Engine Mechanical (h4dotc) Subaru Impreza WRX GD/GG рестайлинг 2

SPECIFICATIONS

GENERAL SPECIFICATIONS

BELT TENSION ADJUSTER REFERENCE

Exploded View Of Timing Belt Components With Torque Specifications. Scheme 274

Exploded View Of Cylinder Head And Camshaft Components With Torque Specifications. Scheme 275

Exploded View Of Cylinder Head And Valve Assembly Components. Scheme 276

Exploded View Of Cylinder Block Components With Torque Specifications. Scheme 277

Exploded View Of Crankshaft And Piston Components With Torque Specifications. Scheme 278

Identifying Engine Mounting Components With Torque Specifications. Scheme 279

CAUTION

1. Wear work 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 and 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 yourself, 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 rigid racks at the specified points.
8. Before disconnecting electrical connectors of sensors or units, be sure to disconnect the ground cable 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 reinstalled 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.

SPECIAL TOOL

SPECIAL TOOL ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS 498267600 CYLINDER HEAD TABLE Used for replacing valve guides. Used for removing and installing valve springs. 498457000 ENGINE STAND ADAPTER RH Used with ENGINE STAND (499817100). 498457100 ENGINE STAND ADAPTER LH Used with ENGINE STAND (499817100). 498497100 CRANKSHAFT STOPPER Used for stopping rotation of flywheel when loosening and tightening crank pulley bolt, etc. 498747300 PISTON GUIDE Used for installing piston in cylinder. 498857100 VALVE OIL SEAL GUIDE Used for press-fitting of intake and exhaust valve guide oil seals. 499017100 PISTON PIN GUIDE Used for installing piston pin, piston and connecting rod. 499037100 CONNECTING ROD BUSHING REMOVER & INSTALLER Used for removing and installing connecting rod bushing. 499097700 PISTON PIN REMOVER ASSY Used for removing piston pin. 499207400 CAM SPROCKET WRENCH Used for removing and installing cam sprocket. (Exhaust side) 499977500 CAM SPROCKET WRENCH Used for removing and installing cam sprocket. (Intake side) 499587200 CRANKSHAFT OIL SEAL INSTALLER Used for installing crankshaft oil seal. Used with CRANKSHAFT OIL SEAL GUIDE (499597100). 499597100 CRANKSHAFT OIL SEAL GUIDE Used for installing crankshaft oil seal. Used with CRANKSHAFT OIL SEAL INSTALLER (499587200). 499718000 VALVE SPRING REMOVER Used for removing and installing valve spring. 18251AA020 VALVE GUIDE ADJUSTER Used for installing intake and exhaust valve guides. 499767200 VALVE GUIDE REMOVER Used for removing valve guides. 499767400 VALVE GUIDE REAMER Used for reaming valve guides. 499817100 ENGINE STAND Stand used for engine disassembly and assembly. Used with ENGINE STAND ADAPTER RH (498457000) & LH (498457100). 499977100 CRANK PULLEY WRENCH Used for stopping rotation of crank pulley when loosening and tightening crank pulley bolts. 499987500 CRANKSHAFT SOCKET Used for rotating crankshaft. 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)) 499587100 OIL SEAL INSTALLER Used for installing oil pump oil seal. 499587600 OIL SEAL GUIDE Used for installing camshaft oil seal for DOHC engine. 499597200 OIL SEAL GUIDE Used for installing camshaft oil seal for DOHC engine. Used with OIL SEAL GUIDE (499587600). 498277200 STOPPER SET Used for installing automatic transmission assembly to engine. 42099AE000 CONNECTOR REMOVER Used for removing quick connector in engine compartment. 18482AA010 (Newly adopted tool) CARTRIDGE Troubleshooting for electrical systems. 22771AA030 SUBARU SELECT MONITOR KIT Troubleshooting for electrical systems

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GENERAL TOOL

GENERAL TOOL

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

Scheme 299

1. After warming-up the engine, turn the ignition switch to OFF.
2. Make sure that the battery is fully charged.
3. Release the fuel pressure. < Ref. to «RELEASING OF FUEL PRESSURE»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#fuel-injection-fuel-systems-h4dotc__releasing-of-fuel-pressure), PROCEDURE, Fuel. >
4. Remove all the spark plugs. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/ignition-system/#ignition-h4dotc-engine__removal), Spark Plug. >
5. Fully open the throttle valve.
6. Check the starter motor for satisfactory performance and operation.
7. Fix the compression gauge securely against spark plug hole. NOTE: The screw of screw-in type compression gauge (put into cylinder head spark plug hole) should be less than 18 mm (0.71 in) long.
8. Crank the engine by means of starter motor, and then read the maximum value on the gauge when the gauge needle is steady. (Scheme 280): Connecting Compression Gauge Into Cylinder Head Spark Plug Hole
9. Perform at least two measurements per cylinder, and make sure that the values are correct. Compression (at 200 - 300 rpm): Standard: 981 - 1,177 kPa (10 - 12 kgf/cm 2, 142 - 171 psi) Difference between cylinders Less than 49 kPa (0.5 kgf/cm 2, 7 psi)

Scheme 300

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 the hoses are connected properly. Ensure the malfunction indicator light does not illuminate.
2. Warm-up the engine.
3. Stop the engine, and then turn the ignition switch to OFF.
4. Insert the cartridge to Subaru Select Monitor.
5. Connect the Subaru Select Monitor to data link connector. (Scheme 281): Locating Data Link Connector
6. Turn the ignition switch to ON, and Subaru Select Monitor power switch to ON.
7. Select the {2. Each System Check} in Main Menu.
8. Select the {Engine Control System} in Selection Menu.
9. Select the {1. Current Data Display & Save} in Engine Control System Diagnosis.
10. Select the {1.12 Data Display} in Data Display Menu.
11. Start the engine, and then read the 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]: 700±100 rpm
13. Check the idle speed when loaded. (Turn the air conditioning switch to "ON" and operate the compressor for at least 1 minute before measurement.) Idle speed [A/C "ON", no load and gears in neutral]: When the A/C refrigerant pressure is low MT: 725±100 rpm AT: 750±100 rpm When the A/C refrigerant pressure is high MT: 800±100 rpm AT: 825±100 rpm NOTE: As idle speed is controlled by the automatic adjustment type, it can not be adjusted manually. If the idle speed is out of specifications, refer to General On-board Diagnosis Table under "Engine Control System". < Ref. to «BASIC DIAGNOSTIC PROCEDURE»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/testing-diagnostics/#engine-controls-engine-diagnostics-h4dotc). >

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 does not illuminate.
2. Warm-up the engine.
3. Stop the engine, and then turn the ignition switch to OFF.
4. Insert the cartridge to Subaru Select Monitor.
5. Connect the Subaru Select Monitor to data link connector. (Scheme 282): Locating Data Link Connector
6. Turn the ignition switch to ON, and Subaru Select Monitor power switch to ON.
7. Select the {2. Each System Check} in Main Menu.
8. Select the {Engine Control System} in Selection Menu.
9. Select the {1. Current Data Display & Save} in Engine Control System Diagnosis.
10. Select the {1.12 Data Display} in Data Display Menu.
11. Start the engine and check the ignition timing at idle speed. Ignition timing [BTDC/rpm]: 17°±10°/700 If the timing is not correct, check the ignition control system. Refer to Engine Control System. < Ref. to «BASIC DIAGNOSTIC PROCEDURE»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/testing-diagnostics/#engine-controls-engine-diagnostics-h4dotc). >

Scheme 301

1. Warm-up the engine.
2. Disconnect the brake vacuum hose from the intake manifold, and then install the vacuum gauge.
3. Keep the engine at the idle speed, and then read the vacuum gauge indication. By observing the gauge needle movement, the internal condition of engine can be diagnosed as described below. (Scheme 283): Identifying Vacuum Gauge Vacuum pressure (at idling, A/C "OFF"): Less than -60.0 kPa (-450 mmHg, -17.72 inHg)

VACUUM PRESSURE SPECIFICATIONS

Scheme 302

1. Remove the oil pressure switch. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/lubrication-system/#lubrication-h4dotc), 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 then measure the oil pressure. (Scheme 284): Connecting Oil Pressure Gauge Hose To Cylinder Block Oil pressure: 98 kPa (1.0 kgf/cm 2, 14 psi) or more at 600 rpm 294 kPa (3.0 kgf/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. < Ref. to «INSPECTION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/lubrication-system/#lubrication-h4dotc), Engine Lubrication System Trouble in General. > If the oil pressure warning light is turned ON and oil pressure is in specification, replace the oil pressure switch. < Ref. to «INSPECTION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/lubrication-system/#lubrication-h4dotc), Engine Lubrication System Trouble in General. > 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. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/lubrication-system/#lubrication-h4dotc), Oil Pressure Switch. > Tightening torque: 25 N.m (2.5 kgf-m, 18.4 ft-lb)

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

Scheme 303

Scheme 304

1. Release the fuel pressure. < Ref. to «RELEASING OF FUEL PRESSURE»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#fuel-injection-fuel-systems-h4dotc__releasing-of-fuel-pressure), PROCEDURE, Fuel. >
2. Disconnect the fuel delivery hoses from fuel damper, and then connect the fuel pressure gauge. (Scheme 285): Connecting Fuel Pressure Gauge
3. Connect the connector of fuel pump relay. (Scheme 286): Locating Fuel Pump Relay Connector
4. Start the engine.
5. Measure the 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)
6. After connecting the pressure regulator vacuum hose, measure the 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.

Inspection and adjustment of the valve clearance should be performed while engine is cold.

