque converter clutch case (AT vehicles). NOTE: Be careful not to drop the ST into the torque converter clutch case when removing ST. ST 498277200 STOPPER SET
9. Install the starter, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/starter/#starters-except-outback-sport__installation) , Starter.
10. Install the torque converter clutch onto drive plate (AT vehicles). Tighten the bolts which hold torque converter clutch to drive plate. Tighten other bolts while rotating the engine by using ST. CAUTION: Be careful not to drop bolts into the torque converter clutch housing. ST 499977300 CRANK PULLEY WRENCH Tightening torque: 25 N.m (2.5 kgf-m, 18.1 ft-lb) Clog the service hole with plug.
11. Install the fuel filter and bracket.
12. Install the power steering pump on bracket. Install the power steering tank on bracket. Install the power steering pump. Tightening torque: 20.1 N.m (2.05 kgf-m, 14.8 ft-lb) Install the power steering pipe bracket on right side intake manifold, and install the spark plug codes. Connect the power steering switch connector. Install the front side V-belt, and adjust it. See «FRONT SIDE BELT»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Installation, V-belt.
13. Lift-up the vehicle.
14. Tighten the nuts which hold lower side of transmission to engine. Tightening torque: 50 N.m (5.1 kgf-m, 36.9 ft-lb)
15. Tighten the nuts which install the front cushion rubber onto crossmember. Tightening torque: 83 N.m (8.5 kgf-m, 61 ft-lb) CAUTION: Make sure the front cushion rubber mounting bolts (A) and locator (B) are securely installed.
16. Install the ATF cooler pipe to frame (AT vehicles).
17. Install the center exhaust pipe, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/exhaust/#exhaust-system-h4dotc) , Center Exhaust Pipe.
18. Lower the vehicle.
19. Connect the following hoses: Fuel delivery hose, return hose and evaporation hose Heater inlet and outlet hoses Brake booster vacuum hose
20. Connect the following connectors and terminals: Engine ground terminal Engine harness connectors Generator connector Generator terminal Tightening torque: 5.88 N.m (0.60 kgf-m, 4.34 ft-lb) A/C compressor connectors
21. Connect the following cables: Accelerator cable Clutch release spring CAUTION: After connecting each cable, adjust them.
22. Install the air intake system. Install the intercooler, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#air-intake-system-h4dotc) , Intercooler. Install the air cleaner element and air cleaner upper cover. Install the engine harness connector bracket. Install the filler hose to air cleaner case.
23. Install the A/C pressure hoses. CAUTION: Use new O-rings. Tightening torque: 25 N.m (2.5 kgf-m, 18.1 ft-lb)
24. Install the radiator, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/cooling-fan/#engine-cooling-system) , Radiator.
25. Install the coolant filler tank, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/cooling-fan/#engine-cooling-system) , Coolant Filler Tank.
26. Install the window washer tank.
27. Install the battery in the vehicle, and connect cables.
28. Fill coolant, see «FILLING OF ENGINE COOLANT»(/subaru/impreza-wrx/gdgg-2002-2005/remont/cooling-fan/#engine-cooling-system) , Replacement, Engine Coolant.
29. Charge the A/C system with refrigerant. See «REFRIGERANT CHARGING PROCEDURE»(/subaru/impreza-wrx/gdgg-2002-2005/remont/manual-hvac-system/#hvac) , HVAC.
30. Remove the front hood stay, and close the front hood.
31. Take off the vehicle from lift arms.

REMOVAL

1. Remove the engine assembly, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc__removal) , Engine Assembly.
2. Remove the engine mounting from engine assembly.

INSTALLATION

Install in the reverse order of removal.

Tightening torque

1. Engine mounting: 34 N.m (3.5 kgf-m, 25.3 ft-lb)

Make sure there are no cracks or other damage.

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1. After removing the engine from the body, secure it in the ST shown below. ST1 498457000 ENGINE STAND ADAPTER RH ST2 498457100 ENGINE STAND ADAPTER LH ST3 499817000 ENGINE STAND
2. In this section the procedures described under each index are all connected and stated in order. It will be the complete procedure for overhauling of the engine itself when you go through all steps in the process. Therefore, in this section, to conduct the particular procedure within the flow of a section, you need to go back and conduct the procedure described previously in order to do that particular procedure.

FRONT SIDE BELT

Note. Perform the following procedures 1) to 4) with the engine installed to the body.

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1. Remove the V-belt cover.
2. Loosen the lock bolt (A).
3. Loosen the slider bolt (B).
4. Remove the front side belt (C).

Scheme 571

Scheme 572

1. Loosen the lock nut (A).
2. Loosen the slider bolt (B).
3. Remove the A/C belt.
4. Remove the A/C belt tensioner.

1. Install a belt, and tighten the slider bolt so as to obtain the specified belt tension. See «A/C COMPRESSOR, ALTERNATOR & POWER STEERING BELT»(/subaru/impreza-wrx/gdgg-2002-2005/remont/accessory-drive-belts/#specifications-drive-belt-routing__ac-compressor-alternator-power-steering) , Drive Belt Adjustment.
2. Tighten the lock bolt (A)
3. Tighten the slider bolt (B).

Tightening torque

Scheme 573

1. Lock bolt through bolt: 25 N.m (2.5 kgf-m, 18 ft-lb)
2. Slider bolt: 8 N.m (0.8 kgf-m, 5.5 ft-lb )

Scheme 574

1. Install a belt, and tighten the slider bolt (B) so as to obtain the specified belt tension. See «A/C COMPRESSOR, ALTERNATOR & POWER STEERING BELT»(/subaru/impreza-wrx/gdgg-2002-2005/remont/accessory-drive-belts/#specifications-drive-belt-routing__ac-compressor-alternator-power-steering) , Drive Belt Adjustment.
2. Tighten the lock nut (A). Tightening torque: Lock nut (A): 22.6 N.m (2.3 kgf-m, 16.6 ft-lb)

Scheme 575

1. Replace the belts, if cracks, fraying or wear is found.
2. Check the drive belt tension and adjust it if necessary by changing generator installing position and/or idler pulley installing position. Belt tension (A) (A) Replaced: 7-9 mm (0.276-0.354 in) Reused: 9-11 mm (0.354-0.433 in) (B)* Replaced: 7.5-8.5 mm (0.295-0.335 in) Reused: 9.0-10.0 mm (0.354-0.394 in) *: With Air conditioner

Scheme 576

1. Remove the V-belt, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-Belt.
2. Remove the crankshaft pulley bolt. To lock crankshaft, use ST. ST 499977400 CRANK PULLEY WRENCH
3. Remove the crankshaft pulley.

Scheme 577

1. Install the crankshaft pulley.
2. Install the pulley bolt. To lock the crankshaft, use ST. ST 499977400 CRANK PULLEY WRENCH Clean the crankshaft pulley thread using an air gun. Apply engine oil to the crankshaft pulley bolt seat and thread. Tighten the bolts temporarily with tightening torque of 44 N.m (4.5 kgf-m, 33 ft-lb). Tighten the crankshaft pulley bolts. Tightening torque: 127 N.m (13 kgf-m, 94.0 ft-lb)
3. Confirm that the tightening angle of the crankshaft pulley bolt is 45 degrees or more. If less than 45 degrees, conduct the following procedures (1) through (4).

