diff SUBARU LEGACY 1999 Service Repair Manual

CAUTION:
Never rotate idle adjusting screw. If idle speed
is out of specifications, refer to General On-
board Diagnosis Table under ª2-7 On-Board
Diagnostics II Systemº.
4. Engine Compression
A: MEASUREMENT
1. 2200 cc MODEL
1) After warming-up the engine, turn ignition
switch to OFF.
2) Make sure that the battery is fully charged.
3) Remove all the spark plugs.
4) Disconnect connectors from fuel injectors.
5) Fully open throttle valve.
6) Check the starter motor for satisfactory perfor-
mance and operation.
7) Hold the compression gauge tight against the
spark plug hole.
CAUTION:
When using a screw-in type compression
gauge, the screw (put into cylinder head spark
plug hole) should be less than 18 mm (0.71 in)
long.
8) Crank the engine by means of the starter motor,
and read the maximum value on the gauge when
the pointer is steady.
G2M0098
9) Perform at least two measurements per
cylinder, and make sure that the values are correct.
Compression (200 Ð 300 rpm and fully open
throttle):
Standard;
1,079 Ð 1,275 kPa (11.0 Ð 13.0 kg/cm
2,
156 Ð 185 psi)
Limit;
883 kPa (9.0 kg/cm
2, 128 psi)
Difference between cylinders;
196 kPa (2.0 kg/cm
2, 28 psi)
4
2-2[W4A1]SERVICE PROCEDURE
4. Engine Compression

CAUTION:
Never rotate idle adjusting screw. If idle speed
is out of specifications, refer to General On-
board Diagnosis Table under ª2-7 On-Board
Diagnostics II Systemº.
4. Engine Compression
A: MEASUREMENT
1. 2200 cc MODEL
1) After warming-up the engine, turn ignition
switch to OFF.
2) Make sure that the battery is fully charged.
3) Remove all the spark plugs.
4) Disconnect connectors from fuel injectors.
5) Fully open throttle valve.
6) Check the starter motor for satisfactory perfor-
mance and operation.
7) Hold the compression gauge tight against the
spark plug hole.
CAUTION:
When using a screw-in type compression
gauge, the screw (put into cylinder head spark
plug hole) should be less than 18 mm (0.71 in)
long.
8) Crank the engine by means of the starter motor,
and read the maximum value on the gauge when
the pointer is steady.
G2M0098
9) Perform at least two measurements per
cylinder, and make sure that the values are correct.
Compression (200 Ð 300 rpm and fully open
throttle):
Standard;
1,079 Ð 1,275 kPa (11.0 Ð 13.0 kg/cm
2,
156 Ð 185 psi)
Limit;
883 kPa (9.0 kg/cm
2, 128 psi)
Difference between cylinders;
196 kPa (2.0 kg/cm
2, 28 psi)
4
2-2[W4A1]SERVICE PROCEDURE
4. Engine Compression

2. 2500 cc MODEL
CAUTION:
After warming-up, engine becomes very hot.
Be careful not to burn yourself during mea-
surement.
1) After warming-up the engine, turn ignition
switch to OFF.
2) Make sure that the battery is fully charged.
3) Remove all the spark plugs. [W3B0].>
4) Disconnect connectors from fuel injectors.
5) Fully open throttle valve.
6) Check the starter motor for satisfactory perfor-
mance and operation.
7) Hold the compression gauge tight against the
spark plug hole.
CAUTION:
When using a screw-in type compression
gauge, the screw (put into cylinder head spark
plug hole) should be less than 18 mm (0.71 in)
long.
8) Crank the engine by means of the starter motor,
and read the maximum value on the gauge when
the pointer is steady.
B2M0752A
9) Perform at least two measurements per
cylinder, and make sure that the values are correct.
Compression (350 rpm and fully open
throttle):
Standard;
1,216 kPa (12.4 kg/cm
2, 176 psi)
Limit;
941 kPa (9.6 kg/cm
2, 137 psi)
Difference between cylinders;
49 kPa (0.5 kg/cm
2, 7 psi), or less
5. Intake Manifold Vacuum
A: MEASUREMENT
1) Warm-up the engine.
2) Disconnect the brake vacuum hose and install
the vacuum gauge to the hose fitting on the mani-
fold.
3) Keep the engine at the idle speed and read the
vacuum gauge indication.
By observing the gauge needle movement, the
internal condition of the engine can be diagnosed
as described below.
H2M1601
Vacuum pressure (at idling, A/C ªOFFº):
Less than þ60.0 kPa (þ450 mmHg, þ17.72
inHg)
5
[W5A0]2-2SERVICE PROCEDURE
5. Intake Manifold Vacuum