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1. Set the vehicle on a lift.
2. Disconnect the ground cable from battery.
3. Remove the air intake duct. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#intake-induction-h4dotc-engine), Air Intake Duct. >
4. Remove the bolts which secure 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), and then remove the timing belt cover.
8. Lower the vehicle.
9. When inspecting the #1 and #3 cylinders: Pull out the engine harness connector with bracket from air cleaner upper cover. (Scheme 287): Identifying Engine Harness Connector Remove the air cleaner case. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#intake-induction-h4dotc-engine), Air Cleaner Case. > Disconnect the ignition coil connector. Remove the ignition coil. Place a suitable container under the vehicle. Disconnect the PCV hose from rocker cover (RH). Remove the bolts, and then remove the rocker cover (RH).
10. When inspecting the #2 and #4 cylinders: Disconnect the battery cable, and then remove the battery and battery carrier. Remove the secondary air pump. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#emission-control-aux-emission-control-devices-h4dotc-engine), Secondary Air Pump. > Disconnect the ignition coil connector. Remove the ignition coil. Place a suitable container under the vehicle. Disconnect the PCV hose from rocker cover (LH). Remove the bolts, and then remove the rocker cover (LH).
11. Turn the crank pulley clockwise until arrow mark on the cam sprocket is set to position shown in the figure. NOTE: Turn the crankshaft using socket wrench. (Scheme 288): Identifying Mark On Cam Sprocket
12. Measure the #1 cylinder intake valve and #3 cylinder exhaust valve clearance by using thickness gauge (A). NOTE: Insert the thickness gauge (A) in as horizontal a direction as possible with respect to the shim. Measure the exhaust valve clearances while lifting-up the vehicle. Valve clearance: STD Intake: 0.20±0.02 mm (0.0079±0.0008 in) Exhaust: 0.35±0.02 mm (0.0138±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. (Scheme 289): Identifying Thickness Gauge
13. If necessary, adjust the valve clearance. < Ref. to «ADJUSTMENT»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc__adjustment), Valve Clearance. >
14. Further turn the crank pulley clockwise. Using the same procedures described previously, and then measure the valve clearances again. Set the arrow mark on cam sprocket to position shown in the figure, and then measure the #2 cylinder exhaust valve and #3 cylinder intake valve clearances. (Scheme 290): Identifying Mark On Cam Sprocket To Position (1 Of 3) Set the arrow mark on cam sprocket to position shown in the figure, and then measure the #2 cylinder intake valve and #4 cylinder exhaust valve clearances. (Scheme 291): Identifying Mark On Cam Sprocket To Position (2 Of 3) Set the arrow mark on cam sprocket to position shown in the figure, and then measure the #1 cylinder exhaust valve and #4 cylinder intake valve clearances. (Scheme 292): Identifying Mark On Cam Sprocket To Position (3 Of 3)
15. After inspection, install the related parts in the reverse order of removal. Tightening torque: 33 N.m (3.4 kgf-m, 25 ft-lb) (Scheme 293): Locating Bolts

ADJUSTMENT

Scheme 312

Scheme 313

1. Measure all valve clearances. < Ref. to «INSPECTION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Valve Clearance. > NOTE: Record each valve clearance after it has been measured. (Scheme 294): Measuring Valve Clearances
2. Remove the camshaft. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Camshaft. >
3. Remove the valve lifter.
4. Measure the thickness of valve lifter with a micrometer. (Scheme 295): Measuring Thickness Of Valve Lifter With Micrometer
5. Select a shim of suitable thickness using measured valve clearance and valve lifter thickness, by referring to the following table. COMPONENTS THICKNESS SPECIFICATIONS Unit: mm Intake valve: S = (V + T) - 0.20 Exhaust valve: S = (V + T) - 0.35 S: Required thickness of valve lifter V: Measured valve clearance T: Used valve lifter thickness COMPONENTS THICKNESS SPECIFICATIONS Part No. Thickness mm (in) 13228 AB102 4.68(0.1843) 13228 AB112 4.69(0.1846) 13228 AB122 4.70(0.1850) 13228 AB132 4.71 (0.1854) 13228 AB142 4.72(0.1858) 13228 AB152 4.73(0.1862) 13228 AB162 4.74(0.1866) 13228 AB172 4.75(0.1870) 13228 AB182 4.76(0.1874) 13228 AB192 4.77(0.1878) 13228 AB202 4.78(0.1882) 13228 AB212 4.79(0.1886) 13228 AB222 4.80(0.1890) 13228 AB232 4.81 (0.1894) 13228 AB242 4.82(0.1898) 13228 AB252 4.83(0.1902) 13228 AB262 4.84(0.1906) 13228 AB272 4.85(0.1909) 13228 AB282 4.86(0.1913) 13228 AB292 4.87(0.1917) 13228 AB302 4.88(0.1921) 13228 AB312 4.89(0.1925) 13228 AB322 4.90(0.1929) 13228 AB332 4.91 (0.1933) 13228 AB342 4.92(0.1937) 13228 AB352 4.93(0.1941) 13228 AB362 4.94(0.1945) 13228 AB372 4.95(0.1949) 13228 AB382 4.96(0.1953) 13228 AB392 4.97(0.1957) 13228 AB402 4.98(0.1961) 13228 AB412 4.99(0.1965) 13228 AB422 5.00(0.1969) 13228 AB432 5.01 (0.1972) 13228 AB442 5.02(0.1976) 13228 AB452 5.03(0.1980) 13228 AB462 5.04(0.1984) 13228 AB472 5.05(0.1988) 13228 AB482 5.06(0.1992) 13228 AB492 5.07(0.1996) 13228 AB502 5.08 (0.2000) 13228 AB512 5.09 (0.2004) 13228 AB522 5.10(0.2008) 13228 AB532 5.11 (0.2012) 13228 AB542 5.12(0.2016) 13228 AB552 5.13(0.2020) 13228 AB562 5.14 (0.2024) 13228 AB572 5.15(0.2028) 13228 AB582 5.16(0.2031) 13228 AB592 5.17(0.2035) 13228 AB602 5.18 (0.2039) 13228 AB612 5.19(0.2043) 13228 AB622 5.20 (0.2047) 13228 AB632 5.21 (0.2051) 13228 AB642 5.22 (0.2055) 13228 AB652 5.23 (0.2059) 13228 AB662 5.24 (0.2063) 13228 AB672 5.25 (0.2067) 13228 AB682 5.26(0.2071) 13228 AB692 5.27 (0.2075) 13228 AB702 4.38(0.1724) 13228 AB712 4.40 (0.1732) 13228 AB722 4.42(0.1740) 13228 AB732 4.44(0.1748) 13228 AB742 4.46(0.1756) 13228 AB752 4.48(0.1764) 13228 AB762 4.50(0.1771) 13228 AB772 4.52(0.1780) 13228 AB782 4.54(0.1787) 13228 AB792 4.56 (0.1795) 13228 AB802 4.58(0.1803) 13228 AB812 4.60(0.1811) 13228 AB822 4.62(0.1819) 13228 AB832 4.64(0.1827) 13228 AB842 4.66(0.1835) 13228 AB852 5.29 (0.2083) 13228 AB862 5.31 (0.2091) 13228 AB872 5.33 (0.2098) 13228 AB882 5.35(0.2106) 13228 AB892 5.37(0.2114) 13228 AB902 5.39(0.2122) 13228 AB912 5.41 (0.2126) 13228 AB922 5.43(0.2138) 13228 AB932 5.45 (0.2146) 13228 AB942 5.47(0.2154) 13228 AB952 5.49(0.2161) 13228 AB962 5.51 (0.2169) 13228 AB972 5.53(0.2177) 13228 AB982 5.55(0.2185) 13228 AB992 5.57(0.2193) 13228 AC002 5.59(0.2201) 13228 AC012 5.61 (0.2209) 13228 AC022 5.63(0.2217) 13228 AC032 5.65 (0.2224)
6. 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.
7. After inspection, install the related parts in the reverse order of removal.

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1. Set the vehicle on a lift.
2. Open the front hood fully, and then support with the hood stay.
3. Collect the refrigerant from A/C system. < Ref. to «REFRIGERANT RECOVERY PROCEDURE»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/general-servicing-all-makes/#hvac-system-heater-ventilator-and-ac). >
4. Release the fuel pressure. < Ref. to «RELEASING OF FUEL PRESSURE»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#fuel-injection-fuel-systems-h4dotc__releasing-of-fuel-pressure), PROCEDURE, Fuel. > Disconnect the fuel pump relay connector. (Scheme 296): Locating Fuel Pump Relay Connector Start the engine, and run until stalls. After the engine stalls, crank it for 5 seconds more. Turn the ignition switch to OFF.
5. Remove the fuel filler cap.
6. Disconnect the ground cable from battery.
7. Remove the radiator from vehicle. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/cooling-fan/#cooling-system-h4dotc), Radiator. >
8. Remove the coolant filler tank. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/cooling-fan/#cooling-system-h4dotc), Coolant Filler Tank. >
9. Remove the secondary air pump. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#emission-control-aux-emission-control-devices-h4dotc-engine), Secondary Air Pump. >
10. Disconnect the A/C pressure hoses from A/C compressor. (Scheme 297): Identifying A/C Pressure Hoses
11. Remove the intercooler. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#intake-induction-h4dotc-engine), Intercooler. >
12. Disconnect the following connectors and cable. Engine harness connector (Scheme 298): Identifying Engine Harness Connector Engine ground terminal (Scheme 299): Identifying Engine Ground Terminal Engine harness connector (Scheme 300): Identifying Engine Harness Connector Generator connector, terminal and A/C compressor connectors see scheme 28: Identifying Generator Connector, Terminal And A/C Compressor Connectors Power steering switch connector (Scheme 301): Locating Power Steering Switch Connector
13. Disconnect the following hoses. Brake booster vacuum hose (Scheme 302): Locating Brake Booster Vacuum Hose Heater inlet and outlet hose
14. Remove the power steering pump. Remove the front side V-belt. < Ref. to «FRONT SIDE BELT»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc__front-side-belt), REMOVAL, V-belt. > Remove the power steering pipe with bracket from fuel pipe protector RH. (Scheme 303): Locating Power Steering Pipe With Bracket Remove the power steering pump. (Scheme 304): Identifying Power Steering Pump Remove the reservoir tank from bracket by pulling it upward. (Scheme 305): Locating Reservoir Tank Place the power steering pump on right side wheel apron. (Scheme 306): Identifying Power Steering Pump
15. Lift-up the vehicle.
16. Remove the ATF cooler pipe from frame. (AT model)
17. Remove the center exhaust pipe. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/exhaust/#exhaust-h4dotc-engine), Center Exhaust Pipe. >
18. Remove the nuts which hold the lower side of transmission to engine. (Scheme 307): Locating Transmission Engine Nut
19. Remove the nuts which install the front cushion rubber onto front crossmember. (Scheme 308): Locating Front Crossmember Nuts
20. Separate the clutch release fork from release bearing. (MT model) < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/clutches-manual-hydraulic/#clutch-system), Release Bearing and Lever. >
21. Separate the torque converter clutch from drive plate. (AT model) Lower the vehicle. Remove the service hole plug. Remove the bolts which hold the torque converter clutch to drive plate. While rotating the crank pulley in the direction of engine rotation little by little using a socket wrench, remove all the bolts. (Scheme 309): Holding Torque Converter
22. Remove the pitching stopper. (Scheme 310): Identifying Pitching Stopper
23. Using ST, disconnect fuel hoses from fuel pipes. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#fuel-injection-fuel-systems-h4dotc), Fuel Delivery, Return and Evaporation lines. > CAUTION: Be careful not to spill fuel. Catch fuel from hoses using a container or cloth. ST 42099AE000 CONNECTOR REMOVER (Scheme 311): Disconnecting Fuel Hoses From Fuel Pipes Using Connector Remover ST 42099AE000
24. Support the engine with a lifting device and wire ropes. (Scheme 312): Lifting Engine With Wire Ropes
25. Support the transmission with a garage 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. (Scheme 313): Supporting Transmission With Garage Jack
26. Separation of the engine and transmission Remove the starter. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/charging-system/#startingcharging-systems-h4so__removal), Starter. > Install the ST to torque converter clutch case. (AT model) ST 498277200 STOPPER SET see scheme 42: Identifying Stopper Set ST 498277200 On Torque Converter Remove the bolts which hold the right upper side of transmission to engine. (Scheme 314): Identifying Engine Transmission Bolts - Right Upper Side
27. Remove the engine from vehicle. Slightly raise the engine. Raise the transmission with garage jack. Move the engine horizontally until the main-shaft is withdrawn from clutch cover. Slowly move the engine away from engine compartment. NOTE: Be careful not to damage adjacent parts or body panels with crank pulley, oil pressure gauge, etc.
28. Remove the front cushion rubbers.