Scheme 578

Scheme 579

1. Replace the crankshaft pulley bolts and clean them. Crankshaft pulley bolt: 12369AA011
2. Clean the crankshaft thread using an air gun.
3. Tighten the bolts temporarily with tightening torque of 44 N.m (4.5 kgf-m, 33 ft-lb).
4. Tighten the crankshaft pulley bolts for a further angle of 45 - 60 degrees. CAUTION: Conduct the tightening procedures by confirming the turning angle of the crankshaft pulley bolt referring to the gauge indicated on the belt cover.
5. Install the A/C belt tensioner.
6. Install the V-belt, see «FRONT SIDE BELT»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Installation, V-belt.

1. Make sure the V-belt is not worn or otherwise damaged.
2. Check the tension of the belt. See «A/C COMPRESSOR, ALTERNATOR & POWER STEERING BELT»(/subaru/impreza-wrx/gdgg-2002-2005/remont/accessory-drive-belts/#specifications-drive-belt-routing__ac-compressor-alternator-power-steering) , Drive Belt Adjustment.

Scheme 580

1. Remove the V-belt, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-Belt.
2. Remove the crankshaft pulley, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
3. Remove the left-hand belt cover (A).
4. Remove the right-hand belt cover (B).
5. Remove the front belt cover (C).

Scheme 581

1. Install the front belt cover (C). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb)
2. Install the right-hand belt cover (B). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb)
3. Install the left-hand belt cover (A). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb)
4. Install the crankshaft pulley, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
5. Install the V-belt, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-belt.

Make sure the cover is not damaged.

Scheme 582

Scheme 583

Scheme 584

Scheme 585

Scheme 586

Scheme 587

Scheme 588

Scheme 589

Scheme 590

1. Remove the V-belt, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-Belt.
2. Remove the crankshaft pulley, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
3. Remove the belt cover, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
4. Remove the timing belt guides (MT vehicle).
5. If the alignment mark and/or arrow mark (which indicates rotation direction) on timing belt fade away, put new marks before removing the timing belt as follows: Turn the crankshaft using ST, and align alignment marks on crankshaft sprocket, left-hand intake camshaft sprocket, left-hand exhaust camshaft sprocket, right-hand intake camshaft sprocket and right hand exhaust camshaft sprocket with notches of belt cover and cylinder block. ST 499987500 CRANKSHAFT SOCKET Using white paint, put alignment and/or arrow marks on the timing belts in relation to the sprockets. Z 1 : 54.5 tooth length Z 2 : 51 tooth length Z 3 : 28 tooth length
6. Remove the belt idler (A).
7. Remove the timing belt. CAUTION: After the timing belt has been removed, never rotate the intake and exhaust, camshaft sprocket. If the camshaft sprocket is rotated, the intake and exhaust valve heads strike together and valve stems are bent.

Scheme 591

Scheme 592

Scheme 593

1. Remove the belt idler (B) and (C).
2. Remove the belt idler No. 2.
3. Remove the automatic belt tension adjuster assembly.

Scheme 594

Scheme 595

Scheme 596

Scheme 597

Scheme 598

1. Preparation for installation of automatic belt tension adjuster assembly: CAUTION: Always use a vertical type pressing tool to move the adjuster rod down. Do not use a lateral type vise. Push the adjuster rod vertically. Be sure to slowly move the adjuster rod down applying a pressure of 294 N (30 kgf, 66 lb). Press-in the push adjuster rod gradually taking more than three minutes. Do not allow press pressure to exceed 9,807 N (1,000 kgf, 2,205 lb). Press the adjuster rod as far as the end surface of the cylinder. Do not press the adjuster rod into the cylinder. Doing so may damage the cylinder. Do not release the press pressure until stopper pin is completely inserted. Attach the automatic belt tension adjuster assembly to the vertical pressing tool. Slowly move the adjuster rod down with a pressure of 294 N (30 kgf, 66 lb) until the adjuster rod is aligned with the stopper pin hole in the cylinder. With a 2 mm (0.08 in) diameter stopper pin or a 2 mm (0.08 in) (nominal) diameter hex bar wrench inserted into the stopper pin hole in the cylinder, secure the adjuster rod.
2. Install the automatic belt tension adjuster assembly. Tightening torque: 39 N.m (4.0 kgf-m, 28.9 ft-lb)
3. Install the belt idler No. 2. Tightening torque: 39 N.m (4.0 kgf-m, 28.9 ft-lb)
4. Install the belt idler. Tightening torque: 39 N.m (4.0 kgf-m, 28.9 ft-lb)

Scheme 599

Scheme 600

Scheme 601

Scheme 602

Scheme 603

Scheme 604

Scheme 605

Scheme 606

Scheme 607

Scheme 608

Scheme 609

Scheme 610

Scheme 611

Scheme 612

Scheme 613

Scheme 614

Scheme 615

Scheme 616

1. Preparation for installation of automatic belt tension adjuster assembly. See «AUTOMATIC BELT TENSION ADJUSTER ASSEMBLY AND BELT IDLER»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc), Installation, Timing Belt Assembly.
2. Crankshaft and camshaft sprocket alignment. Align mark (A) on the crankshaft sprocket with mark on the oil pump cover at cylinder block. Align single line mark (A) on the right-hand exhaust camshaft sprocket with notch (B) on belt cover. Align single line mark (A) on the right-hand intake camshaft sprocket with notch (B) on belt cover. Make sure double lines (C) on intake camshaft and exhaust camshaft sprockets are aligned. (Scheme 601) Align single line mark (A) on left-hand exhaust camshaft sprocket with notch (B) on belt cover by turning the sprocket counterclockwise (as viewed from front of engine). Align single line mark (A) on left-hand intake camshaft sprocket with notch (B) on belt cover by turning the sprocket clockwise (as viewed from front of engine). Ensure double lines (C) on intake and exhaust camshaft sprockets are aligned. (Scheme 603) Ensure camshaft and crankshaft sprockets are positioned properly. CAUTION: Intake and exhaust camshafts for this DOHC engine can be independently rotated with the timing belts removed. As can be seen from the figure, if the intake and exhaust valves are lifted simultaneously, their heads will interfere with each other, resulting in bent valves. When the timing belts are not installed, four camshafts are held at the "zero-lift" position, where all cams on camshafts do not push the intake and exhaust valves down (Under this condition, all valves remain unlifted). When the camshafts are rotated to install the timing belts, No. 2 intake and No. 4 exhaust cam of left-hand camshafts are held to push their corresponding valves down (Under this condition, these valves are held lifted). Right-side camshafts are held so that their cams do not push valves down. Left-hand camshafts must be rotated from the "zero-lift" position to the position where the timing belt is to be installed at as small an angle as possible, in order to prevent mutual interference of intake and exhaust valve heads. Do not allow the camshafts to rotate in the direction shown in the figure as this causes both intake and exhaust valves to lift simultaneously, resulting in interference with their heads.
3. Installation of timing belt: Align the alignment mark on the timing belt with marks on the sprockets in the alphabetical order shown in the figure. While aligning marks, position the timing belt properly. CAUTION: Disengagement of more than three timing belt teeth may result in interference between the valve and piston. Ensure the belt's rotating direction is correct.
4. Install the belt idlers. Tightening torque: 39 N.m (4.0 kgf-m, 28.9 ft-lb) CAUTION: Make sure that the marks on the timing belt and sprockets are aligned.
5. After ensuring that the marks on the timing belt and sprockets are aligned, remove the stopper pin from tensioner adjuster.
6. Install the timing belt guide (MT vehicle). Temporarily tighten the bolts. Check and adjust clearance between the timing belt and timing belt guides. Clearance: 1.0 +/- 0.5 mm (0.039 +/- 0.020 in) Tighten the remaining bolts. Tightening torque: 9.8 N.m (1.0 kgf-m, 7.2 ft-lb)
7. Install the belt cover, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc), Belt Cover.
8. Install the crankshaft pulley, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc), Crankshaft Pulley.
9. Install the V-belt, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc), V-belt.

