H-4H-4 andand H-6H-6 EngineEngine ServiceService

The used in all Subaru mod- reshaped and the overall weight has els have received major changes and been reduced by approximately 100 upgrades in the past few years, and grams. has been some completely new engines have increased to 9.7 to 1 by reshaping the also been introduced. We’ll explain the crown of the . This eliminates the changes, especially as they relate to clearance that was available between the your vehicle service efforts. piston at TDC and a fully opened valve. Piston pin offset has been changed to 2.2 Liter Phase 1 0.5 mm. Piston to wall clear- Enhancements ance has been reduced by increasing the The 2.2 liter Phase 1 engine has been piston diameter. enhanced, starting with 1997 model Another source of engine friction is year. The single overhead the . Hydraulic lash adjusters (SOHC) engines have had internal and are always in contact with the camshaft external changes that yield an approxi- or valve rockers. The hydraulic pres- mately 10% increase in power and 3% sure of the lash adjuster must be over- increase in fuel economy. come during operation and engine Accomplishing this involves many fac- starting. To overcome this situation and tors, one of which is engine friction to contribute to the total reduction of reduction. friction loss, the SOHC engines have The piston, a major source of engine solid valve adjusters. friction, has been coated with a friction The scheduled service of these valve- reducing agent called molybdenum. trains is set at 100,000 miles. The This thin coating not only allows a SOHC engine uses an adjustment smoother travel through the cylinder screw and locknut. Follow the instruc- ® but also reduces cylinder wall scuffing. tions below for setup and adjustment. This coating will wear off over time Tools required for 2.2 valve adjustment and is not an indication of a problem. are: thickness gauge, 10mm wrench, The skirt of the piston has been stubby standard screwdriver, crank-

The

www.endwrench.com www.endwrench.com End Wrench 4 shaft wrench. follows: Step 1 • The engine and transmission are fastened with six Remove the right bank camshaft outer cover. bolts and two studs. Standard value clearance: • The thrust bearing has been moved to the number Intake valves 0.20 ± 0.02 mm 5 position. Exhaust valves 0.25 ± 0.02 mm. • The oil groove in the number 1 and 3 have been changed to supply additional lubrication to the Rotate the engine until the arrow on the camshaft crank journal. sprocket is at 12:00. The camshaft sprocket has an arrow and a mark for belt timing. Make certain the Additional Phase 2 Engine Features arrow is used, not the mark for valve adjustment only. • The is a two-rocker shaft, solid type Using a standard thickness gauge, measure the valve system with roller followers. clearance of the intake and exhaust valves on cylin- • The valves are positioned at a larger angle than der 1 only. Adjust the clearance by loosening the previous model years. The intake valves are posi- locknut and turning the adjustment screw until the tioned 23 degrees off-center with the exhaust valves proper clearance is obtained. positioned 20 degrees off-center. Prior model year engines utilized a 15-degree positioning angle.

• thickness is 0.7 mm.

Adjusting Valve Clearance Identification of Rocker Arms Step 2 Rotate the engine until the arrow on the camshaft • The intake rocker arms are marked so they are cor- sprocket is at 3:00. Check and adjust the clearance of rectly placed on the rocker shaft when servicing. An the intake and exhaust valves on cylinder 3 only. IN1 or IN2 will be embossed on each . As viewed from the front of the engine the Number 1 Step 3 intake valve of each cylinder and the number 2 Rotate the engine until the arrow on the camshaft intake valve have an IN1 marked and IN2 marked sprocket is at 6:00. Check and adjust the clearance of rocker arm that mates with it. New IN1 rocker arms the intake and exhaust valves on cylinder 2 only. can also be identified by a Green painted mark on the top of the rocker arm. The IN2 rocker arms have Other Engine Modifications a white mark. Proper positioning is maintained The intake manifold has been reshaped to increase through the use of a wave washer located between the airflow mass and speed, contributing to the rocker shaft arm and rocker arm shaft support. improved low and mid engine speed operation. • The camshaft is secured to the cylinder head with Components located on the intake manifold have the camcase. An oil passage in the cylinder head been relocated as compared to the 1996 models. EGR provides the passageway in the camcase with oil Solenoid, Purge Control Solenoid, etc. that leads to the intake rocker shaft. Oil from the camshaft is collected on the opposite side of the pas- 1999 2.2 Liter Phase 2 Engine Enhancements sageway leading to the intake rocker shaft to provide All 2.2 liter engine for 1999 are the Phase 2 oil to the exhaust rocker shaft. design. The 2.2 liter Phase 2 engines are a SOHC • Sealing of the camcase is accomplished by using a design, with a newly-designed cylinder head. thin layer of Three Bond (1280B) applied in the Changes in the 2.2 liter Phase 2 engines are as channel around the camcase edge. After the three Continued on page 8.