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1. Install the clutch release fork and bearing to transmission. (MT model) < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/clutches-manual-hydraulic/#clutch-system), Release Bearing and Lever. >
2. Install the front cushion rubbers to engine. Tightening torque: 35 N.m (3.6 kgf-m, 25.8 ft-lb)
3. Install the engine onto transmission. Position the engine in engine compartment, and then align it with the transmission. NOTE: Be careful not to damage the adjacent parts or body panels with crank pulley, oil pressure gauge, etc. Apply a small amount of grease to the splines of mainshaft. (MT model)
4. Tighten the bolts which hold the right upper side of transmission to engine. Tightening torque: 50 N.m (5.1 kgf-m, 37 ft-lb) (Scheme 315): Identifying Engine Transmission Bolts - Right Upper Side
5. Remove the lifting device and wire ropes. (Scheme 316): Lifting Engine With Wire Ropes
6. Remove the garage 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) (Scheme 317): Identifying Pitching Stopper
8. Remove the ST from torque converter clutch case. (AT model) NOTE: Be careful not to drop the ST into torque converter clutch case when removing ST. ST 498277200 STOPPER SET
9. Install the starter. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/charging-system/#startingcharging-systems-h4so__installation), Starter. >
10. Install the torque converter clutch onto drive plate. (AT model) Tighten the bolts which hold the torque converter clutch to drive plate. While rotating the crank pulley in the direction of engine rotation little by little using a socket wrench, remove all the bolts. CAUTION: Be careful not to drop bolts into the torque converter clutch housing. Tightening torque: 25 N.m (2.5 kgf-m, 18.4 ft-lb) (Scheme 318): Holding Torque Converter Install the service hole plug.
11. Install the power steering pump on bracket. Install the power steering tank on bracket. (Scheme 319): Locating Reservoir Tank Install the power steering pump. Tightening torque: 20.1 N.m (2.05 kgf-m, 14.8 ft-lb) (Scheme 320): Identifying Power Steering Pump Install the power steering pipe bracket on intake manifold RH. (Scheme 321): Locating Power Steering Pipe With Bracket Install the front side V-belt, and adjust it. < Ref. to «FRONT SIDE BELT»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc__front-side-belt), INSTALLATION, V-belt. >
12. Lift-up the vehicle.
13. Tighten the nuts which hold the lower side of transmission to engine. Tightening torque: 50 N.m (5.1 kgf-m, 37 ft-lb) (Scheme 322): Identifying Engine Transmission Nuts - Lower Side
14. Tighten the nuts which install the front cushion rubber onto crossmember. Tightening torque: 85 N.m (8.7 kgf-m, 62.7 ft-lb) NOTE: Make sure the front cushion rubber mounting bolts (A) and locator (B) are securely installed. (Scheme 323): Identifying Front Cushion Rubber Mounting Bolts
15. Install the ATF cooler pipe to frame. (AT model)
16. Install the center exhaust pipe. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/exhaust/#exhaust-h4dotc-engine), Center Exhaust Pipe. >
17. Lower the vehicle.
18. Connect the following hoses: Fuel delivery hose, return hose and evaporation hose Heater inlet and outlet hoses Brake booster vacuum hose
19. Connect the following connectors and terminals: Engine ground terminal Engine harness connectors Generator connector and terminal A/C compressor connectors Power steering switch connector
20. After connecting each cable, adjust them.
21. Install the air intake system. Install the intercooler. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#intake-induction-h4dotc-engine), 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.
22. Install the A/C pressure hoses. NOTE: Use new O-rings. Tightening torque: 15 N.m (1.5 kgf-m, 10.8 ft-lb) (Scheme 324): Identifying A/C Pressure Hoses
23. Install the radiator. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/cooling-fan/#cooling-system-h4dotc), Radiator. >
24. Install the coolant filler tank. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/cooling-fan/#cooling-system-h4dotc), Coolant Filler Tank. >
25. Install the secondary air pump. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#emission-control-aux-emission-control-devices-h4dotc-engine), Secondary Air Pump. >
26. Install the battery in the vehicle, and then connect the cables.
27. Fill engine coolant. < Ref. to «FILLING OF ENGINE COOLANT»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/cooling-fan/#cooling-system-h4dotc), REPLACEMENT, Engine Coolant. >
28. Charge the A/C system with refrigerant. < Ref. to «PROCEDURE»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/general-servicing-all-makes/#hvac-system-heater-ventilator-and-ac), Refrigerant Charging Procedure. >
29. Remove the front hood stay, and close the front hood.
30. Take off the vehicle from lift arms.

REMOVAL

1. Remove the engine assembly. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc__removal) , Engine Assembly. >
2. Remove the engine mounting from engine assembly.

INSTALLATION

Install in the reverse order of removal.

Tightening torque

Engine mounting

35 N.m (3.6 kgf-m, 25.8 ft-lb)

Make sure there are no cracks or other damage.

Scheme 337

1. After removing the engine from body, secure it in the ST shown below. ST1 498457000 ENGINE STAND ADAPTER RH ST2 498457100 ENGINE STAND ADAPTER LH ST3 499817100 ENGINE STAND (Scheme 325): Identifying ST1 498457000 Engine Stand Adapter RH, ST2 498457100 LH And ST3 499817100 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.

Note. Perform the following procedures with the engine installed to the body.

Scheme 338

1. Loosen the lock bolt (A).
2. Loosen the slider bolt (B).
3. Remove the front side belt (C). (Scheme 326): Identifying Front Side Belt

Scheme 339

Scheme 340

1. Loosen the lock nut (A).
2. Loosen the slider bolt (B). (Scheme 327): Identifying Rear Side Belt
3. Remove the A/C belt.
4. Remove the A/C belt tensioner. (Scheme 328): Identifying A/C Belt Tensioner

FRONT SIDE BELT

Note. Wipe off any oil or water on the belt and pulley.

1. Install the V-belt (C), and tighten the slider bolt so as to obtain the specified belt tension. < Ref. to «INSPECTION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
2. Tighten the lock bolt (A).
3. Tighten the slider bolt (B). Tightening torque: Lock bolt through bolt 25 N.m (2.5 kgf-m, 18.4 ft-lb) Slider bolt: 8 N.m (0.8 kgf-m, 5.9 ft-lb) (Scheme 329): Identifying Front Side Belt

REAR SIDE BELT

1. Install the belt, and tighten the slider bolt (B) so as to obtain the specified belt tension. < Ref. to «INSPECTION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
2. Tighten the lock nut (A). Tightening torque: Lock nut (A) 23 N.m (2.3 kgf-m, 17.0 ft-lb) (Scheme 330): Identifying Rear Side Belt

1. Replace the belts, if cracks, fraying or wear is found.
2. Check the V-belt tension and adjust it if necessary by changing generator installing position and idler pulley installing position.

Belt tension (with belt tension gauge)

(A)

When installing new parts

640 - 780 N (65 - 80 kgf, 144 -175 lbf)

At inspection

490 - 640 N (50 - 65 kgf, 110 - 144 lbf)

(B)

When installing new parts

740 - 880 N (75 - 90 kgf, 166 - 198 lbf)

At inspection

350 - 450 N (36 - 46 kgf, 79 - 101 lbf)

Scheme 341

Belt tension (without belt tension gauge)

(A)

When installing new parts

7 -9 mm (0.276 - 0.354 in)

At inspection

9-11 mm (0.354 - 0.433 in)

(B)

When installing new parts

7.5 - 8.5 mm (0.295 - 0.335 in)

At inspection

9.0 - 10.0 mm (0.354 - 0.394 in)

Scheme 342

Scheme 343

1. Remove the V-belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
2. Remove the crank pulley bolt. To lock the crankshaft, use ST. ST 499977100 CRANK PULLEY WRENCH (Scheme 333): Removing Crank Pulley Bolt Using Crank Pulley Wrench ST 499977100
3. Remove the crank pulley.