Scheme 617

1. Check the timing belt teeth for breaks, cracks, and wear. If any fault is found, replace the belt.
2. Check the condition of back side of belt; if any crack is found, replace the belt. CAUTION: Be careful not to let oil, grease or coolant contact the belt. Remove quickly and thoroughly if this happens. Do not bend the belt sharply. Bending radius: h = 60 mm (2.36 in) or more

Scheme 618

1. Visually check the oil seals for leaks, and rod ends for abnormal wear or scratches. If necessary, replace the automatic belt tension adjuster assembly. CAUTION: Slight traces of oil at rod's oil seal does not indicate the a problem.
2. Check that the adjuster rod does not move when a pressure of 294 N (30 kgf, 66 lb) is applied to it. This is to check adjuster rod stiffness.
3. If the adjuster rod is not stiff and moves freely when applying 294 N (30 kgf, 66 lb), check it using the following procedures: Slowly press the adjuster rod down to the end surface of the cylinder. Repeat this motion 2 or 3 times. With the adjuster rod moved all the way up, apply a pressure of 294 N (30 kgf, 66 lb) to it. Check the adjuster rod stiffness. If the adjuster rod is not stiff and moves down, replace the automatic belt tension adjuster assembly with a new one. CAUTION: Always use a vertical type pressing tool to move the adjuster rod down. Do not use a lateral type vise. Push the adjuster rod vertically. Press-in the push adjuster rod gradually taking more than three minutes. Do not allow press pressure to exceed 9,807 N (1,000 kgf, 2,205 lb). Press the adjuster rod as far as the end surface of the cylinder. Do not press the adjuster rod into the cylinder. Doing so may damage the cylinder. Measure the extension of rod beyond the body. If it is not within specifications, replace with a new one. Rod extension: H = 5.7 +/- 0.5 mm (0.224 +/- 0.020 in)

BELT TENSION PULLEY

1. Check the mating surfaces of timing belt and contact point of adjuster rod for abnormal wear or scratches. Replace the belt tension pulley if faulty.
2. Check the belt tension pulley for smooth rotation. Replace if noise or excessive play is noted.
3. Check the belt tension pulley for grease leakage.

BELT IDLER

1. Check the idler for smooth rotation. Replace if noise or excessive play is noted.
2. Check the outer contacting surfaces of idler pulley for abnormal wear and scratches.
3. Check the idler for grease leakage.

Scheme 619

1. Remove the V-belt, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-Belt.
2. Remove the crankshaft pulley, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
3. Remove the belt cover, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
4. Remove the timing belt assembly, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
5. Remove the camshaft position sensor, see «REMOVAL & INSTALLATION (IMPREZA WRX 2.0L)»(/subaru/impreza-wrx/gdgg-2002-2005/remont/removal-installation/#engine-controls-removal-installation-impreza-outback-sport) , Camshaft Position Sensor.
6. Remove the camshaft sprockets. To lock the camshaft, use ST. ST 18231AA010 CAMSHAFT SPROCKET WRENCH (Intake LH) ST 499207400 CAMSHAFT SPROCKET WRENCH (Except intake LH)

Scheme 620

1. Install the camshaft sprocket No. 1. and No. 2. To lock camshaft, use ST. ST 18231AA010 CAMSHAFT SPROCKET WRENCH (Intake LH) ST 499207400 CAMSHAFT SPROCKET WRENCH (Except intake LH) Tightening torque: 98 N.m (10 kgf-m, 72.4 ft-lb) CAUTION: Do not confuse left and right side intake camshaft sprockets during installation. The intake camshaft sprocket LH is identified by a projection used to monitor camshaft position sensor.
2. Install the camshaft position sensor, see «REMOVAL & INSTALLATION (IMPREZA WRX 2.0L)»(/subaru/impreza-wrx/gdgg-2002-2005/remont/removal-installation/#engine-controls-removal-installation-impreza-outback-sport) , Installation, Camshaft Position Sensor.
3. Install the timing belt assembly, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
4. Install the belt cover, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
5. Install the crankshaft pulley, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
6. Install the V-belt, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-belt.

1. Check the sprocket teeth for abnormal wear and scratches.
2. Make sure there is no free play between sprocket and key.
3. Check the crankshaft sprocket notch used for sensor for damage and contamination of foreign matter.

Scheme 621

1. Remove the V-belt, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-Belt.
2. Remove the crankshaft pulley, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
3. Remove the belt cover, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
4. Remove the timing belt assembly, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
5. Remove the camshaft sprocket, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft Sprocket.
6. Remove the crankshaft sprocket.

Scheme 622

1. Install the crankshaft sprocket.
2. Install the camshaft sprockets, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft Sprocket.
3. Install the timing belt assembly, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
4. Install the belt cover, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
5. Install the crankshaft pulley, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
6. Install the V-belt, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-belt.

1. Check the sprocket teeth for abnormal wear and scratches.
2. Make sure there is no free play between sprocket and key.
3. Check the crankshaft sprocket notch used for sensor for damage and contamination of foreign matter.

Scheme 623

Scheme 624

Scheme 625

Scheme 626

Scheme 627

1. Remove the V-belt, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-Belt.
2. Remove the crankshaft pulley, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
3. Remove the belt cover, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
4. Remove the timing belt assembly, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
5. Remove the camshaft sprocket, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft Sprocket.
6. Remove the crankshaft sprocket, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Sprocket.
7. Remove the right-hand belt cover No.2.
8. Remove the left-hand belt cover No. 2.
9. Remove the tensioner bracket.
10. Remove the oil level gauge guide (LH side only)
11. Remove the spark plug cord.
12. Remove the rocker cover and gasket.
13. Loosen the intake camshaft cap bolts equally, a little at a time in alphabetical sequence shown in the figure.
14. Remove the camshaft caps and intake camshaft.
15. Loosen the exhaust camshaft cap bolts equally, a little at a time in alphabetical sequence shown in the figure.
16. Remove the camshaft caps and exhaust camshaft. CAUTION: Arrange camshaft caps in order so that they can be installed in their original positions.
17. Similarly, remove the right-hand camshafts and related parts.

