check engine SUBARU LEGACY 1996 Service Workshop Manual

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 performance
and operation.
G2M0098
7) Hold the compression gauge tight against the spark
plug hole.
CAUTION:
When using a screw-in type compression gauge, the
screw (put into cylinder head spark plug hole) should
be less than 18 mm (0.71 in) long.
8) Crank the engine by means of the starter motor, and
read the maximum value on the gauge when the pointer is
steady.
9) Perform at least two measurements per cylinder, and
make sure that the values are correct.
Compression (200—300 rpm and fully open throttle):
Standard
1,079—1,275 kPa
(11.0—13.0 kg/cm
2, 156—185 psi)
Limit
883 kPa (9.0 kg/cm
2, 128 psi)
Difference between cylinders
196 kPa (2.0 kg/cm
2, 28 psi)
2. 2500 cc MODEL
CAUTION:
After warming-up, engine becomes very hot. Be care-
ful not to burn yourself during measurement.
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. [W3E0].>
4) Disconnect connectors from fuel injectors.
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2-2
4. Engine Compression

5) Fully open throttle valve.
6) Check the starter motor for satisfactory performance
and operation.
B2M0752A
7) Hold the compression gauge tight against the spark
plug hole.
CAUTION:
When using a screw-in type compression gauge, the
screw (put into cylinder head spark plug hole) should
be less than 18 mm (0.71 in) long.
8) Crank the engine by means of the starter motor, and
read the maximum value on the gauge when the pointer is
steady.
9) Perform at least two measurements per cylinder, and
make sure that the values are correct.
Compression (350 rpm and fully open throttle):
Standard
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
2-2
4. Engine Compression

G2M0093
4) Connect oil pressure gauge hose to cylinder block.
5) Start the engine, and measure oil pressure.
Oil pressure:
98 kPa (1.0 kg/cm
2,14 psi) or more at 800 rpm
294 kPa (3.0 kg/cm2, 43 psi) or more at 5,000 rpm
CAUTION:

If oil pressure is out of specification, check oil
pump, oil filter and lubrication line.


If oil pressure warning light is turned ON and oil
pressure is in specification, replace oil pressure
switch.

NOTE:
The specified data is based on an engine oil temperature
of 80°C (176°F).
6) After measuring oil pressure, install oil pressure switch.
Tightening torque:
25±3 N⋅m (2.5±0.3 kg-m, 18.1±2.2 ft-lb)
7) Install generator and V-belt in the reverse order of
removal, and adjust the V-belt deflection.
8
2-2
6. Engine Oil Pressure

G2M0106
1. General Precautions
1) Before disassembling engine, place it on ST3.
ST1 498457000 ENGINE STAND ADAPTER RH
ST2 498457100 ENGINE STAND ADAPTER LH
ST3 499817000 ENGINE STAND
2) All parts should be thoroughly cleaned, paying special
attention to the engine oil passages, pistons and bearings.
3) Rotating parts and sliding parts such as piston, bearing
and gear should be coated with oil prior to assembly.
4) Be careful not to let oil, grease or coolant contact the
timing belt, clutch disc and flywheel.
5) All removed parts, if to be reused, should be reinstalled
in the original positions and directions.
6) Gaskets and lock washers must be replaced with new
ones. Liquid gasket should be used where specified to
prevent leakage.
7) Bolts, nuts and washers should be replaced with new
ones as required.
8) Even if necessary inspections have been made in
advance, proceed with assembly work while making
rechecks.
2. Hydraulic Lash Adjuster
A: INSPECTION
1) Disconnect blow-by hose from rocker cover.
2) Remove spark plug cap.
B2M0413A
3) Remove left and right rocker covers.
CAUTION:
Before removing left rocker cover, disconnect battery
cables and generator cable.
11
2-3SERVICE PROCEDURE
1. General Precautions - 2. Hydraulic Lash Adjuster

G2M0106
1. General Precautions
1) Before disassembling engine, place it on ST3.
ST1 498457000 ENGINE STAND ADAPTER RH
ST2 498457100 ENGINE STAND ADAPTER LH
ST3 499817000 ENGINE STAND
2) All parts should be thoroughly cleaned, paying special
attention to the engine oil passages, pistons and bearings.
3) Rotating parts and sliding parts such as piston, bearing
and gear should be coated with oil prior to assembly.
4) Be careful not to let oil, grease or coolant contact the
timing belt, clutch disc and flywheel.
5) All removed parts, if to be reused, should be reinstalled
in the original positions and directions.
6) Gaskets and lock washers must be replaced with new
ones. Liquid gasket should be used where specified to
prevent leakage.
7) Bolts, nuts and washers should be replaced with new
ones as required.
8) Even if necessary inspections have been made in
advance, proceed with assembly work while making
rechecks.
2. Hydraulic Lash Adjuster
A: INSPECTION
1) Disconnect blow-by hose from rocker cover.
2) Remove spark plug cap.
B2M0413A
3) Remove left and right rocker covers.
CAUTION:
Before removing left rocker cover, disconnect battery
cables and generator cable.
11
2-3SERVICE PROCEDURE
1. General Precautions - 2. Hydraulic Lash Adjuster