1. Install the crank pulley.
2. Install the pulley bolt. To lock the crankshaft, use ST. ST 499977100 CRANK PULLEY WRENCH Clean the crank pulley thread using compressed air. Apply engine oil to the crank 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 crank pulley bolts. Tightening torque: 180 N.m (18.4 kgf-m, 132.8 ft-lb) see scheme 63: Installing Crank Pulley Bolt Using Crank Pulley Wrench ST 499977100
3. Confirm that the tightening angle of crank pulley bolt is 65 degrees or more. If the tightening angle of crank pulley bolt is less than 65 degrees, conduct the following procedures. CAUTION: If the tightening angle of crank pulley bolt is less than 65 degrees, the bolt should be damaged. In this case, the bolt must be replaced. Replace the crank pulley bolts and clean them. Crank pulley bolt: 12369A A011 Clean the crankshaft thread using compressed air. Tighten the bolts temporarily with tightening torque of 44 N.m (4.5 kgf-m, 33 ft-lb). Tighten the crank pulley bolts keeping them in an angle between 65 degrees and 75 degrees. NOTE: Conduct the tightening procedures by confirming the turning angle of crank pulley bolt referring to the gauge indicated on timing belt cover.
4. Install the A/C belt tensioner. see scheme 64: Identifying A/C Belt Tensioner
5. Install the V-belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >

1. Make sure the V-belt is not worn or otherwise damaged.
2. Check the tension of the belt. < Ref. to «INSPECTION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc) , V-belt. >

Scheme 344

1. Remove the V-belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
2. Remove the crank pulley. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
3. Remove the timing belt cover (LH) (A).
4. Remove the timing belt cover (RH) (B).
5. Remove the front timing belt cover (C). (Scheme 334): Identifying Front Timing Belt Cover

1. Install the front timing belt cover (C). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb)
2. Install the timing belt cover (RH) (B). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb)
3. Install the timing belt cover (LH) (A). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb) see scheme 66: Identifying Front Timing Belt Cover
4. Install the crank pulley. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
5. Install the V-belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >

Make sure the cover is not damaged.

Scheme 345

Scheme 346

Scheme 347

Scheme 348

Scheme 349

Scheme 350

Scheme 351

Scheme 352

Scheme 353

1. Remove the V-belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
2. Remove the crank pulley. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
3. Remove the timing belt cover. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
4. Remove the timing belt guides. (MT model) see scheme 67: Identifying Timing Belt Guides (1 Of 4) see scheme 68: Identifying Timing Belt Guides (2 Of 4) see scheme 69: Identifying Timing Belt Guides (3 Of 4) (Scheme 335): Identifying Timing Belt Guides (4 Of 4)
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 the alignment marks on crank sprocket, intake cam sprocket (LH), exhaust cam sprocket (LH), intake cam sprocket (RH) and exhaust cam sprocket (RH) with notches of timing belt cover and cylinder block. ST 499987500 CRANKSHAFT SOCKET (Scheme 336): Aligning Marks On Crank Sprocket Using Crankshaft Socket ST 499987500 Using white paint, put alignment and/or arrow marks on the timing belts in relation to the sprockets. see scheme 72: Aligning Marks On Timing Belts (Scheme 337): Identifying Timing Belts Position Z 1: 54.5 tooth length Z 2: 51 tooth length Z 3: 28 tooth length (Scheme 338): Identifying Timing Belt Tooth Length
6. Remove the belt idler (A). (Scheme 339): Identifying Belt Idler
7. Remove the timing belt. CAUTION: After the timing belt has been removed, never rotate the intake and exhaust, cam sprocket. If the cam sprocket is rotated, the intake and exhaust valve heads strike together and valve stems are bent.

Scheme 354

Scheme 355

Scheme 356

1. Remove the belt idler (B) and (C). (Scheme 340): Identifying Belt Idler
2. Remove the belt idler No. 2. see scheme 77: Identifying Belt Idler No. 2
3. Remove the automatic belt tension adjuster assembly. see scheme 78: Identifying Automatic Belt Tension Adjuster Assembly

Scheme 357

Scheme 358

Scheme 359

Scheme 360

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. Press-in the push adjuster rod gradually taking more than 3 minutes. Do not allow press pressure to exceed 9,807 N (1,000 kgf, 2,205 lbf). Press the adjuster rod as far as the end surface of 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 lbf) or more until the adjuster rod is aligned with the stopper pin hole in the cylinder. (Scheme 341): Pressing Adjuster Rod With a 2 mm (0.08 in) dia. stopper pin or a 2 mm (nominal) dia. hex bar wrench inserted into the stopper pin hole in the cylinder, secure the adjuster rod. (Scheme 342): Identifying Stopper Pin Hole In Cylinder
2. Install the automatic belt tension adjuster assembly. Tightening torque: 39 N.m (4.0 kgf-m, 28.9 ft-lb) (Scheme 343): Identifying Automatic Belt Tension Adjuster Assembly
3. Install the belt idler No. 2. Tightening torque: 39 N.m (4.0 kgf-m, 28.9 ft-lb) see scheme 82: Identifying Belt Idler No. 2
4. Install the belt idlers. Tightening torque: 39 N.m (4.0 kgf-m, 28.9 ft-lb) see scheme 83: Identifying Belt Idlers

Scheme 361

Scheme 362

Scheme 363

Scheme 364

Scheme 365

Scheme 366

Scheme 367

Scheme 368

Scheme 369

Scheme 370

Scheme 371

Scheme 372

Scheme 373

1. Preparation for installation of automatic belt tension adjuster assembly. < Ref. to «AUTOMATIC BELT TENSION ADJUSTER ASSEMBLY AND BELT IDLER»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), INSTALLATION, Timing Belt. >
2. Crankshaft and cam sprocket alignment Align mark (A) on the crank sprocket with mark on the oil pump cover at cylinder block. (Scheme 344): Aligning Mark On Crank Sprocket With Mark On Oil Pump Cover Cylinder Block Align single line mark (A) on the exhaust cam sprocket (RH) with notch (B) on timing belt cover. see scheme 85: Aligning Single Line Mark On Exhaust Cam Sprocket Align single line mark (A) on the intake cam sprocket (RH) with notch (B) on timing belt cover. (Make sure double lines (C) on intake camshaft and exhaust cam sprockets are aligned.) (Scheme 345): Aligning Single Line Mark On Intake Cam Sprocket Align single line mark (A) on exhaust cam sprocket (LH) with notch (B) on timing belt cover by turning the sprocket counterclockwise (as viewed from front of engine). (Scheme 346): Aligning Single Line Mark On Exhaust Cam Sprocket Align the single line mark (A) on intake cam sprocket (LH) with notch (B) on timing belt cover by turning the sprocket clockwise (as viewed from front of engine). (Ensure the double lines (C) on intake and exhaust cam sprockets are aligned.) (Scheme 347): Aligning Single Line Mark On Intake Cam Sprocket Ensure the camshaft and crank 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. (Scheme 348): Identifying Intake And Exhaust Camshafts Position 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, #2 intake and #4 exhaust cam of camshafts (LH) are held to push their corresponding valves down. (Under this condition, these valves are held lifted.) Camshafts (RH) are held so that their cams do not push valves down. Camshafts (LH) 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 by the upper illustration in the figure as this causes both intake and exhaust valves to lift simultaneously, resulting in interference with their heads. (Scheme 349): Aligning Mark On Timing Belt With Marks On Sprockets
3. Installation of timing belt Align the alignment mark on timing belt with marks on sprockets in 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. (Scheme 350): View Of Timing Belt
4. Install the belt idler. Tightening torque: 39 N.m (4.0 kgf-m, 28.9 ft-lb) NOTE: Make sure that the marks on the timing belt and sprockets are aligned. (Scheme 351): Identifying Belt Idler
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 model) CAUTION: Before installing the bolts, clean the threaded portion of timing belt cover. Apply liquid gasket to the threaded portion of bolts. (Cam sprocket side only) Liquid gasket: THREE BOND 1324 (Part No. 004403042) or equivalent Temporarily tighten the bolts. Check and adjust the clearance between timing belt and timing belt guide. Clearance: 1.0±0.5 mm (0.039±0.020 in) (Scheme 352): Identifying Clearance Between Timing Belt And Timing Belt Guide (1 Of 4) (Scheme 353): Identifying Clearance Between Timing Belt And Timing Belt Guide (2 Of 4) (Scheme 354): Identifying Clearance Between Timing Belt And Timing Belt Guide (3 Of 4) (Scheme 355): Identifying Clearance Between Timing Belt And Timing Belt Guide (4 Of 4) Tighten the bolts. Tightening torque: 9.75 N.m (1.0 kgf-m, 7.2 ft-lb) (Scheme 356): Identifying Timing Belt Guide Bolts (1 Of 4) Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) (Scheme 357): Identifying Timing Belt Guide Bolts (2 Of 4) Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) (Scheme 358): Identifying Timing Belt Guide Bolts (3 Of 4) Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) (Scheme 359): Identifying Timing Belt Guide Bolts (4 Of 4)
7. Install the timing belt cover. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
8. Install the crank pulley. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
9. Install the V-belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >

Scheme 374

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 timing belt; if any crack is found, replace the timing belt. CAUTION: Be careful not to let oil, grease or coolant contact the timing belt. Remove quickly and thoroughly if this happens. Do not bend the timing belt sharply. Bending diameter h: 60 mm (2.36 in) or more see scheme 101: Identifying Timing Belt Bending Diameter

Scheme 375

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. NOTE: Slight traces of oil at rod's oil seal does not indicate a problem.
2. Check that the adjuster rod does not move when a pressure of 294 N (30 kgf, 66 lbf) 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 lbf), 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 lbf) 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 3 minutes. Do not allow press pressure to exceed 9,807 N (1,000 kgf, 2,205 lbf). 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.
4. 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) (Scheme 360): Measuring Extension Of Rod Beyond Body

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 belt 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 belt idler for grease leakage.

Scheme 376

Scheme 377

1. Remove the V-belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
2. Remove the crank pulley. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
3. Remove the timing belt cover. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
4. Remove the timing belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
5. Remove the cam sprockets. To lock the camshaft, use ST. ST 499207400 CAM SPROCKET WRENCH (Scheme 361): Removing Cam Sprockets Using Cam Sprocket Wrench ST 499207400 ST 499977500 CAM SPROCKET WRENCH (Scheme 362): Installing Cam Sprockets Using Cam Sprocket Wrench ST 499977500

1. Install the cam sprocket. To lock the camshaft, use ST. ST 499207400 CAM SPROCKET WRENCH Tightening torque: Tighten to 30 N.m (3.1 kgf-m, 22.1 ft-lb), then further tighten by 45°. NOTE: Do not confuse the cam sprockets (RH) and (LH) intake side during installation. (Scheme 363): Installing Cam Sprocket Using Cam Sprocket Wrench ST 499207400 ST 499977500 CAM SPROCKET WRENCH Tightening torque: Tighten to 30 N.m (3.1 kgf-m, 22.1 ft-lb), then further tighten by 45°. (Scheme 364): Installing Cam Sprockets Using Cam Sprocket Wrench ST 499977500
2. Install the timing belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
3. Install the timing belt cover. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
4. Install the crank pulley. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
5. Install the V-belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >

1. Check the cam sprocket teeth for abnormal wear and scratches.
2. Make sure there is no free play between cam sprocket and key.