Scheme 628

Scheme 629

Scheme 630

Scheme 631

Scheme 632

Scheme 633

Scheme 634

Scheme 635

Scheme 636

1. Camshaft installation: Apply engine oil to the cylinder head at camshaft bearing location before installing the camshaft. Install the camshaft so that each valves is close to or in contact with "base circle" of cam lobe. CAUTION: When the camshafts are positioned as shown in the figure, camshafts need to be rotated at a minimum to align with the timing belt during installation. Right-hand camshaft need not be rotated when set at the position shown in the figure. Left-hand intake camshaft: Rotate 80° clockwise. Left-hand exhaust camshaft: Rotate 45° counterclockwise.
2. Camshaft cap installation: Apply fluid packing sparingly to the cap mating surface. CAUTION: Do not apply fluid packing excessively. Failure to do so may cause excess packing to come out and flow toward oil seal, resulting in oil leaks. Fluid packing: THREE BOND 1215 (Part No. 004403007) or equivalent Apply engine oil to cap bearing surface and install the cap on camshaft as shown by identification mark (A). Gradually tighten the cap in at least two stages in alphabetical sequence shown in the figure, and then tighten to specified torque. Tightening torque: T1: 10 N.m (1.0 kgf-m, 7.2 ft-lb) T2: 20 N.m (2.0 kgf-m, 14.5 ft-lb) Similarly, tighten the cap on exhaust side. After tightening the cap, ensure the camshaft rotates only slightly while holding it at "base" circle. Tightening torque: T1: 10 N.m (1.0 kgf-m, 7.2 ft-lb) T2: 20 N.m (2.0 kgf-m, 14.5 ft-lb)
3. Camshaft oil seal installation: Apply grease to the new oil seal lips and press onto the front end of camshaft by using ST1 and ST2. CAUTION: Use a new oil seal. ST1 499587600 OIL SEAL INSTALLER ST2 499597200 OIL SEAL GUIDE
4. Rocker cover installation: Install the gasket on rocker cover. Install the peripheral gasket and ignition coil gasket. Apply fluid packing to four front open edges of peripheral gasket. Fluid packing: THREE BOND 1215 (Part No. 004403007) or equivalent Install the rocker cover on cylinder head. Ensure the gasket is properly positioned during installation.
5. Install the spark plug cord.
6. Similarly, install the parts on right-hand side.
7. Install the right-hand belt cover No. 2. Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb)
8. Install the tensioner bracket. Tightening torque: 25 N.m (2.5 kgf-m, 18.1 ft-lb)
9. Install the left-hand belt cover No. 2. Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb)
10. Install the crankshaft sprocket, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Sprocket.
11. Install the camshaft sprockets, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft Sprocket.
12. Install the timing belt assembly, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
13. Install the belt cover, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
14. Install the crankshaft pulley, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
15. Install the V-belt, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-belt.

Scheme 637

Scheme 638

Scheme 639

Scheme 640

Scheme 641

Scheme 642

1. Measure the bend, and repair or replace if necessary. Limit: 0.020 mm (0.0008 in)
2. Check the journal for damage and wear. Replace if faulty.
3. Measure the outside diameter of camshaft journal. If the journal diameter is not as specified, check the oil clearance.
4. Measurement of the camshaft journal oil clearance: Clean the bearing caps and camshaft journals. Place the camshafts on the cylinder head (Without installing the valve rocker) Place a plastigage across each of the camshaft journals. Gradually tighten the cap in at least two stages in alphabetical sequence shown in the figure, and then tighten to specified torque. Tightening torque: T1: 10 N.m (1.0 kgf-m, 7.2 ft-lb) T2: 20 N.m (2.0 kgf-m, 14.5 ft-lb) CAUTION: Do not turn the camshaft. Remove the bearing caps. Measure the widest point of the plastigage on each journal. If the oil clearance exceeds the limit, replace the camshaft. If necessary, replace the camshaft caps and cylinder head as a set. Standard: 0.037-0.072 mm (0.0015-0.0028 in) Limit: 0.10 mm (0.0039 in) Completely remove the plastigage.
5. Check the cam face condition; remove the minor faults by grinding with oil stone. Measure the cam height H; replace if the limit has been exceeded. Cam height: H Standard: Intake; 46.25-46.35 mm (1.821-1.825 in) Exhaust; 46.15-46.25 mm (1.817-1.821 in) Limit: Intake; 46.15 mm (1.817 in) Exhaust; 46.05 mm (1.813 in) Cam base circle diameter A: 37.0 mm (1.457 in)
6. Measure the thrust clearance of camshaft with dial gauge. If the clearance exceeds the limit, replace the caps and cylinder head as a set. If necessary replace the camshaft. Standard: 0.015-0.070 mm (0.0006-0.0028 in) Limit: 0.1 mm (0.004 in)

Scheme 643

Scheme 644

1. Remove the V-belt, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-Belt.
2. Remove the crankshaft pulley, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
3. Remove the belt cover, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
4. Remove the timing belt assembly, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
5. Remove the camshaft sprocket, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft Sprocket.
6. Remove the intake manifold, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#air-intake-system-h4dotc) , Intake Manifold.
7. Remove the bolt which installs the A/C compressor bracket on cylinder head.
8. Remove the camshaft, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft.
9. Remove the cylinder head bolts in alphabetical sequence shown in the figure. CAUTION: Leave bolts (A) and (D) engaged by three or four threads to prevent the cylinder head from falling.
10. While tapping the cylinder head with a plastic hammer, separate it from cylinder block. CAUTION: Remove the bolts (A) and (D) to remove the cylinder head.
11. Remove the cylinder head gasket. CAUTION: Do not scratch the mating surface of cylinder head and cylinder block.
12. Similarly, remove the right side cylinder head.

Scheme 645

Scheme 646

1. Install the cylinder head and gaskets on cylinder block. CAUTION: Use new cylinder head gaskets. Be careful not to scratch the mating surface of cylinder head and cylinder block.
2. Tighten the cylinder head bolts. Apply a coat of engine oil to washers and bolt threads. Tighten all bolts to 29 N.m (3.0 kgf-m, 22 ft-lb) in alphabetical sequence. Retighten all bolts to 69 N.m (7.0 kgf-m, 51 ft-lb) in alphabetical sequence. Back off all bolts by 180° first, then back them off a further 180°, in the reverse sequence they were tightened. Tighten all bolts to 39 N.m (4.0 kgf-m, 29 ft-lb) in alphabetical sequence. Tighten all bolts 80-90° in alphabetical sequence. Tighten all bolts a further 40-45° in alphabetical sequence. NOTE: Do not tighten bolts for more than 45°. Tighten bolt (A) and (B) a further 40-45°. NOTE: Make sure the sum of retightening angles in previous steps has not exceeded 90°.
3. Install the camshaft, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft.
4. Install the A/C compressor bracket on cylinder head.
5. Install the intake manifold, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#air-intake-system-h4dotc) , Intake Manifold.
6. Install the timing belt assembly, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
7. Install the belt cover, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
8. Install the crankshaft pulley, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
9. Install the V-belt, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-belt.