5 H-4 and H-6 Engine Service

bond is applied, the camcase must be timing mark on the exhaust camshaft installed to the cylinder head and onto sprocket, positioned at the 3 o’clock, the engine before the three bond has ensures the exhaust camshaft sprocket is time to cure. Failure to do this will timed correctly to the engine. With all result in oil leaks. timing marks aligned, the intake and exhaust camshaft are in a loaded state. If Note: Cylinder head and camcase must the were removed, the be replaced together (line bored). would suddenly revolve from the force of the valve springs. To prevent • The sparkplug pipe is pressed into this from occurring maintain the intake the cylinder head and is not service- camshaft position and carefully unload able. If it becomes damaged the cylin- the camshaft by allowing it to slowly der head must be replaced. The seals rotate counterclockwise, (exhaust clock- installed onto the ends of the sparkplug wise) while removing the belt. pipes seal against the valve covers and should be replaced when the valve Note: Use special tool J-42908 for hold- cover is removed. ing camshaft sprockets during belt • Timing belt marks for the left bank installation. It may also be used for are on the inner timing belt cover and loading as well as unloading the the edge of the camshaft sprocket. The camshafts. Caution: valve damage will timing mark remains on the occur if both camshafts are turned reluctor with mark, just incorrectly after the timing belt has below the crank angle sensor. The been removed. right bank camshaft sprocket has a mark at the edge that is matched with the seam line formed by the meeting of the camcase and cylinder head (12:00 position). • The right bank timing mark can be checked with outer cover in place using the provided window. • on the 2.2 liter engines have a 0.5 mm offset with the engine having a compression ratio of 10.0 to 1. The horsepower has increased to 142 hp @ 5600 RPM. Maximum torque is149 ft. lbs @ 3600 RPM. Camshaft Sprocket Timing Marks (Right Bank) • The 2.5 liter engine uses double over- head camshafts that are belt-driven. Belt tension is maintained through the • The right bank intake sprockets tim- use of the hydraulic tensioner which is ing marks are similar in location and also used on the 2.2 and 3.3 liter purpose to the left bank. However, the engine. exhaust camshaft sprocket on the right • Camshaft sprockets are constructed of a bank uses a timing mark at the 9:00 resin type material with a metal key o’clock position to ensure proper pressed into the sprocket for maintaining camshaft to engine timing. proper sprocket to shaft orientation. • To access the cylinder head bolts, the camshafts must be removed. Follow the The timing marks on the left bank procedure outlined in the Subaru serv- intake camshaft sprocket are positioned ice manual for performing this task. at 12 o’clock and 6 o’clock. The 12 The camshafts are held to the cylinder o’clock mark, which aligns with a tim- head with bearing caps that are ing mark on the timing belt housing, is marked (right side) I1TD, I3TD, E1TD, used for camshaft to engine timing. The E3TD. ® 6 o’clock mark is used for timing the • 2.5 liter engine head gaskets are iden- intake camshaft to the exhaust tified by the three notches located camshaft, which has a timing mark at along the gaskets edge, 2.2 liter normal- the 12 o’clock positions. The remaining ly aspirated engine head gaskets have