Scheme 378

1. Remove the V-belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
2. Remove the crank pulley. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
3. Remove the timing belt cover. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
4. Remove the timing belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
5. Remove the crank sprocket. see scheme 107: Identifying Crank Sprocket

1. Install the crank sprocket. (Scheme 365): Identifying Crank Sprocket
2. Install the timing belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
3. Install the timing belt cover. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
4. Install the crank pulley. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
5. Install the V-belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >

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

Scheme 379

Scheme 380

Scheme 381

Scheme 382

Scheme 383

Scheme 384

Scheme 385

1. Remove the V-belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
2. Remove the crank pulley. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
3. Remove the timing belt cover. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
4. Remove the timing belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
5. Remove the cam sprocket. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Cam Sprocket. >
6. Disconnect the oil flow control solenoid valve assembly connector. (Scheme 366): Identifying Oil Flow Control Solenoid Valve Assembly Connector
7. Remove the tensioner bracket. (Scheme 367): Identifying Tensioner Bracket
8. Remove the timing belt cover No. 2 (LH). (Scheme 368): Identifying Timing Belt Cover No. 2 (LH)
9. Remove the timing belt cover No. 2 (RH). (Scheme 369): Identifying Timing Belt Cover No. 2 (RH)
10. Remove the spark plug cord.
11. Remove the oil level gauge guide. (LH side)
12. Remove the rocker cover and gasket.
13. Remove the oil pipe. (Scheme 370): Identifying Union Screw With Oil Pipe
14. Loosen the oil flow control solenoid valve assembly and intake camshaft cap bolts equally, a little at a time in alphabetical sequence shown in the figure. (Scheme 371): Identifying Intake Camshaft Cap Bolts
15. Loosen the exhaust camshaft cap bolts equally, a little at a time in alphabetical sequence shown in the figure. (Scheme 372): Identifying Exhaust Camshaft Cap Bolts
16. Remove the oil flow control solenoid valve assembly, intake camshaft cap, and camshaft.
17. Remove the exhaust camshaft cap and camshaft. NOTE: Arrange the camshaft caps in order so that they can be installed in their original positions.
18. Similarly, remove the camshafts (RH) and related parts.

Scheme 386

Scheme 387

Scheme 388

Scheme 389

Scheme 390

Scheme 391

Scheme 392

1. Camshaft installation Apply engine oil to the cylinder head at camshaft bearing installing location before installing the camshaft. Install the camshaft so that each valve is close to or in contact with "base circle" of cam lobe. NOTE: When the camshafts are positioned as shown in the figure, camshaft (LH) needs to be rotated at a minimum to align with the timing belt during installation. Camshaft (RH) need not be rotated when set at the position shown in the figure. Intake camshaft (LH): Rotate 80° clockwise. Exhaust camshaft (LH): Rotate 45° counterclockwise. (Scheme 373): Identifying Intake Camshaft And Exhaust Camshaft Position
2. Camshaft cap and oil flow control solenoid valve assembly installation Apply small amount of liquid gasket to the cap mating surface. NOTE: Do not apply liquid gasket excessively. Otherwise, the excessive liquid gasket may come out and flow toward oil seal, resulting in oil leaks. Liquid gasket: THREE BOND 1215 (Part No. 004403007) or equivalent see scheme 117: Applying Small Amount Of Liquid Gasket To Cap Mating Surface Apply engine oil to the cap bearing surface, and install the cap on camshaft as shown by identification mark. Gradually tighten the camshaft cap and oil control valve assembly in at least two stages in alphabetical sequence shown in the figure, and then tighten to specified torque. Tightening torque: T1: 9.75 N.m (1.0 kgf-m, 7.2 ft-lb) T2: 20 N.m (2.0 kgf-m, 14.8 ft-lb) see scheme 118: Identifying Camshaft Bearing Bolts After tightening the camshaft cap, ensure the camshaft rotates only slightly while holding it at "base" circle.
3. Camshaft oil seal installation Apply grease to the new oil seal lips and press onto front end of camshaft by using ST1 and ST2. NOTE: Use a new oil seal. ST1 499587600 OIL SEAL GUIDE ST2 499597200 OIL SEAL GUIDE see scheme 119: Tapping Camshaft Oil Seal Using Oil Seal Guide ST1 499587600
4. Rocker cover installation Install the gasket on rocker cover. Install the peripheral gasket and ignition coil gasket. Apply liquid gasket to the designated point of cylinder head. NOTE: Apply liquid gasket to the half moon plug portion with sticking out more than 5 mm (0.2 in). Liquid gasket: THREE BOND 1215 (Part No. 004403007) or equivalent (Scheme 374): Applying Liquid Gasket To Cylinder Head Install the rocker cover on cylinder head. Ensure the gasket is properly positioned during installation. CAUTION: Use a new rocker cover gasket. Tighten the rocker cover tightening bolts in alphabetical sequence shown in the figure, and then tighten to specified torque. Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) (Scheme 375): Identifying Rocker Cover Bolts Tightening Sequence
5. Install the oil pipe. NOTE: Installing location of the union screw varies depending on with or without filter. Be careful of this. Tightening torque: 29 N.m (3.0 kgf-m, 21.4 ft-lb) (Scheme 376): Identifying Union Screw And Oil Pipe
6. Connect the oil flow control solenoid valve connector. (Scheme 377): Identifying Oil Flow Control Solenoid Valve Connector
7. Similarly, install the parts on RH side.
8. Install the timing belt cover No. 2 (RH). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb) see scheme 124: Identifying Timing Belt Cover Bolts (RH)
9. Install the timing belt cover No. 2 (LH). Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb) see scheme 125: Tightening Timing Belt Cover Bolts (LH)
10. Install the tensioner bracket. Tightening torque: 24.5 N.m (2.5 kgf-m, 18.1 ft-lb) (Scheme 378): Identifying Tensioner Bracket
11. Install the cam sprocket. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Cam Sprocket. >
12. Install the timing belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
13. Install the timing belt cover. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
14. Install the crank pulley. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
15. Install the V-belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >

Scheme 393

Scheme 394

Scheme 395

Scheme 396

Scheme 397

1. Measure the bend, and repair or replace if necessary. Limit: 0.020 mm (0.0008 in) see scheme 127: Measuring Camshaft Runout
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 within standard, check the oil clearance. CAMSHAFT JOURNAL Camshaft journal Front Center, rear Standard mm (in) 37.946 - 37.963 (1.4939 - 1.4946) 29.946 - 29.963 (1.1790 - 1.1796)
4. Measurement of the camshaft journal oil clearance Clean the bearing caps and camshaft journals. Place the camshafts on 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. Do not turn the camshaft. Tightening torque: T1: 9.75 N.m (1.0 kgf-m, 7.2 ft-lb) T2: 20 N.m (2.0 kgf-m, 14.8 ft-lb) (Scheme 379): Identifying Camshaft Bearing Caps Bolts 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) (Scheme 380): Measuring Widest Point Of Plastigage Completely remove the plastigage.
5. Check the cam face condition, and remove the minor faults by grinding with oil stone. Measure the cam height H. If it exceeds the limit or offset wear occurs, replace the camshaft. Cam height H: Standard Intake 46.55 - 46.65 mm (1.833 - 1.837 in) Exhaust 46.75 - 46.85 mm (1.841 - 1.844 in) Limit Intake 46.45 mm (1.829 in) Exhaust 46.65 mm (1.837 in) Cam base circle diameter A: 37.0 mm (1.457 in) (Scheme 381): Identifying Cam Height
6. Measure the thrust clearance of camshaft with dial gauge. If the thrust clearance exceeds the limit or offset wear occurs, replace the caps and cylinder head as a set. If necessary, replace the camshaft. Standard: 0.068 - 0.116 mm (0.0027 - 0.0046 in) Limit: 0.14 mm (0.0055 in) (Scheme 382): Measuring Thrust Clearance Of Camshaft

Scheme 398

1. Remove the V-belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
2. Remove the crank pulley. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
3. Remove the timing belt cover. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
4. Remove the timing belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
5. Remove the cam sprockets. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Cam Sprocket. >
6. Remove the intake manifold. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#fuel-injection-fuel-systems-h4dotc), Intake Manifold. >
7. Remove the bolt which installs the A/C compressor bracket on cylinder head.
8. Remove the camshaft. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Camshaft. >
9. Remove the cylinder head bolts in alphabetical sequence shown in the figure. Leave bolts (A) and (D) engaged by three or four threads to prevent the cylinder head from falling. (Scheme 383): Identifying Cylinder Head Bolts (1 Of 2)
10. While tapping the cylinder head with a plastic hammer, separate it from cylinder block. Remove the bolts (A) and (D) to remove cylinder head. (Scheme 384): Identifying Cylinder Head Bolts (2 Of 2)
11. Remove the cylinder head gasket. CAUTION: Be careful not to scratch the mating surface of cylinder head and cylinder block.
12. Similarly, remove the cylinder head (RH).

Scheme 399

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 the washers and bolt threads. Tighten all bolts to 29 N.m (3.0 kgf-m, 22 ft-lb) in alphabetical sequence. Tighten all bolts to 69 N.m (7.0 kgf-m, 51 ft-lb) in alphabetical sequence again. Back off all bolts by 180° first; back them off by 180° again in reverse order of installation. Tighten all bolts to 49 N.m (5.0 kgf-m, 36 ft-lb) in alphabetical sequence. Tighten all bolts 80 to 90° in alphabetical sequence. Tighten all bolts by 40 to 45° in alphabetical sequence again. CAUTION: Do not tighten the bolts by more than 45°. Further tighten all bolts (A) and (B) by 40 to 45°. CAUTION: Ensure that the total "re-tightening angle" in the previous two steps do not exceed 90°. (Scheme 385): Identifying Cylinder Head Bolts Tightening Sequence
3. Install the camshaft. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Camshaft. >
4. Install the A/C compressor bracket on cylinder head.
5. Install the intake manifold. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#fuel-injection-fuel-systems-h4dotc), Intake Manifold. >
6. Install the cam sprocket. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Cam Sprocket. >
7. Install the timing belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
8. Install the timing belt cover. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
9. Install the crank pulley. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
10. Install the V-belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >

Scheme 400

1. Remove the 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 NOTE: Keep the removed parts in order for re-installing in their original positions. CAUTION: 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 386): Identifying ST1 498267600 Cylinder Head Table, ST2 499718000 Valve Spring Remover

Scheme 401

1. Installation of valve spring and valve: Coat the stem of each valve with engine oil and insert the valve into valve guide. NOTE: 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 NOTE: Be sure to install the valve springs with their close-coiled end facing the seat on cylinder head. (Scheme 388): Identifying ST1 498267600 Cylinder Head Table, ST2 499718000 Valve Spring Remover Compress the valve spring, and then 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.
3. Install the valve lifter.