Scheme 647

1. Remove the valve shims and valve lifters.
2. Compress the valve spring and remove the valve spring retainer key. Remove each valve and valve spring. ST1 498267600 CYLINDER HEAD TABLE ST2 499718000 VALVE SPRING REMOVER CAUTION: Keep the removed parts in order for re-installing in their original positions. Mark each valve to prevent confusion. Use extreme care not to damage the lips of the intake valve oil seals and exhaust valve oil seals.

Scheme 648

Scheme 649

1. Installation of valve spring and valve: Coat the stem of each valve with engine oil and insert the valve into valve guide. CAUTION: When inserting the valve into valve guide, use special care not to damage the oil seal lip. Set the cylinder head on ST1. Install the valve spring and retainer using ST2. ST1 498267600 CYLINDER HEAD TABLE ST2 499718000 VALVE SPRING REMOVER CAUTION: Be sure to install the valve springs with their close-coiled end facing the seat on the cylinder head. Compress the valve spring and fit the valve spring retainer key. After installing, tap the valve spring retainers lightly with wooden hammer for better seating.
2. Apply oil to the surface of the valve lifter and valve shim.
3. Install the valve lifter and valve shim.

Scheme 650

1. Make sure that no crack or other damage exists. In addition to visual inspection, inspect the important areas by means of red check.
2. Measure the warping of the cylinder head surface that mates with crankcase by using a straight edge (A) and thickness gauge (B). If the warping exceeds 0.05 mm (0.0020 in), regrind the surface with a surface grinder. Warping limit: 0.05 mm (0.0020 in) Grinding limit: 0.3 mm (0.012 in) Standard height of cylinder head: 127.5 mm (5.02 in) CAUTION: Uneven torque for the cylinder head nuts can cause warping. When reassembling, pay special attention to the torque so as to tighten evenly.

VALVE SEAT

Inspect the intake and exhaust valve seats, and correct the contact surfaces with valve seat cutter if they are defective or when valve guides are replaced.

Valve seat width: W

1. Intake: Standard; 1.0 mm (0.039 in) Limit; 1.7 mm (0.067 in)
2. Exhaust: Standard; 1.5 mm (0.059 in) Limit; 2.2 mm (0.087 in)

Scheme 651

Scheme 652

Scheme 653

Scheme 654

1. Check the clearance between valve guide and stem. The clearance can be checked by measuring the outside diameter of valve stem and the inside diameter of valve guide with outside and inside micrometers respectively. Clearance between the valve guide and valve stem: Standard: Intake; 0.030-0.057 mm (0.0012-0.0022 in) Exhaust; 0.040-0.067 mm (0.0016-0.0026 in) Limit; 0.15 mm (0.0059 in)
2. If the clearance between valve guide and stem exceeds the limit, replace the valve guide or valve itself whichever shows greater amount of wear. See the following procedure for valve guide replacement. Valve guide inner diameter: 6.000-6.012 mm (0.2362-0.2367 in) Valve stem outer diameters: Intake; 5.955-5.970 mm (0.2362-0.2367 in) Exhaust; 5.945-5.960 mm (0.2341-0.2346 in) Place the cylinder head on ST1 with the combustion chamber upward so that valve guides enter the holes in ST1. Insert the ST2 into valve guide and press it down to remove the valve guide. ST1 498267600 CYLINDER HEAD TABLE ST2 499767200 VALVE GUIDE REMOVER
3. Turn the cylinder head upside down and place ST as shown in the figure. ST 18251AA020 VALVE GUIDE ADJUSTER
4. Before installing a new valve guide, make sure that neither scratches nor damages exist on the inside surface of the valve guide holes in cylinder head.
5. Put a new valve guide, coated with sufficient oil, in cylinder, and insert ST1 into valve guide. Press in until the valve guide upper end is flush with the upper surface of ST2. ST1 499767200 VALVE GUIDE REMOVER ST2 18251AA020 VALVE GUIDE ADJUSTER
6. Check the valve guide protrusion. Valve guide protrusion: L L: 15.8-16.2 mm (0.622-0.638 in)
7. Ream the inside of valve guide with ST. Gently rotate the reamer clockwise while pressing it lightly into the valve guide, and return it also rotating clockwise. After reaming, clean the valve guide to remove chips. ST 499767400 VALVE GUIDE REAMER CAUTION: Apply engine oil to the reamer when reaming. If the inner surface of the valve guide is torn, the edge of the reamer should be slightly ground with an oil stone. If the inner surface of the valve guide becomes lustrous and the reamer does not chips, use a new reamer or remedy the reamer.
8. Recheck the contact condition between valve and valve seat after replacing the valve guide.

Scheme 655

1. Inspect the flange and stem of valve, and replace if damaged, worn, or deformed, or if "H" is less than the specified limit. H: Intake: Standard; 1.2 mm (0.047 in) Limit; 0.8 mm (0.031 in) Exhaust: Standard; 1.5 mm (0.059 in) Limit; 0.8 mm (0.031 in) Valve overall length: Intake; 104.4 mm (4.110 in) Exhaust; 104.7 mm (4.122 in)
2. Put a small amount of grinding compound on the seat surface and lap the valve and seat surface. Install a new intake valve oil seal after lapping.

Scheme 656

Scheme 657

1. Check the valve springs for damage, free length, and tension. Replace the valve spring if it is not within specifications presented in the table.
2. To measure the squareness of the valve spring, stand the spring on a surface plate and measure its deflection at the top using a try square.

INTAKE AND EXHAUST VALVE OIL SEAL

Replace the oil seal with a new one, if the lip is damaged or spring out of place, or when the surfaces of intake valve and valve seat are reconditioned or intake valve guide is replaced.

Scheme 658

1. Place the cylinder head on ST1.
2. Press in the oil seal to the specified dimension indicated in the figure by using ST2. ST1 498267600 CYLINDER HEAD TABLE ST2 498857100 VALVE GUIDE REMOVER CAUTION: Apply engine oil to oil seal before force-fitting. Differentiate between the intake valve oil seal and exhaust valve oil seal by noting their difference in color. Color of rubber part: Intake [Black] Exhaust [Brown] Color of spring part: Intake [Silver] Exhaust [Silver]

Scheme 659

Scheme 660

1. Check the valve lifter visually.
2. Measure the outer diameter of valve lifter. Outer diameter: 34.959-34.975 mm (1.3763-1.3770 in)
3. Measure the inner diameter of valve lifter mating part on cylinder head. Inner diameter: 34.994-35.016 mm (1.3777-1.3786 in) CAUTION: If difference between outer diameter of valve lifter and inner diameter of valve lifter mating part is over the limit, replace the cylinder head. Standard: 0.019-0.057 mm (0.0007-0.0022 in) Limit: 0.100 mm (0.0039 in)

Note. Before conducting this procedure, drain the engine oil completely if applicable.