The

www.endwrench.com www.endwrench.com End Wrench 8 only two notches. requires no servicing. socket. Caution: The bolt patterns for • Spark plugs for the 2.5 liter 2. Tighten the in the both gaskets are the same but are engine are platinum tipped, NGK cylinder head with the socket. It not interchangeable. PFR5B-11. (Same maintenance is necessary to support the end of schedule as the SVX.) 2.2 liter the socket by a finger. • The cylinder head bolts for the engines use Champion RC10YC4. 3. When the spark plug can be felt 2.5 liter engine are much shorter • Engine oil viscosity for all ‘96 to be tightened with 2 or 3 rota- than those of the 2.2 liter engine, Legacy and Outback vehicles is tions, remove the socket from the and are not interchangeable. 5W-30 to improve fuel economy. spark plug. • Valve servicing is accomplished by utilizing special tool 2.5 Liter Engine Spark Plug 499718000 and a universal valve Replacement Procedure spring compressor. The single 1. Remove battery, washer tank valve spring is color coded red and air cleaner. and rests on a metal spring seat 2. Remove high tension cords. which is used to prevent cylinder 3. Cover ATF pipes and ABS head wear . A special tool pipes with cloth to prevent them (498267700) is required to adjust from damage during replacement valve guide height, if replacement of spark plugs. is necessary. A valve guide reamer 4. Remove spark plugs by using a Spark Plug Removal (499767400) and a valve guide general service tool with the spe- remover (499767200) will also cial instruction described below. 4. Confirm if the spark plug is have to be used. The hydraulic screwed into the hole properly by lash adjuster is of the same type Installation touching it with a finger. If it is as the 3.3 liter engine and 1. Set the spark plug into the difficult to touch it by finger, con-

9 H-4 and H-6 Engine Service

firm its condition by using mirror. possible by performing the following: 5. Reset the socket on the plug then Step 1 tighten it with the proper torque. • Set the crankshaft sprocket at 0 6. Install high tension cords. degrees. (use crankshaft wrench) 7. Install battery, washer tank, and air • Set the left intake camshaft sprocket cleaner. arrow at 12 o’clock. The camshaft sprocket has an arrow and a mark used Note: Length L1 (100mm, 3.94”) is most for belt timing. Make certain to use the important for ease of removal and arrow and not the mark for valve clear- installation. Wrap points A & B with ance check. tape to prevent them from separating • The engine is now set to check the during work. An approximate 250mm clearance of the exhaust valves on extension bar is recommended between cylinders 1 and 3 only. (Please remem- the ratchet and the universal joint. ber that the profile of a camshaft with solid lifters has a ramp that is used to 1997 Phase 1 2.5 Liter gradually take up the clearance DOHC Engine between the lift of the lobe and the lash The double overhead camshaft adjuster.) engines have had internal and external • Measure and record the clearance. changes that yield an approximately 10% increase in power and 3% increase in fuel economy. Compression ratio has been increased to 9.7 to 1 by reshaping the crown of the piston. This eliminates the clear- ance that was available between the piston at TDC and a fully opened valve. Piston pin offset has been changed to 0.5 mm. Piston to cylinder wall clearance has been reduced by Cams Set for 1 and 3 Exhaust Clearance Measurement increasing the piston diameter. Another source of engine friction is the valvetrain. Hydraulic lash Step 2 adjusters are always in contact with • Rotate the crankshaft 180 degrees. the camshaft or valve rockers. The • The left intake camshaft arrow hydraulic pressure of the lash adjuster should now be at 3 o’clock. must be overcome during operation • Check the clearance of the intake and the most critical time of engine valves on cylinders 1 and 3 only. start. To contribute to friction reduc- • Record the measurement. tion, all DOHC engines have solid valve adjusters. Step 3 The scheduled service of these val- • Rotate the crankshaft 180 degrees. vetrains is set at 100,000 miles. The • The left intake camshaft arrow DOHC engine uses an adjustment should now be at 6 o’clock. shim. There are 94 shim sizes. • Check the clearance of the exhaust valves on cylinders 2 and 4 only. Note: Use a thin nonmagnetic tool • Record the measurement. placed in the notch of the lash adjuster to remove shim (special tool Step 4 J-43979). • Rotate the crankshaft 180 degrees. • The left intake camshaft sprocket Note: The printed size of the shim arrow should now be at 9:00. should be installed away from the • Check the clearance of the intake camshaft lobe. valves on cylinders 2 and 4 only. ® • Record the measurement. The space between the valvetrain and the frame rail of a DOHC is somewhat Step 5 limited, however valve adjustment is • Use the formula below to choose the