Scheme 402

1. Make sure that no crack or other damage exists. In addition to visual inspection, inspect the important areas by means of liquid penetrant tester.
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 0.035 mm (0.0014 in), re-grind the surface with a surface grinder. Warping limit: 0.035 mm (0.0014 in) Grinding limit: 0.3 mm (0.012 in) Standard height of cylinder head: 127.5 mm (5.02 in) NOTE: Uneven torque for the cylinder head nuts can cause warping. When reassembling, pay special attention to the torque so as to tighten evenly. (Scheme 389): Measuring Warping Of Cylinder Head Surface

VALVE SEAT

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

Valve seat contact width W

Intake

Standard 0.6 - 1.4 mm (0.024 - 0.055 in) Limit 1.7 mm (0.067 in)

Exhaust

Standard 1.2 - 1.8 mm (0.047-0.071 in)

Limit 2.2 mm (0.087 in)

Scheme 403

Scheme 404

Scheme 405

Scheme 406

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 standard value, 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 (0.2344 - 0.2350 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 (Scheme 391): Inserting ST2 Into Valve Guide Turn the cylinder head upside down and place ST as shown in the figure. ST 18251AA020 VALVE GUIDE ADJUSTER (Scheme 392): Identifying Valve Guide Adjuster ST 18251AA020 On Cylinder Head 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. 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 see scheme 142: Inserting ST1 Into Valve Guide Check the valve guide protrusion. Valve guide protrusion L: 15.8 - 16.2 mm (0.622 - 0.638 in) 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 NOTE: 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 chip, use a new reamer or remedy the reamer. Recheck the contact condition between valve and valve seat after replacing the valve guide.

Scheme 407

1. Inspect the flange and stem of valve, and replace if damaged, worn, or deformed, or if "H" is exceeds the standard value. H: Intake (A) Standard 1.0 - 1.4 mm (0.039 - 0.055 in) Limit 0.8 mm (0.031 in) Exhaust (B) Standard 1.3 -1.7 mm (0.051 - 0.067 in) Limit 0.8 mm (0.031 in) see scheme 143: Inspecting Intake And Exhaust Valve Flange And Stem
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. NOTE: Replace the valve oil seal with new one after lapping. Intake valve and exhaust valve can be identified by their overall length. Valve overall length: Intake (A) 104.4 mm (4.110 in) Exhaust (B) 104.65 mm (4.120 in)

VALVE SPRINGS

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 valve spring, stand the spring on a surface plate and measure its deflection at the top using a try square.

VALVE SPRINGS LENGTH

Scheme 408

INTAKE AND EXHAUST VALVE OIL SEAL

In the following case, pinch and remove the oil seal from valve using pliers, and then replace it with a new one.

1. When the lip is damaged.
2. When the spring is out of the specified position.
3. When readjusting the surfaces of intake valve and valve sheet.
4. When replacing the intake valve guide.

1. Place the cylinder head on ST1.
2. Using ST2, press-fit the oil seal.

ST1 498267600 CYLINDER HEAD TABLE

ST2 498857100 VALVE OIL SEAL GUIDE

Color of rubber part

Intake [Gray] Exhaust [Green]

Scheme 409

Scheme 410

1. Visually check the valve lifter.
2. Measure the outer diameter of valve lifter. Outer diameter: 34.959 - 34.975 mm (1.3763 - 1.3770 in) (Scheme 393): Measuring Outer Diameter Of Valve Lifter
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)

Scheme 411

Note. If difference between outer diameter of valve lifter and inner diameter of valve lifter mating part is over the standard, replace the cylinder head.

Standard

0.019 - 0.057 mm (0.0007 - 0.0022 in)

Limit

0.100 mm (0.0039 in)

DISPOSAL

If the valve is damaged, remove the valve and neutralize it by immersing it in water, and dispose of it in the same way that general steel materials are disposed of. The disposal method is described in the following.

Scheme 412

1. Wearing rubber gloves, remove the damaged valve from the cylinder head.
2. Prepare a large receptacle (bucket or other container) in a well ventilated location, and fill the receptacle with water (at least 10 liters).
3. Immerse the damaged valve in the receptacle. CAUTION: A severe reaction may occur, so stand at least 2 - 3m from the receptacle. Because the reaction will produce hydrogen gas, moreover, keep the receptacle away from sparks or flames.
4. Once the reaction is completed (about 4 - 5 hours have elapsed), carefully remove the valve using large pincers so that the reaction liquid does not contact your skin, and dispose of it with other parts that are being disposed of.
5. The reaction liquid is a strong alkaline solution, so it must be disposed of in accordance with local regulations. CAUTION: Make sure the reaction liquid does not contact your skin. If contact with skin occurs, immediately wash the affected area with large quantities of water. (Scheme 395): Disposing Of Valve

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

Scheme 413

Scheme 414

Scheme 415

Scheme 416

Scheme 417

Scheme 418

Scheme 419

Scheme 420

1. Remove the intake manifold. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#fuel-injection-fuel-systems-h4dotc), Intake Manifold. >
2. Remove the V-belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
3. Remove the crank pulley. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
4. Remove the timing belt cover. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
5. Remove the timing belt. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
6. Remove the cam sprockets. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Cam Sprocket. >
7. Remove the crank sprocket. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Sprocket. >
8. Remove the generator and A/C compressor with their brackets.
9. Remove the cylinder head. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Cylinder Head. >
10. Remove the clutch disc and cover. (MT model) < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/clutches-manual-hydraulic/#clutch-system__removal), Clutch Disc and Cover. >
11. Remove the flywheel. (MT model) < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/clutches-manual-hydraulic/#clutch-system), Flywheel. > ST 498497100 CRANKSHAFT STOPPER (Scheme 396): Identifying Crankshaft Stopper ST 498497100 On Flywheel
12. Remove the oil separator cover.
13. Remove the water bypass pipe for heater.
14. Remove the oil filter. ST 18332AA010 OIL FILTER WRENCH (Outer diameter: 65 mm (2.56 in)) ST 18332AA000 OIL FILTER WRENCH (Outer diameter: 68 mm (2.68 in))
15. Remove the oil cooler. (Scheme 397): Exploded View Of Oil Cooler Components
16. Remove the water pump.
17. Remove the oil pump from cylinder block. NOTE: If disassembling or inspecting the oil pump, loosen the plug of relief valve before removing the oil pump. Remove the oil pump from cylinder block. Use a flat tip screwdriver when removing the oil pump. CAUTION: Be careful not to scratch the mating surface of cylinder block and oil pump. (Scheme 398): Identifying Oil Pump From Cylinder Block
18. Removal of oil pan: Turn the cylinder block with #2 and #4 piston sides facing upward. Remove the bolts which secure oil pan to cylinder block. Insert an oil pan cutter blade between cylinder block-to-oil pan clearance, and then remove the oil pan. CAUTION: Do not use a screwdriver or similar tool in place of oil pan cutter.
19. Remove the oil strainer stay.
20. Remove the oil strainer.
21. Remove the baffle plate.
22. Remove the water pipes. see scheme 152: Identifying Service Hole Plug, Service Hole Cover, Piston Pin And O-Ring
23. Remove the service hole cover and service hole plugs using hexagon wrench [14 mm]. (Scheme 399): Identifying Service Hole Plugs
24. Rotate the crankshaft to bring #1 and #2 pistons to bottom dead center position, and then remove the piston snap ring through service hole of #1 and #2 cylinders. (Scheme 400): Identifying Piston Snap Ring
25. Draw out the piston pin from #1 and #2 pistons using ST. ST 499097700 PISTON PIN REMOVER NOTE: Be careful not to confuse the original combination of piston, piston pin and cylinder. (Scheme 401): Removing Piston Pin Using Piston Pin Remover ST 499097700
26. Similarly remove the piston pins from #3 and #4 pistons.
27. Remove the bolts which connect the cylinder block on the side of #2 and #4 cylinders.
28. Back off the bolts which connect the cylinder block on the side of #1 and #3 cylinders two or three turns.
29. Set up the cylinder block so that #1 and #3 cylinders are on the upper side, then remove the cylinder block connecting bolts.
30. Separate the cylinder blocks (LH) and (RH). NOTE: When separating the cylinder block, do not allow the connecting rod to fall and damage the cylinder block. see scheme 156: Exploded View Of Cylinder Block Components
31. Remove the rear oil seal.
32. Remove the crankshaft together with connecting rod.
33. Remove the crankshaft bearings from cylinder block using a hammer handle. NOTE: Do not confuse the combination of crankshaft bearings. Press the bearing at the end opposite to locking lip.
34. Draw out each piston from cylinder block using a hammer handle. NOTE: Do not confuse the combination of piston and cylinder.