Scheme 661

Scheme 662

Scheme 663

Scheme 664

Scheme 665

Scheme 666

Scheme 667

Scheme 668

Scheme 669

1. Remove the intake manifold, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#air-intake-system-h4dotc) , Intake Manifold.
2. Remove the V-belt, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-Belt.
3. Remove the crankshaft pulley, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
4. Remove the belt cover, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
5. Remove the timing belt assembly, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
6. Remove the camshaft sprocket, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft Sprocket.
7. Remove the crankshaft sprocket, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Sprocket.
8. Remove the generator and A/C compressor with their brackets.
9. Remove the cylinder head assembly, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Cylinder Head Assembly.
10. Remove the clutch disc and cover (MT vehicles). See «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/clutches-manual-hydraulic/#clutch-system__removal) , Clutch Disc and Cover.
11. Remove the flywheel (MT vehicles). See «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/clutches-manual-hydraulic/#clutch-system) , Flywheel.
12. Remove the drive plate (AT vehicles). Using the ST, lock crankshaft. ST 498497100 CRANKSHAFT STOPPER
13. Remove the oil separator cover.
14. Remove the water by-pass pipe for heater.
15. Remove the oil filter.
16. Remove the oil cooler.
17. Removal of oil pan: Turn the cylinder block with No. 2 and No. 4 piston sides facing upward. Remove the bolts which secure oil pan to cylinder block. Insert a 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.
18. Remove the oil strainer stay.
19. Remove the oil strainer.
20. Remove the baffle plate.
21. Remove the water pipes.
22. Remove the water pump.
23. Remove the oil pump from cylinder block. Use a flat-bladed screwdriver as shown in the figure when removing the oil pump. CAUTION: Be careful not to scratch the mating surface of cylinder block and oil pump.
24. Remove the service hole cover and service hole plugs using the hexagon wrench [14 mm (0.55 in)].
25. Rotate the crankshaft to bring No. 1 and No. 2 pistons to bottom dead center position, then remove the piston circlip through service hole of No. 1 and No. 2 cylinders.
26. Draw out the piston pin from No. 1 and No. 2 pistons using ST. ST 499097600 PISTON PIN REMOVER CAUTION: Be careful not to confuse the original combination of piston, piston pin and cylinder.
27. Similarly remove the piston pins from No. 3 and No. 4 pistons.
28. Remove the bolts which connect cylinder block on the side of No. 2 and No. 4 cylinders.
29. Back off the bolts which connect cylinder block on the side of No. 1 and No. 3 cylinders two or three turns.
30. Set up the cylinder block so that No. 1 and No. 3 cylinders are on the upper side, then remove the cylinder block connecting bolts.
31. Separate the left-hand and right-hand cylinder blocks. CAUTION: When separating the cylinder block, do not allow the connecting rod to fall and damage the cylinder block.
32. Remove the rear oil seal.
33. Remove the crankshaft together with connecting rod.
34. Remove the crankshaft bearings from cylinder block using a hammer handle. CAUTION: Do not confuse the combination of crankshaft bearings. Press the bearing at the end opposite to locking lip.
35. Draw out each piston from cylinder block using a wooden bar or hammer handle. CAUTION: Do not confuse the combination of piston and cylinder.

Scheme 670

Scheme 671

Scheme 672

Scheme 673

Scheme 674

Scheme 675

Scheme 676

Scheme 677

Scheme 678

Scheme 679

Scheme 680

Scheme 681

Scheme 682

Scheme 683

Scheme 684

Scheme 685

Scheme 686

Scheme 687

Scheme 688

Scheme 689

Scheme 690

Scheme 691

Scheme 692

Scheme 693

Scheme 694

Scheme 695

Scheme 696

Scheme 697

Scheme 698

Scheme 699

Scheme 700

1. Position the crankshaft on the No. 2 and No. 4 cylinder block.
2. Apply fluid packing to the mating surface of No. 1 and No. 3 cylinder block, and position it on No. 2 and No. 4 cylinder block. Fluid packing: THREE BOND 1215 (Part No. 004403007) or equivalent CAUTION: Do not allow fluid packing to jut into O-ring grooves, oil passages, bearing grooves, etc.
3. Tighten the 10 mm cylinder block connecting bolts in alphabetical sequence shown in the figure (LH side). Tightening torque: 15 N.m (1.5 kgf-m, 10.8 ft-lb)
4. Tighten the 10 mm cylinder block connecting bolts in alphabetical sequence shown in the figure (RH side). Tightening torque: 15 N.m (1.5 kgf-m, 10.8 ft-lb)
5. Tighten LH side bolts (A)-(D) for a further 90° in alphabetical order.
6. Tighten RH side bolts (E)-(J) for a further 90° in alphabetical order.
7. Tighten the 8 mm and 6 mm cylinder block connecting bolts in alphabetical sequence shown in the figure. Tightening torque: (A)-(G): 25 N.m (2.5 kgf-m, 18.1 ft-lb) (H): 6.4 N.m (0.65 kgf-m, 4.7 ft-lb)
8. Install the rear oil seal using ST1 and ST2. ST1 499597100 OIL SEAL GUIDE ST2 499587200 OIL SEAL INSTALLER
9. Position the top ring gap at (A) or (B) in the figure.
10. Position the second ring gap at 180° apart from the top ring gap.
11. Position the expander gap at (C) in the figure.
12. Position the lower rail gap at (D) in the figure.
13. Align the lower rail rotation stopper (F) with the hole (E) in the side of piston.
14. Position the upper rail gap at (G) in the figure. NOTE: Ensure the ring gaps do not face the same direction. Ensure ring gaps are not within the piston skirt area.
15. Installing the circlip: Install the circlips in piston holes located opposite of the service holes in cylinder block, when positioning all pistons in the corresponding cylinders. NOTE: Use new circlips. CAUTION: Piston front mark faces towards the front of the engine.
16. Installing the piston: Turn the cylinder block so that No. 1 and No. 2 cylinders face upward. Using ST1, turn the crankshaft so that No. 1 and No. 2 connecting rods are set at bottom dead center. ST1 499987500 CRANKSHAFT SOCKET Apply a coat of engine oil to the pistons and cylinders and insert pistons in their cylinders using ST2. ST2 398744300 PISTON GUIDE
17. Installing piston pin: Insert ST3 into service hole to align piston pin hole with connecting rod small end. CAUTION: Apply a coat of engine oil to ST3 before insertion. ST3 499017100 PISTON PIN GUIDE Apply a coat of engine oil to the piston pin and insert piston pin into piston and connecting rod through service hole. Install the circlip using ST. ST 499897200 PISTON SNAP RING PLIERS CAUTION: Use new circlips. Apply fluid packing around the service hole plug. Fluid packing: THREE BOND 1215 (Part No. 004403007) or equivalent Install the service hole plug and gasket. CAUTION: Use a new gasket. Turn the cylinder block so that No. 3 and No. 4 cylinders face upward. Using the same procedures as used for No. 1 and No. 2 cylinders, install the pistons and piston pins.
18. Install the water pipe.
19. Install the baffle plate. Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb)
20. Install the oil strainer and O-ring Tightening torque: 10 N.m (1.0 kgf-m, 7 ft-lb)
21. Install the oil strainer stay.
22. Apply fluid packing to matching surfaces and install the oil pan. Fluid packing: THREE BOND 1215 (Part No. 004403007) or equivalent
23. Apply fluid packing to matching surfaces and install the oil separator cover. Fluid packing: THREE BOND 1215 (Part No. 004403007) or equivalent
24. Install the drive plate (AT vehicles) To lock the crankshaft, use ST. ST 498497100 CRANKSHAFT STOPPER Tightening torque: 72 N.m (7.3 kgf-m, 52.8 ft-lb)
25. Install the flywheel (MT vehicles), see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/clutches-manual-hydraulic/#clutch-system) , Flywheel.
26. Install the clutch disc and cover (MT vehicles), see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/clutches-manual-hydraulic/#clutch-system__installation) , Clutch Disc and Cover.
27. Installation of oil pump: Discard the front oil seal after removal. Replace with a new one using ST. ST 499587100 OIL SEAL INSTALLER Apply fluid packing to the matching surface of oil pump. Fluid packing: THREE BOND 1215 (Part No. 004403007) or equivalent Apply a coat of engine oil to the inside of the oil seal. Install the oil pump on cylinder block. Be careful not to damage the oil seal during installation. Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) CAUTION: Do not forget to install the O-ring and seal when installing the oil pump. Align the flat surface of oil pump's inner rotor with crankshaft before installation.
28. Install the water pump and gasket. Tightening torque: First; 12 N.m (1.2 kgf-m, 8.7 ft-lb) Second; 12 N.m (1.2 kgf-m, 8.7 ft-lb) CAUTION: Be sure to use a new gasket. When installing the water pump, tighten bolts in two stages in alphabetical sequence as shown in the figure.
29. Install the water by-pass pipe for heater.
30. Install the oil cooler. Tightening torque: T1: 55 N.m (5.5 kgf-m, 40 ft-lb) T2: 70 N.m (7.0 kgf-m, 50.6 ft-lb) T3: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb)
31. Install the oil filter using ST. ST 498547000 OIL FILTER WRENCH
32. Install the water by-pass pipe between oil cooler and water pump.
33. Install the water pipe. NOTE: Always use a new O-ring.
34. Install the cylinder head assembly, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Cylinder Head Assembly.
35. Install the oil level gauge guide and tighten the attaching bolt (left side only).
36. Install the rocker cover.
37. Install the crankshaft sprocket, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Sprocket.
38. Install the camshaft sprockets, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Camshaft Sprocket.
39. Install the timing belt assembly, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Timing Belt Assembly.
40. Install the belt cover, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Belt Cover.
41. Install the crankshaft pulley, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , Crankshaft Pulley.
42. Install the generator and A/C compressor brackets on cylinder head.
43. Install the V-belt, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , V-belt.
44. Install the intake manifold, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#air-intake-system-h4dotc) , Intake Manifold.