The

www.endwrench.com www.endwrench.com End Wrench 10 new shim: 2.40 mm. provided in the appropriate serv- Intake valve S = V + T - .20 T = 2.40 S = V + T (0.25 mm) ice manual for camshaft removal Exhaust valve S = V + T - .25 V = 0.19 S = .19 + 2.4 - (0.25mm) and belt installation. S = Shim thickness to be used SVC = 0.25 ± 0.03 S = 2.59 - V = Measured valve clearance 0.25mm Note: Special tool 498187100 may T = Shim thickness in use (Standard valve clearance) S = 2.34 also be used for this procedure. Standard valve clearance (Intake valves 0.20 ± 0.02 mm) The shim in use on cylinder 3 1999 2.5 Liter Engine (Exhaust valves 0.25 ± 0.02 mm) intake is marked 245.This refers Enhancements: DOHC (Phase 1) to the shim having a thickness of and SOHC (Phase 2) Example: 2.45 mm. The engines for the 1999 To solve for the new shim or T: Subaru line are designated Phase • Cylinder 1 intake measured T = 2.45 S = V + T (0.20mm) 1 and Phase 2. 2.5 liter Legacy valve or clearance is 0.22 mm - no V = 0.31 S = .31 + 2.45 - ( .20mm) engines are the Phase 1 design, adjustment needed. SVC = 0.20 ± 0.03 S = 2.76 - while the Impreza and Forester • Cylinder 1 exhaust measured .20mm utilize Phase 2 design 2.5 liter valve or clearance is 0.15 mm - (Standard valve clearance) S = engines. The 2.5 liter Phase 2 adjustment needed. 2.56 engines are SOHC engine with a • Cylinder 3 intake measured newly designed cylinder head. valve or clearance is 0.31 mm - Step 6 The (Phase 1) 2.5 liter engine uses adjustment needed. • The current method of shim the same cylinder head configura- replacement is accomplished by tion that it has used on prior year The shim in use on cylinder 1 removing the camshafts. models with the and exhaust is marked 240. This refers bell housing sharing the same to the shim having a thickness of Caution: Follow the directions characteristics of the new Phase 2