2. 2500 cc MODEL
CAUTION:
After warming-up, engine becomes very hot.
Be careful not to burn yourself during mea-
surement.
1) After warming-up the engine, turn ignition
switch to OFF.
2) Make sure that the battery is fully charged.
3) Remove all the spark plugs. [W3B0].>
4) Disconnect connectors from fuel injectors.
5) Fully open throttle valve.
6) Check the starter motor for satisfactory perfor-
mance and operation.
7) Hold the compression gauge tight against the
spark plug hole.
CAUTION:
When using a screw-in type compression
gauge, the screw (put into cylinder head spark
plug hole) should be less than 18 mm (0.71 in)
long.
8) Crank the engine by means of the starter motor,
and read the maximum value on the gauge when
the pointer is steady.
B2M0752A
9) Perform at least two measurements per
cylinder, and make sure that the values are correct.
Compression (350 rpm and fully open
throttle):
Standard;
1,216 kPa (12.4 kg/cm
2, 176 psi)
Limit;
941 kPa (9.6 kg/cm
2, 137 psi)
Difference between cylinders;
49 kPa (0.5 kg/cm
2, 7 psi), or less
5. Intake Manifold Vacuum
A: MEASUREMENT
1) Warm-up the engine.
2) Disconnect the brake vacuum hose and install
the vacuum gauge to the hose fitting on the mani-
fold.
3) Keep the engine at the idle speed and read the
vacuum gauge indication.
By observing the gauge needle movement, the
internal condition of the engine can be diagnosed
as described below.
H2M1601
Vacuum pressure (at idling, A/C ªOFFº):
Less than þ60.0 kPa (þ450 mmHg, þ17.72
inHg)
5
[W5A0]2-2SERVICE PROCEDURE
5. Intake Manifold Vacuum

C: INSPECTION
1. VALVE ROCKER ARM
1) Measure inside diameter of valve rocker arm
and outside diameter of valve rocker shaft, and
determine the difference between the two (= oil
clearance).
Clearance between arm and shaft:
Standard
0.020 Ð 0.054 mm (0.0008 Ð 0.0021 in)
Limit
0.10 mm (0.0039 in)
IIf oil clearance exceeds specifications, replace
valve rocker arm or shaft.
NOTE:
Replace valve rocker arm or shaft, whichever
shows greater amount of wear.
Rocker arm inside diameter:
22.020 Ð 22.041 mm (0.8669 Ð 0.8678 in)
Rocker shaft diameter:
21.987 Ð 22.000 mm (0.8656 Ð 0.8661 in)
B2M0072
B2M0073
2) Measure inside diameter of rocker shaft sup-
port and outside diameter of valve rocker shaft,
and determine the difference between the two (=
oil clearance).
Clearance between support and shaft:
Standard
0.005 Ð 0.039 mm (0.0002 Ð 0.0015 in)
Limit
0.05 mm (0.0020 in)
IIf oil clearance exceeds specifications, replace
rocker shaft support or shaft.
NOTE:
Replace rocker shaft support or shaft, whichever
shows greater amount of wear.
Rocker shaft support inside diameter:
22.005 Ð 22.026 mm (0.8663 Ð 0.8672 in)
Rocker shaft diameter:
21.987 Ð 22.000 mm (0.8656 Ð 0.8661 in)
3) If cam or valve contact surface of valve rocker
arm is worn or dented excessively, replace valve
rocker arm.
4) Check that valve rocker arm roller rotates
smoothly. If not, replace valve rocker arm.
2. INTAKE AND EXHAUST VALVE
ROCKER SHAFT
Visually check oil relief valve of shaft end for any
of the following abnormalities.
IBreaks in check ball body
IForeign particles caught in valve spring
IOil leakage at check ball
CAUTION:
Repair or replace valve rocker shaft as neces-
sary.
29
[W3C2]2-3aSERVICE PROCEDURE
3. Valve Rocker Assembly