Scheme 701

1. Remove the connecting rod cap.
2. Remove the connecting rod bearing. CAUTION: Arrange the removed connecting rod, connecting rod cap and bearing in order to prevent confusion.
3. Remove the piston rings using the piston ring expander.
4. Remove the oil ring by hand. CAUTION: Arrange the removed piston rings in proper order to prevent confusion.
5. Remove the circlip.

Scheme 702

1. Install the connecting rod bearings on connecting rods and connecting rod caps. CAUTION: Apply oil to the surfaces of the connecting rod bearings.
2. Install the connecting rod on crankshaft. CAUTION: Position each connecting rod with the side marked facing forward.
3. Install the connecting rod cap with connecting rod nut. Ensure the arrow on connecting rod cap faces the front during installation. CAUTION: Each the connecting rod has its own mating cap. Make sure that they are assembled correctly by checking their matching number. When tightening the connecting rod nuts, apply oil on the threads.
4. Install the oil ring spacer, upper rail and lower rail in this order by hand. Then install the second ring and top ring with a piston ring expander.

CYLINDER BLOCK

1. Visually check for cracks and damage. Especially, inspect the important parts by means of red lead check.
2. Check the oil passages for clogging.
3. Inspect the crankcase surface that mates with cylinder head for warping by using a straight edge, and correct by grinding if necessary. Warping limit: 0.05 mm (0.0020 in) Grinding limit: 0.1 mm (0.004 in) Standard height of cylinder block: 201.0 mm (7.91 in)

Scheme 703

Scheme 704

Scheme 705

1. The cylinder bore size is stamped on the cylinder block's front upper surface. CAUTION: Measurement should be performed at a temperature of 20°C (68°F). NOTE: Standard sized pistons are classified into two grades, "A" and "B". These grades should be used as a guide line in selecting a standard piston. Standard diameter: A: 92.005-92.015 mm (3.6222-3.6226 in) B: 91.995-92.005 mm (3.6218-3.6222 in)
2. How to measure the inner diameter of each cylinder: Measure the inner diameter of each cylinder in both the thrust and piston pin directions at the heights shown in the figure, using a cylinder bore gauge. CAUTION: Measurement should be performed at a temperature of 20°C (68°F). Taper: Standard; 0.015 mm (0.0006 in) Limit; 0.050 mm (0.0020 in) Out-of-roundness: Standard; 0.010 mm (0.0004 in) Limit; 0.050 mm (0.0020 in)
3. When the piston is to be replaced due to general or cylinder wear, determine a suitable sized piston by measuring the piston clearance.
4. How to measure the outer diameter of each piston: Measure the outer diameter of each piston at the height shown in the figure (thrust direction) CAUTION: Measurement should be performed at a temperature of 20°C (68°F). Piston grade point H: 38.7 mm (1.524 in) Piston outer diameter: Standard: A: 91.985-91.995 mm (3.6214-3.6218 in) B: 91.975-91.985 mm (3.6211-3.6214 in) 0.25 mm (0.0098 in) Oversize: 92.225-92.235 mm (3.6309-3.6313 in) 0.50 mm (0.0197 in) Oversize: 92.475-92.485 mm (3.6407-3.6411 in)
5. Calculate the clearance between cylinder and piston. CAUTION: Measurement should be performed at a temperature of 20°C (68°F). Cylinder to piston clearance at 20°C (68°F): Standard; 0.010-0.030 mm (0.0004-0.0012 in) Limit; 0.050 mm (0.0020 in)
6. Boring and honing: If the value of taper, out-of-roundness, or cylinder-to-piston clearance measured exceeds the specified limit or if there is any damage on the cylinder wall, rebore it to use an oversize piston. CAUTION: When any of the cylinders needs reboring, all other cylinders must be bored at the same time, and use oversize pistons. Do not perform boring on one cylinder only, nor use an oversize piston for one cylinder only. If the cylinder inner diameter exceeds the limit after boring and honing, replace the crankcase. CAUTION: Immediately after reboring, the cylinder diameter may differ from its real diameter due to temperature rise. Thus, pay attention to this when measuring the cylinder diameter. Limit of cylinder enlarging (boring): 0.5 mm (0.020 in)

Scheme 706

Scheme 707

Scheme 708

1. Check the pistons and piston pins for damage, cracks, and wear and the piston ring grooves for wear and damage. Replace if defective.
2. Measure the piston-to-cylinder clearance at each cylinder. See «CYLINDER AND PISTON»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) , INSPECTION, Cylinder Block.
3. Make sure that the piston pin can be inserted into the piston pin hole with a thumb at 20°C (68°F). Replace if defective. Standard clearance between piston pin and hole in piston: Standard; 0.004-0.008 mm (0.0002-0.0003 in) Limit; 0.020 mm (0.0008 in)
4. Check the circlip installation groove on the piston for burr (A). If necessary, remove burr from the groove so that the piston pin can lightly move.
5. Check the piston pin circlip for distortion, cracks and wear.