11 H-4 and H-6 Engine Service

engines. right bank camshaft sprocket has a 2.5 Liter (Phase 2) SOHC mark at the edge that is matched with Engine Features the seam line formed by the meeting of • The cylinder heads have a two-rocker the camcase and cylinder head (12:00 shaft roller solid-type valve system. position). • The valves are positioned at a larger • The right bank timing mark can be angle than previous model years. The checked with outer cover in place, intake valves are positioned 23 degrees using the provided window. off center, with the exhaust valves posi- • Piston design on the 2.5 liter engine tioned 20 degrees off center. Prior remains the same as the 2.2 liter. The model year engines utilized a 15-degree compression ratio is 9.7 to 1. positioning angle. • Head gasket thickness is 0.7 mm. 3.0 Liter Engine Features • The intake rocker arms are marked The EZ-3.0 is the model name (engine for correct installation on the rocker designation) for the new six-cylinder shaft. An IN1 or IN2 is embossed on engine introduced for the 2001 model each rocker arm. As viewed from the year Legacy. The design idea for this front of the engine, the number 1 intake engine was to create a power plant that valve of each cylinder and the number could utilize the current body style, 2 intake valve have an IN1 marked and provide more power and decreased IN2 marked rocker arm that mates with exhaust emissions. Many of the fea- it. New IN1 rocker arms can also be tures refined for the current four-cylin- identified by a green painted mark on der engine are employed on the EZ-3.0. the top of the rocker arm. The IN2 rock- However, new features such as Variable er arms have a white mark. Proper Intake Control and timing chain driven positioning is maintained through the camshafts give the new engine a look use of a wave washer located between the rocker shaft arm and rocker arm shaft support. • The camshaft is secured to the cylin- der head with the camcase. An oil pas- sage in the cylinder head provides the passageway in the camcase with oil that leads to the intake rocker shaft. Oil from the camshaft is collected on the opposite side of the passageway lead- ing to the intake rocker shaft to provide oil to the exhaust rocker shaft. • Sealing of the camcase is accom- plished by using a thin layer of Three 3.0 Liter Engine Timing Cover Bond applied in the channel around and operation all of its own. the camcase edge. After the three bond The front of the engine features a (1280B) is applied, the camcase must large front timing chain cover, secured be installed to the cylinder head and to the inner cover with 59 bolts. There onto the engine before the three bond are four different lengths used and is has time to cure. Failure to do this will sealed to the inner cover with Three result in oil leaks. Bond (1280B). Special care must be used when servicing the timing chain Note: The cylinder head and camcase covers to ensure the proper length bolt must be replaced together (line bored). and sealing procedures are used. A sin- gle serpentine belt provides the power • Timing belt marks on the left bank to turn all engine accessories. Tension are on the inner timing belt cover and to the belt is controlled with an auto- ® ® ® the edge of the camshaft sprocket. The matic tensioner. Replace the serpentine crankshaft timing mark remains on the belt when the indicator is at or beyond reluctor, with the engine block mark this line. just below the crank angle sensor. The Additional 3.0 liter engine features:

The The

www.endwrench.com www.endwrench.com www.endwrench.com End Wrench End Wrench 12 • Two radiator hose connections angle sensor and reluctor have removing the sensor. are located at the top of the been moved to the rear of the • Remove the crankshaft bolt engine block, connecting to each crankshaft. The EGR pipe has a cover, bolt and harmonic bal- of the cylinder heads. new design and is mounted on ancer. Use caution to avoid los- • An oil cooler is used to assist the left bank of the engine. ing the O-ring that seals the with bringing the oil to operating crankshaft bolt cover to the har- temperature. 3.0 Liter Engine Disassembly monic balancer. • Direct ignition coils are fitted. • Begin disassembly by unloading • Begin removing the outer cover The igniter and current control and removing the serpentine belt. bolts. Keep them organized to circuits are integrated. • Remove the fuel rail protectors ease reassembly. The bolts must • The lower hose is located on the from both sides. be removed in the proper thermostat housing, connecting to • The lower bolt must sequence to avoid warping the the lower section of the radiator. be backed out before the manifold outer case. The thermostat is housed in the oil can be removed. • The timing chain on the EZ-3.0 pan extension case. The oil pan is • Remove the alternator, compres- is designed to last the life of the much smaller than previous model sor and power steering pump. engine. Proper engine oil mainte- engines and contains a small mag- nance is necessary to ensure its net to collect metallic debris. Note: The compressor is equipped longevity. Two chains are used. • Connections for the crankcase with a speed sensor that sends a Four (4) camshaft sprockets, one ventilation system are located at signal to the ECM. If the compres- (1) crankshaft sprocket, two (2) the top of the valve cover. sor speed drops more than 20% idler sprockets and the water Pressure is equalized from the compared to the engine speed, pump complete the timing chain right bank with a cross over tube. the ECM turns the compressor off routing. • The new crank angle sensor, through the a/c relay. The refrig- • The timing chain is sprayed reluctor, and EGR pipe. The crank erant must be evacuated before with oil from a jet located on the

13 H-4 and H-6 Engine Service

oil pump relief valve housing. Caution: the sprocket teeth are sharp. Use extreme care when working around or near them.