3) Measure outside diameter of camshaft journal
and inside diameter of cylinder head journal, and
determine the difference between the two (= oilclearance). If oil clearance exceeds specifications,
replace camshaft or cylinder head as necessary.
Unit: mm (in)
Clearance at journalStandard 0.055 Ð 0.090 (0.0022 Ð 0.0035)
Limit 0.118 (0.0046)
Camshaft journal O.D. 31.928 Ð 31.945 (1.2570 Ð 1.2577)
Journal hole I.D. 32.000 Ð 32.018 (1.2598 Ð 1.2605)
4) Check cam face condition; remove minor faults
by grinding with oil stone. Measure the cam height
H; replace if the limit has been exceeded.
Cam height: H
Unit: mm (in)
Item Standard Limit
Intake34.00 Ð 38.782
(1.3386 Ð 1.5268)33.84 (1.3323)
Exhaust34.00 Ð 39.307
(1.3386 Ð 1.5475)33.84 (1.3323)
Cam base circle diameter A:
IN: 27.5 mm (1.083 in)
EX: 27.0 mm (1.063 in)
B2M1209A
2. CAMSHAFT SUPPORT
Measure the thrust clearance of camshaft with dial
gauge. If the clearance exceeds the limit, replace
camshaft support.
Standard:
0.030 Ð 0.090 mm (0.0012 Ð 0.0035 in)
Limit:
0.11 mm (0.0043 in)
B2M2618A
35
[W4B2]2-3aSERVICE PROCEDURE
4. Camshaft

6. INTAKE AND EXHAUST VALVE OIL
SEAL
Replace oil seal with new one, if lip is damaged or
spring out of place, or when the surfaces of intake
valve and valve seat are reconditioned or intake
valve guide is replaced.
1) Place cylinder head on ST1.
2) Press-fit oil seal to the specified dimension indi-
cated in the figure using ST2.
CAUTION:
IApply engine oil to oil seal before press-fit-
ting.
IWhen press-fitting oil seal, do not use ham-
mer or strike in.
IDifferentiate between intake valve oil seal
and exhaust valve oil seal by noting their dif-
ference in color.
ST1 498267800 CYLINDER HEAD TABLE
ST2 498857100 VALVE OIL SEAL GUIDE
Color of rubber part:
Intake [Black]
Exhaust [Brown]
Color of spring part:
Intake [Silver]
Exhaust [Silver]
B2M2633A
47
[W5C6]2-3aSERVICE PROCEDURE
5. Cylinder Head