Scheme 421

Scheme 422

Scheme 423

Scheme 424

Scheme 425

Scheme 426

Scheme 427

Scheme 428

Scheme 429

Scheme 430

Scheme 431

Scheme 432

Scheme 433

Scheme 434

Scheme 435

Scheme 436

Scheme 437

Scheme 438

Scheme 439

Scheme 440

Scheme 441

Scheme 442

Scheme 443

Scheme 444

Scheme 445

Scheme 446

Scheme 447

Scheme 448

1. Remove oil in the mating surface of bearing and cylinder block before installation. Also apply a coat of engine oil to crankshaft pins.
2. Install the crankshaft bearing to cylinder block, apply a thin coat of engine oil to crankshaft bearing, and position the crankshaft on #2 and #4 cylinder block.
3. Apply liquid gasket to the mating surface of #1 and #3 cylinder block, and position it on #2 and #4 cylinder block. Liquid gasket: Part No. 004403007 THREE BOND 1215 or equivalent NOTE: Do not allow liquid gasket to jut into O-ring grooves, oil passages, bearing grooves, etc. (Scheme 403): Applying Liquid Gasket To Cylinder Block
4. Apply engine oil to washers and thread of bolts.
5. Tighten the 10 mm cylinder block connecting bolts in alphabetical sequence shown in the figure. (LH side) Tightening torque: 10 N.m (1.0 kgf-m, 7.4 ft-lb) (Scheme 404): Identifying Cylinder Block Bolts Tightening Sequence (LH Side)
6. Tighten the 10 mm cylinder block connecting bolts in alphabetical sequence shown in the figure. (RH side) Tightening torque: 10 N.m (1.0 kgf-m, 7.4 ft-lb) (Scheme 405): Identifying Cylinder Block Bolts Tightening Sequence (RH Side)
7. Tighten the LH side bolts (A - D) in alphabetical sequence. Tightening torque: 18 N.m (1.8 kgf-m, 13.3 ft-lb) (Scheme 406): Identifying Cylinder Block Bolts Tightening Sequence (LH Side)
8. Tighten the RH side bolts (E - J) in alphabetical sequence. Tightening torque: 18 N.m (1.8 kgf-m, 13.3 ft-lb) (Scheme 407): Identifying Cylinder Block Bolts Tightening Sequence (RH Side)
9. Further tighten the LH side bolts (A - D) in alphabetical sequence, by 90° for (A) and (C), and to 40 N.m (4.1 kgf-m, 29.5 ft-lb) for (B) and (D). (Scheme 408): Identifying Cylinder Block Bolts Tightening Sequence (LH Side)
10. Further tighten the RH side bolts (E - J) to 90° in alphabetical sequence. (Scheme 409): Identifying Cylinder Block Bolts Tightening Sequence (RH Side)
11. 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, 18.4 ft-lb) (H): 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) (Scheme 410): Identifying Cylinder Block Bolts Tightening Sequence
12. Install the rear oil seal using ST1 and ST2. ST1 499597100 CRANKSHAFT OIL SEAL GUIDE ST2 499587200 CRANKSHAFT OIL SEAL INSTALLER (Scheme 411): Installing Rear Oil Seal Using ST1 And ST2 NOTE: Use a new rear oil seal.
13. Position the top ring gap at (A) or (B) in the figure.
14. Position the second ring gap at 180° on the reverse side for the top ring gap. (Scheme 412): Identifying Top Ring Gap Position
15. Position the upper rail gap at (C) in the figure. (Scheme 413): Identifying Upper Rail Gap Position
16. Align upper rail spin stopper (E) with piston side surface hole (D). (Scheme 414): Aligning Upper Rail Spin Stopper With Piston Side Surface Hole
17. Position the expander gap at (F) in the figure. (Scheme 415): Identifying Expander Ring Gap Position
18. Position the lower rail gap at (G) in the figure. (Scheme 416): Identifying Lower Rail Gap Position CAUTION: Ensure ring gaps do not face the same direction. Ensure ring gaps are not within the piston skirt area.
19. Install the snap ring. Install the snap rings in piston holes located opposite of service holes in cylinder block, when positioning all pistons in the corresponding cylinders. NOTE: Use new snap rings. (Scheme 417): Identifying Snap Rings Installation Position (Scheme 418): Applying Coat Of Engine Oil To Pistons And Cylinders With Torque Specifications Tightening torque: N.m (kgf-m, ft-lb) T: 70(7.1, 51.6)
20. Installing the piston Turn the cylinder block so that #1 and #2 cylinders face upward. Using the ST1, turn the crankshaft so that #1 and #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 498747300 PISTON GUIDE (Scheme 419): Inserting Pistons In Cylinders Using Piston Guide ST2 498747300 NOTE: Piston front mark faces towards the front of the engine. (Scheme 420): Identifying Piston Front Mark
21. Installing piston pin Apply a coat of engine oil to ST3. Insert ST3 into the service hole to align piston pin hole with connecting rod small end. ST3 499017100 PISTON PIN GUIDE (Scheme 421): Inserting ST3 Into Service Hole To Aligning Piston Pin Hole With Connecting Rod Small End Apply a coat of engine oil to the piston pin and insert piston pin into piston and connecting rod through service hole. Install the snap ring. NOTE: Use new snap rings. (Scheme 422): Identifying Snap Ring Apply liquid gasket around the service hole plug. Liquid gasket: Part No. 004403010 THREE BOND 1105 or equivalent (Scheme 423): Identifying Piston Install the service hole plug and gasket. NOTE: Use a new gasket. (Scheme 424): Identifying Service Hole Plug see scheme 180: Applying Oil To Piston And Cylinder Block With Torque Specifications Turn the cylinder block so that #3 and #4 cylinders face upward. Using the same procedures as used for #1 and #2 cylinders, install the pistons and piston pins.
22. Install the water pipe.
23. Install the baffle plate. Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb)
24. Install the oil strainer and O-ring. Tightening torque: 10 N.m (1.0 kgf-m, 7.4 ft-lb)
25. Install the oil strainer stay.
26. Apply liquid gasket to the matching surfaces, and then install the oil pan. NOTE: Install it within 20 min. after applying liquid gasket. Liquid gasket: Part No. 004403012 THREE BOND 1207C or equivalent Tightening torque: 5 N.m (0.5 kgf-m, 3.6 ft-lb) (Scheme 425): Applying Liquid Gasket To Oil Pan
27. Apply liquid gasket to the mating surfaces and threaded portion of bolt (A) as shown in the figure, and then install the oil separator cover. Liquid gasket: Mating surface Part No. 004403012 THREE BOND 1207C or equivalent Threaded portion of bolt (A) Part No. 004403042 THREE BOND 1324 or equivalent Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) see scheme 182: Applying Liquid Gasket To Oil Separator Cover
28. Install the flywheel. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/clutches-manual-hydraulic/#clutch-system), Flywheel. >
29. Install the clutch disc and cover. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/clutches-manual-hydraulic/#clutch-system__installation), Clutch Disc and Cover. >
30. Installation of oil pump: Discard the front oil seal after removal. Replace with a new one using the ST. ST 499587100 OIL SEAL INSTALLER see scheme 183: Tapping Oil Seal Using ST Oil Seal Installer 499587100 Apply liquid gasket to the matching surface of oil pump. Liquid gasket: Part No. 004403007 THREE BOND 1215 or equivalent (Scheme 426): Applying Liquid Gasket To Oil Pump Apply a coat of engine oil to the inside of the oil seal. (Scheme 427): Applying Engine Oil To Oil Seal Install the oil pump on cylinder block. Be careful not to damage the oil seal during installation. Apply liquid gasket to the threaded portion of three bolts. 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. Liquid gasket: THREE BOND 1324 (Part No. 004403042) or equivalent Tightening torque: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) (Scheme 428): Identifying Water Pump And Gasket
31. 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 the bolts in two stages in alphabetical sequence as shown in the figure. (Scheme 429): Identifying Water Pump Bolts
32. Install the water bypass pipe for heater.
33. Install the oil cooler. CAUTION: Use a new O-ring. Tightening torque: T1:45 N.m (4.6 kgf-m, 33 ft-lb) T2: 6.4 N.m (0.65 kgf-m, 4.7 ft-lb) T3: 54 N.m (5.3 kgf-m, 40 ft-lb) T4: 69 N.m (7.0 kgf-m, 50.9 ft-lb) (Scheme 430): Identifying Oil Cooler Components
34. Install the oil filter using ST. ST 18332AA000 OIL FILTER WRENCH (Outer diameter: 68 mm (2.68 in)) ST 18332AA010 OIL FILTER WRENCH (Outer diameter: 65 mm (2.56 in))
35. Install the oil filter by turning it by hand, being careful not to damage the seal rubber. Tighten the oil filter 68 mm (2.68 in) in diameter by approx. 1 rotation more after the seal rubber of oil filter comes in contact with oil cooler. If using a torque wrench, tighten it to 14 N.m (1.4 kgf-m, 10.3 ft-lb). Tighten the oil filter 65 mm (2.56 in) in diameter by approx. 2/3 - 3/4 rotation more after the seal rubber of oil filter comes in contact with oil cooler. If using a torque wrench, tighten it to 12 N.m (1.2 kgf-m, 8.8 ft-lb). CAUTION: Do not tighten excessively, or oil may leak. Be careful not to use the oil filter 80 mm (3.15 in) in diameter to Turbo model.
36. Install the water bypass pipe between oil cooler and water pump.
37. Install the water pipe. NOTE: Always use a new O-ring.
38. Install the cylinder head. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Cylinder Head. >
39. Install the oil level gauge guide and tighten the attaching bolt (LH side).
40. Install the rocker cover and rocker cover gasket. NOTE: Use a new rocker cover gasket.
41. Install the crank sprocket. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Sprocket. >
42. Install the cam sprocket. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Cam Sprocket. >
43. Install the timing belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt. >
44. Install the timing belt cover. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Timing Belt Cover. >
45. Install the crank pulley. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), Crank Pulley. >
46. Install the generator and A/C compressor brackets on cylinder head.
47. Install the V-belt. < Ref. to «INSTALLATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), V-belt. >
48. Install the intake manifold. < Ref. to «REMOVAL»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/fuel-system/#fuel-injection-fuel-systems-h4dotc), Intake Manifold. >

Scheme 449

1. Remove the connecting rod cap.
2. Remove the connecting rod bearing. NOTE: 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. NOTE: Arrange the removed piston rings in proper order to prevent confusion.
5. Remove the snap ring.

Scheme 450

1. Apply oil to the surfaces of the connecting rod bearings. Install the connecting rod bearings on connecting rods and connecting rod caps.
2. Install the connecting rod on crankshaft. NOTE: Position each connecting rod with the side marked facing forward.
3. Tighten the connecting rod cap with connecting rod bolt. Ensure the arrow on connecting rod cap faces the front during installation. Tightening torque: 52 N.m (5.3 kgf-m, 38.4 ft-lb) CAUTION: Each connecting rod has its own mating cap. Make sure that they are assembled correctly by checking their matching number. When tightening the connecting rod bolts, apply oil on the threads.
4. Install the oil ring upper rail, expander and lower rail in this order by hand. Then install the second ring and top ring using a piston ring expander.