• The right bank camshafts are in a loaded state when the keyways are at 12:00. They must be unloaded in the proper way to prevent damage to the pistons and valves. • Timing marks are located on the camshaft sprockets and the crankshaft sprocket. Marks and letters on the 3.0 Liter Engine Right Bank Timing Components idlers are manufactures markings and ing procedure. are used only to establish which side faces outward. Do not use them to Unloading Cam Sprockets establish proper chain timing. • Position the camshaft sprocket • The left bank camshaft sprockets are wrench on the right bank intake interchangeable when new. It is recom- sprocket and turn 90 degrees counter mended they be returned to their origi- clockwise. nal positions to maintain wear patterns • Position the camshaft sprocket after being used. wrench on the right bank exhaust • The left timing chain is the longer of sprocket and turn 90 degrees clock- the two with 148 links. The right chain wise. Both camshafts are now has 134 links. unloaded. • Turn engine clockwise to rotate it • Remove both the intake and exhaust until the key ways of the cam sprockets camshaft sprockets on the left and right are at the 12:00 position. Remove the banks. right bank tensioner, chain and chain • Remove the bolts from the water pump. guides. • Thread two eight millimeter bolts as • Remove the left bank tensioner, chain shown and equally turn them in. This and chain guides. will assist with the removal of the pump. Remove the O-ring that seals the Note: Turn the crankshaft 90 degrees counter clockwise to reduce the chance of accidental damage to the pistons and valves in the event the camshafts suddenly unload.

• The left bank is currently unloaded. The right bank is loaded and must be unloaded using the follow-

3.0 Liter Engine Valvetrain water pump to the inner cover. Valvetrain Construction The camshafts are composed of - bon steel pipes with sintered metal lobes. During construction, the lobes ® are positioned on the pipe using a sin- tered metal paste. The camshafts are then baked until the paste is hardened. 3.0 Liter Engine Timing Chain Routing The lobes of the camshafts are offset by

The

www.endwrench.com www.endwrench.com End Wrench 14 1 millimeter to rotate the The worm gear assemble and camshaft bucket and shim, to spring tension keep tension on reduce wear. the chains with the engine off, The right bank intake camshaft eliminating any tension problems has a reluctor built onto the end. that could occur during engine The new camshaft sensor uses this start up. The tensioners are reluctor to help determine injec- turned in by hand for reassembly. tion and . Observe the order of the worm The valve adjustment procedure gear assemble. Make sure your is the same as other DOHC Subaru hands are dry when depressing engines however a new tool has the tensioners. A rivet or large been designed to work specifically paper clip will hold tensioner in on the EZ-3.0 engine. The tool is a place. Do not use a press to wedge fitted into place over the depress the tensioner. two shims requiring removal. 3.0 Liter Engine Chain Tensioners Some adjustment will be system. The supplied pressure Oil Pan Removal required to properly seat the combined with spring tension • Remove the oil pan bolts and bucket depression finger. Turning oil pan. Observe that the oil pan the top bolt pushes the fingers keeps the timing chains operating has a different design from four down allowing room for the shim at the correct tension. cylinder Subaru engines. Note the to be removed. placement of the bolts. Note: The left bank and right • Remove the oil pan extension Chain Tensioners bank tensioners are not inter- housing bolts. There are 28 bolts The chain tensioners are fed oil changeable. with five different lengths. Follow pressure from the engine oiling the proper sequence to prevent

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