4) How to measure the outer diameter of each
piston
Measure the outer diameter of each piston at the
height shown in the figure. (Thrust direction)
CAUTION:
Measurement should be performed at a tem-
perature of 20ÉC (68ÉF).
Piston grade point H:
40.0 mm (1.575 in)
Piston outer diameter:
Standard
A: 96.885 Ð 96.895 mm (3.8144 Ð 3.8148
in)
B: 96.875 Ð 96.885 mm (3.8140 Ð 3.8144
in)
0.25 mm (0.0098 in) oversize
97.125 Ð 97.135 mm (3.8238 Ð 3.8242 in)
0.50 mm (0.0197 in) oversize
97.375 Ð 97.385 mm (3.8337 Ð 3.8340 in)
B2M1305A
5) Calculate the clearance between cylinder and
piston.
CAUTION:
Measurement should be performed at a tem-
perature of 20ÉC (68ÉF).
Cylinder to piston clearance at 20ÉC (68ÉF):
Standard
0.010 Ð 0.030 mm (0.0004 Ð 0.0012 in)
Limit
0.050 mm (0.0020 in)
6) Boring and honing
(1) If the value of taper, out-of-roundness, or
cylinder- to-piston clearance measured exceeds
the specified limit or if there is any damage on
the cylinder wall, rebore it to use an oversize
piston.
CAUTION:
When any of the cylinders needs reboring, all
other cylinders must be bored at the same
time, and use oversize pistons. Do not perform
boring on one cylinder only, nor use an over-
size piston for one cylinder only.(2) If the cylinder inner diameter exceeds the
limit after boring and honing, replace the crank-
case.
CAUTION:
Immediately after reboring, the cylinder diam-
eter may differ from its real diameter due to
temperature rise. Thus, pay attention to this
when measuring the cylinder diameter.
Limit of cylinder enlarging (boring):
0.5 mm (0.020 in)
3. PISTON AND PISTON PIN
1) Check 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. If any of the
clearances is not to specification, replace the pis-
ton or bore the cylinder to use an oversize piston.
3) Make sure that piston pin can be inserted into
the piston pin hole with a thumb at 20ÉC (68ÉF).
Replace if defective.
Standard clearance between piston pin and
hole in piston:
Standard
0.004 Ð 0.008 mm (0.0002 Ð 0.0003 in)
Limit
0.020 mm (0.0008 in)
B2M1401
B2M0084A
58
2-3a[W6C3]SERVICE PROCEDURE
6. Cylinder Block

5. VALVE SPRINGS
1) Check valve springs for damage, free length,
and tension. Replace valve spring if it is not to the
specifications presented in the table.
2) To measure the squareness of the valve spring,
stand the spring on a surface plate and measure
its deflection at the top using a try square.
Valve spring
Free length 39.8 mm (1.567 in)
Tension/spring height228.5 Ð 261.8 N
(23.3 Ð 26.7 kg, 51.4 Ð 58.9
lb)/31.0 mm (1.220 in)
462.9 Ð 531.5 N
(47.2 Ð 54.2 kg, 104.1 Ð 119.5
lb)/23.2 mm (0.913 in)
Squareness 2.5É, 1.7 mm (0.067 in)
G2M0154
6. INTAKE AND EXHAUST VALVE OIL
SEAL
Replace oil seal with new one, if lip is damaged or
spring out of place, or when the surfaces of intake
valve and valve seat are reconditioned or intake
valve guide is replaced.
1) Place cylinder head on ST1.
2) Press in oil seal to the specified dimension indi-
cated in the figure by using ST2.
ST1 498267600 CYLINDER HEAD TABLE
ST2 498857100 VALVE OIL SEAL GUIDE
CAUTION:
IApply engine oil to oil seal before force-fit-
ting.
IDifferentiate between intake valve oil seal
and exhaust valve oil seal by noting their dif-
ference in color.
Color of rubber part:
Intake [Black]
Exhaust [Brown]
Color of spring part:
Intake [Silver]
Exhaust [Silver]
B2M1399A
7. VALVE LIFTER
1) Check valve lifter visually.
2) Measure outer diameter of valve lifter.
Outer diameter:
32.959 Ð 32.975 mm (1.2976 Ð 1.2982 in)
B2M1222
41
[W4C7]2-3bSERVICE PROCEDURE
4. Cylinder Head

3) Measure inner diameter of valve lifter mating
part on cylinder head.
Inner diameter:
32.994 Ð 33.016 mm (1.2990 Ð 1.2998 in)
B2M1400
CAUTION:
If difference between outer diameter of valve
lifter and inner diameter of valve lifter mating
part is over the limit, replace cylinder head.
Standard:
0.019 Ð 0.057 mm (0.0007 Ð 0.0022 in)
Limit:
0.100 mm (0.0039 in)
D: ASSEMBLY
S2M0420A
(1) Valve shim
(2) Valve lifter
(3) Valve retainer key(4) Valve retainer
(5) Valve spring
(6) Valve oil seal(7) Valve spring seat
(8) Intake valve
(9) Exhaust valve
42
2-3b[W4D0]SERVICE PROCEDURE
4. Cylinder Head