Scheme 709

Scheme 710

Scheme 711

Scheme 712

Scheme 713

1. If the piston ring is broken, damaged, or worn, or if its tension is insufficient, or when the piston is replaced, replace the piston ring with a new one of the same size as the piston. NOTE: The mark is indicated on the end of the top ring and second ring. When installing the rings to the piston, face this mark upward. The oil ring consists of an upper rail, expander and a lower rail. When installing to the piston, be careful to face the rails to the correct direction.
2. Squarely place the piston ring and oil ring in cylinder, and measure the piston ring gap with a thickness gauge.
3. Measure the clearance between piston ring and piston ring groove with a thickness gauge. CAUTION: Before measuring the clearance, clean the piston ring groove and piston ring.

Scheme 714

Scheme 715

Scheme 716

Scheme 717

Scheme 718

1. Replace the connecting rod, if the large or small end thrust surface is damaged.
2. Check for bend or twist using a connecting rod aligner. Replace the connecting rod if the bend or twist exceeds the limit. Limit of bend or twist per 100 mm (3.94 in) in length: 0.10 mm (0.0039 in)
3. Install the connecting rod fitted with bearing to crankshaft and measure the side clearance (thrust clearance). Replace the connecting rod if the side clearance exceeds the specified limit. Connecting rod side clearance: Standard; 0.070-0.330 mm (0.0028-0.0130 in) Limit; 0.4 mm (0.016 in)
4. Inspect the connecting rod bearing for scar, peeling, seizure, melting, wear, etc.
5. Measure the oil clearance on individual connecting rod bearings by means of plastigage. If any oil clearance is not within specification, replace the defective bearing with a new one of standard size or undersize as necessary, see «Connecting Rod Bearing Specifications»(/subaru/impreza-wrx/gdgg-2002-2005/remont/mechanical/#engine-mechanical-20l-dohctc) table. Connecting rod oil clearance: Standard; 0.020-0.046 mm (0.0008-0.0018 in) Limit; 0.05 mm (0.0020 in) CONNECTING ROD BEARING SPECIFICATIONS Application Unit: mm (in) Unit: mm (in) Bearing Bearing size (Thickness at center) Outer diameter of crank pin Standard 1.486-1.498 (0.0585-0.0590) 51.984-52.000 (2.0466-2.0472) 0.03 (0.0012) undersize 1.504-1.512 (0.0592-0.0596) 51.954-51.970 (2.0454-2.0461) 0.05 (0.0020) undersize 1.514-1.522 (0.0596-0.0599) 51.934-51.950 (2.0447-2.0453) 0.25 (0.0098) undersize 1.614-1.622 (0.0635-0.0639) 51.734-51.750 (2.0368-2.0374)
6. Inspect the bushing at connecting rod small end, and replace if worn or damaged. Also measure the piston pin clearance at the connecting rod small end. Clearance between piston pin and bushing: Standard; 0-0.022 mm (0-0.0009 in) Limit; 0.030 mm (0.0012 in)
7. Replacement procedure is as follows: Remove the bushing from connecting rod with ST and press. Press the bushing with ST after applying oil on the periphery of bushing. ST 499037100 CONNECTING ROD BUSHING REMOVER AND INSTALLER Make two 3 mm (0.12 in) holes in bushing. Ream the inside of bushing. After completion of reaming, clean the bushing to remove chips.

Scheme 719

Scheme 720

Scheme 721

Scheme 722

Scheme 723

1. Clean the crankshaft completely and check for cracks by means of red lead check etc., and replace if defective.
2. Measure the crankshaft bend, and correct or replace if it exceeds the limit. CAUTION: If a suitable V-block is not available, install No. 1 and No. 5 crankshaft bearing on cylinder block, position crankshaft on these bearings and measure the crankshaft bend using a dial gauge. Crankshaft bend limit: 0.035 mm (0.0014 in)
3. Inspect the crank journal and crank pin for wear. If they are not within the specifications, replace the bearing with a suitable (undersize) one, and replace or recondition crankshaft as necessary. When grinding the crank journal or crank pin, finish them to the specified dimensions according to the undersize bearing to be used. Crank pin and crank journal: Out-of-roundness; 0.020 mm (0.0008 in) or less Taper limit; 0.07 mm (0.0028 in) Grinding limit; 0.250 mm (0.0098 in)
4. Measure the thrust clearance of crankshaft at center bearing. If the clearance exceeds the limit, replace the bearing. Crankshaft thrust clearance: Standard; 0.030-0.115 mm (0.0012-0.0045 in) Limit; 0.25 mm (0.0098 in)
5. Inspect individual crankshaft bearings for signs of flaking, seizure, melting, and wear.
6. Measure the oil clearance on each crankshaft bearing by means of plastigage. If the measurement is not within the specification, replace the defective bearing with an undersize one, and replace or recondition the crankshaft as necessary.

Note. "RANK" shown in the chart refers to the possibility of reason for the trouble in order ("Very often" to "Rarely")

A -Very often

B -Sometimes

C -Rarely

Scheme 724

Scheme 725

Scheme 726

Scheme 727

Scheme 728

Note. When disconnecting fuel injector connector, CHECK ENGINE malfunction indicator light illuminates and a diagnostic trouble code is stored in the ECM memory. See DIAGNOSTIC TROUBLE CODE DEFINITIONS , Engine Performance. Therefore, carry out the CLEAR MEMORY MODE after connecting the fuel injector connector. See CLEARING DIAGNOSTIC TROUBLE CODES , Engine Performance.

Scheme 729

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

Scheme 730

Scheme 731

Scheme 732

Scheme 733

Scheme 734

Scheme 735

See also:
• RELEASING OF FUEL PRESSURE
• REMOVAL
• IDLE SPEED
• IGNITION TIMING
• REMOVAL
• REMOVAL
• REMOVAL
• REMOVAL
• REMOVAL
• INSTALLATION
• REFRIGERANT CHARGING PROCEDURE
• REMOVAL
• A/C COMPRESSOR, ALTERNATOR & POWER STEERING BELT
• REMOVAL & INSTALLATION (IMPREZA WRX 2.0L)
• REMOVAL
• REMOVAL
• INSTALLATION
• DIAGNOSTIC TROUBLE CODE DEFINITIONS
• CLEARING DIAGNOSTIC TROUBLE CODES
• ADJUSTMENT
• INSPECTION
• FRONT SIDE BELT