CYLINDER BLOCK

1. Visually check for cracks and damage. Especially, inspect the important parts by means of liquid penetrant tester.
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: 0.025 mm (0.00098 in) Grinding limit: 0.1 mm (0.004 in) Standard height of cylinder block: 201.0 mm (7.91 in)

Scheme 451

Scheme 452

Scheme 453

1. The cylinder bore size is stamped on cylinder block's front upper surface. NOTE: Measurement should be performed at a temperature of 20°C (68°F). 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: 99.505 - 99.515 mm (3.9175 - 3.9779 in) B: 99.495 - 99.505 mm (3.9171 - 3.9175 in) (Scheme 433): Identifying Cylinder Bore Size Is Stamped On Cylinder Block'S Front Upper Surface
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. NOTE: 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) (Scheme 434): Measuring Inner Diameter Of Cylinder Bore
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) NOTE: Measurement should be performed at a temperature of 20°C (68°F). Piston grade point H: 38.2 mm (1.50 in) Piston outer diameter: Standard A: 99.505 - 99.515 mm (3.9175 - 3.9179 in) B: 99.495 - 99.505 mm (3.9171 - 3.9175 in) 0.25 mm (0.0098 in) oversize 99.745 - 99.765 mm (3.9270 - 3.9278 in) 0.50 mm (0.0197 in) oversize 99.995 - 100.015 mm (3.9368 - 3.9376 in) (Scheme 435): Measuring Outer Diameter Of Piston
5. Calculate the clearance between cylinder and piston. NOTE: Measurement should be performed at a temperature of 20°C (68°F). Cylinder to piston clearance at 20°C (68°F): Standard -0.010 - 0.010 mm (-0.0004 - 0.0004 in) Limit 0.030 mm (0.0012 in)
6. Boring and honing If the value of taper, out-of-roundness, or cylinder-to-piston clearance measured exceeds the limit or if there is any damage on the cylinder wall, reboring 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 crank-case. NOTE: 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. Cylinder enlarging (boring) limit (dia.): To 100.005 mm (3.937 In)

Scheme 454

Scheme 455

Scheme 456

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. < Ref. to «CYLINDER AND PISTON»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc), INSPECTION, Cylinder Block. > If any of the clearances is not within specification, replace the piston or bore the cylinder to use an oversize piston.
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) (Scheme 436): Measuring Inner Diameter Piston (Scheme 437): Measuring Outer Diameter Piston Pin
4. Check the snap ring installation groove (A) on piston for burr. If necessary, remove the burr from groove so that the piston pin can lightly move. (Scheme 438): Identifying Snap Ring Installation Position
5. Check the piston pin snap ring for distortion, cracks and wear.

Scheme 457

Scheme 458

Scheme 459

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. CAUTION: Marks are shown on the end of top and second rings. When installing the rings to piston, face this mark upward. Oil ring consists of upper rail, expander and lower rail. When installing on piston, be careful of each rail's direction. (Scheme 439): Identifying Upper Rail, Expander And Lower Rail Gap Position
2. Squarely place the piston ring and oil ring in cylinder, and then measure the piston ring closed gap with a thickness gauge. PISTON RING CLEARANCE Unit: mm (in) Standard Limit Piston ring closed gap Top ring 0.20 - 0.25 (0.0079 - 0.0098) 1.0 (0.039) Second ring 0.37 - 0.52 (0.015 - 0.020) 1.0 (0.039) Oil ring rail 0.20 - 0.50 (0.0079 - 0.0197) 1.5 (0.059) see scheme 198: Measuring Piston Ring Closed Gap
3. Measure the clearance between piston ring and piston ring groove with a thickness gauge. NOTE: Before measuring the clearance, clean the piston ring groove and piston ring. PISTON RING CLEARANCE Unit: mm (in) Standard Limit Clearance between piston ring and piston ring groove Top ring 0.040 - 0.080 (0.0016 - 0.0031) 0.15 (0.0059) Second ring 0.030 - 0.070 (0.0012 - 0.0028) 0.15 (0.0059) (Scheme 440): Measuring Clearance Between Piston Ring And Piston Ring Groove

Scheme 460

Scheme 461

Scheme 462

Scheme 463

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) (Scheme 441): Checking For Bend Or Twist
3. Install the connecting rod fitted with bearing to crankshaft, and then 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) (Scheme 442): Measuring Connecting Rod Side Clearance
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 the specification, replace the defective bearing with a new one of standard size or undersize as necessary. (See the «BEARING SPECIFICATION»(/subaru/impreza-wrx/gdgg-2-2005-2007/remont/mechanical/#engine-mechanical-h4dotc) below.) Connecting rod oil clearance: Standard 0.017 - 0.045 mm (0.0007 - 0.0018 in) Limit 0.05 mm (0.0020 in) BEARING SPECIFICATIONS Unit: mm (in) Bearing Bearing size (Thickness at center) Outer diameter of crank pin Standard 1.490 - 1.502 (0.0587 - 0.0591) 51.984 - 52.000 (2.0466 - 2.0472) 0.03 (0.0012) undersize 1.504 - 1.512 (0.0592 - 0.0595) 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 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) (Scheme 443): Measuring Piston Pin Clearance At Connecting Rod Small End (Scheme 444): Measuring Outer Diameter Piston Pin
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 (Scheme 445): Pressing Bushing With Connecting Rod Bushing Remover And Installer ST 499037100 Make two 3 mm (0.12 in) holes in bushing. Ream the inside of bushing. After the completion of reaming, clean the bushing to remove chips.

Scheme 464

Scheme 465

Scheme 466

1. Clean the crankshaft completely and check for cracks by means of liquid penetrant tester etc., and replace if defective.
2. Measure the crankshaft bend, and correct or replace if it exceeds the limit. NOTE: If a suitable V-block is not available, install the #1 and #5 crankshaft bearing on cylinder block, position the crankshaft on these bearings and measure the crankshaft bend using a dial gauge. Crankshaft bend limit: 0.035 mm (0.0014 in) (Scheme 446): Measuring Crankshaft Runout
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 then replace or recondition the crankshaft as necessary. When grinding the crank journal or crank pin, finish them to specified dimensions according to the undersize bearing to be used. Crank pin: Out-of-roundness 0.003 mm (0.0001 in) Cylindrically 0.004 mm (0.0002 in) Grinding limit To 51.750 mm (2.0374 in) dia. Crank journal: Out-of-roundness 0.005 mm (0.0002 in) Cylindrically 0.006 mm (0.0002 in) Grinding limit To 59.750 mm (2.3524 in) dia. (Scheme 447): Inspecting Crank Journal And Crank Pin For Wear CRANK JOURNAL DIAMETER Unit: mm (in) Crank journal diameter Crank pin diameter #1, #3 #2, #4, #5 Standard Journal O.D. 59.992 - 60.008 (2.3619 - 2.3625) 59.992 - 60.008 (2.3619 - 2.3625) 51.984 - 52.000 (2.0466 - 2.0472) Bearing size (Thickness at center) 1.998 - 2.011 (0.0787 - 0.0792) 2.000 - 2.013 (0.0787 - 0.0793) 1.490 - 1.502 (0.0587 - 0.0591) 0.03(0.0012) undersize Journal O.D. 59.962 - 59.978 (2.3607 - 2.3613) 59.962 - 59.978 (2.3607 - 2.3613) 51.954 - 51.970 (2.0454 - 2.0461) Bearing size (Thickness at center) 2.017 - 2.020 (0.0794 - 0.0795) 2.019 - 2.022 (0.0795 - 0.0796) 1.504 - 1.512 (0.0592 - 0.0595) 0.05 (0.0020) undersize Journal O.D. 59.942 - 59.958 (2.3599 - 2.3605) 59.942 - 59.958 (2.3599 - 2.3605) 51.934 - 51.950 (2.0447 - 2.0453) Bearing size (Thickness at center) 2.027 - 2.030 (0.0798 - 0.0799) 2.029 - 2.032 (0.0799 - 0.0800) 1.514-1.522 (0.0596 - 0.0599) 0.25 (0.0098) undersize Journal O.D. 59.742 - 59.758 (2.3520 - 2.3527) 59.742 - 59.758 (2.3520 - 2.3527) 51.734 - 51.750 (2.0368 - 2.0374) Bearing size (Thickness at center) 2.127 - 2.130 (0.0837 - 0.0839) 2.129 - 2.132 (0.0838 - 0.0839) 1.614 - 1.622 (0.0635 - 0.0639) O.D.: Outer Diameter
4. Measure the side clearance of crankshaft at center bearing. If the clearance exceeds the limit, replace the bearing. Crankshaft side clearance: Standard 0.030 - 0.115 mm (0.0012 - 0.0045 in) Limit 0.25 mm (0.0098 in) (Scheme 448): Measuring Side Clearance Of Crankshaft Center Bearing
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. Crankshaft oil clearance: Standard 0.010 - 0.030 mm (0.0004 - 0.0012 in) Limit 0.040 mm (0.0016 in)

For operations related to intake and exhaust valve, refer to "Cylinder Head".

< Ref. to REMOVAL , Cylinder Head. > < Ref. to INSTALLATION , Cylinder Head. >

For operations related to piston, refer to "Cylinder Block".

< Ref. to REMOVAL , Cylinder Block. > < Ref. to INSTALLATION , Cylinder Block. >

For operations related to connecting rod, refer to "Cylinder Block".

< Ref. to REMOVAL , Cylinder Block. > < Ref. to INSTALLATION , Cylinder Block. >

For operations related to crankshaft, refer to "Cylinder Block".

< Ref. to REMOVAL , Cylinder Block. > < Ref. to INSTALLATION , Cylinder Block. >

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

TROUBLESHOOTING CHART

TROUBLESHOOTING CHART

Note. When disconnecting the fuel injector connector, the malfunction indicator light illuminates and DTC is stored in ECM memory. Therefore, carry out the clear memory mode < Ref. to OPERATION , Clear Memory Mode. > and inspection mode < Ref. to PROCEDURE , Inspection Mode. > after connecting the fuel injector connector.

See also:
• RELEASING OF FUEL PRESSURE
• REMOVAL
• BASIC DIAGNOSTIC PROCEDURE
• REMOVAL
• REMOVAL
• REMOVAL
• REFRIGERANT RECOVERY PROCEDURE
• REMOVAL
• REMOVAL
• REMOVAL
• REMOVAL
• REMOVAL
• INSTALLATION
• REMOVAL
• INSTALLATION
• ADJUSTMENT
• INSPECTION
• FRONT SIDE BELT
• REMOVAL