G2M0198
4) Manually push valve rocker (at lash adjuster location) to
check that there is no air in it.
NOTE:
When air is in lash adjuster, valve rocker moves when
pushed with fingers.
G2M0199
5) If air is in lash adjuster, remove valve rocker assembly
from engine and bleed air completely.
B2M0382A
B: AIR BLEEDING
1) Remove valve rocker assembly.
(1) Remove bolts

1through
4in numerical
sequence.
CAUTION:
Leave two or three threads of bolt

1engaged to retain
valve rocker assembly.
(2) Equally loosen bolts

5through
8all the way,
being careful that knock pin is not gouged.
2) Manually remove lash adjusters where air is trapped.
CAUTION:
If lash adjuster is difficult to remove manually, use pli-
ers. Be careful not to scratch lash adjuster.
12
2-3SERVICE PROCEDURE
2. Hydraulic Lash Adjuster

G2M0131
3) Bleed air from hydraulic lash adjuster as described
below:
(1) While dipping hydraulic lash adjuster in engine oil,
as shown in Figure, push check ball in usinga2mm
(0.08 in) diameter round bar.
(2) With check ball pushed in, manually move plunger
up and down at one second intervals until air bubbles
disappear.
(3) After air bubbles disappear, remove round bar and
quickly push plunger in to ensure it is locked. If plunger
does not lock properly, replace hydraulic lash adjuster.
CAUTION:
Leave hydraulic lash adjuster (after air is bled) in
engine oil until it is ready for installation.
G2M0200
4) Using ST;
(1) Insert lash adjuster into ST, and fill ST with engine
oil. Usinga2mm(0.08 in) diameter rod, push check
ball in.
ST 499597000 OIL SEAL GUIDE
(2) With check ball pushed in, push plunger at an inter-
val of one second.
(3) Move plunger up and down until air bubbles are no
longer emitted from lash adjuster.
NOTE:
Hold hydraulic lash adjusters vertically during air bleeding.
5) Remove the rod. Push plunger to ensure that air is
completely bled out.
CAUTION:
If plunger does not properly lock (when pushed),
replace lash adjuster with a new one.
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2-3SERVICE PROCEDURE
2. Hydraulic Lash Adjuster

G2M0131
C: INSPECTION
1. HYDRAULIC LASH ADJUSTER
1) Bleed air from hydraulic lash adjuster as described
below:
(1) While dipping hydraulic lash adjuster in engine oil,
as shown in Figure, push check ball in usinga2mm
(0.08 in) diameter round bar.
(2) With check ball pushed in, manually move plunger
up and down at one second intervals until air bubbles
disappear.
(3) After air bubbles disappear, remove round bar and
quickly push plunger in to ensure it is locked. If plunger
does not lock properly, replace hydraulic lash adjuster.
CAUTION:
Leave hydraulic lash adjuster (after air is bled) in
engine oil until it is ready for installation.
2) Replace hydraulic lash adjuster with a new one if valve
contact surface is scratched.
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2-3SERVICE PROCEDURE
4. Valve Rocker Assembly

B2M0077A
(6) Check the valve guide protrusion.
Valve guide protrusion: L
17.5—18.0 mm (0.689—0.709 in)
B2M0078
(7) Ream the inside of valve guide with ST. Gently
rotate the reamer clockwise while pressing it lightly into
valve guide, and return it also rotating clockwise. After
reaming, clean valve guide to remove chips.
ST 499767400 VALVE GUIDE REAMER
CAUTION:
Apply engine oil to the reamer when reaming.
If the inner surface of the valve guide is torn, the
edge of the reamer should be slightly ground with an
oil stone.
If the inner surface of the valve guide becomes lus-
trous and the reamer does not chips, use a new reamer
or remedy the reamer.
(8) Recheck the contact condition between valve and
valve seat after replacing valve guide.
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2-3SERVICE PROCEDURE
6. Cylinder Head

2. Engine Noise
Valve lash adjusters may make clicking noise once engine
starts. It is normal if clicking noise ceases after a few min-
utes.
If clicking noise continues after a few minutes, check
engine oil level and add oil if necessary.
Then, do as follows to cease clicking noise.
1) Warm-up engine for five minutes.
2) Turn ignition switch OFF.
3) Connect test mode connector.
4) Start the engine and run it at approximately 2,000 rpm
for twenty minutes.
5) Turn ignition switch OFF.
6) Disconnect test mode connector.
7) Start the engine and check that clicking noise is ceased.
If noise still exists, conduct troubleshooting procedures in
accordance with the following table.
CAUTION:
Do not disconnect spark plug cord while engine is run-
ning.
Type of sound Condition Possible cause
Regular clicking soundSound increases as engine
speed increases.Valve mechanism is defective.
Broken lash adjuster
Worn valve rocker
Worn camshaft
Broken valve spring
Worn valve lifter hole
Heavy and dull clankOil pressure is low.Worn crankshaft main bearing
Worn connecting rod bearing (big end)
Oil pressure is normal.Loose flywheel mounting bolts
Damaged engine mounting
High-pitched clank
(Spark knock)Sound is noticeable when
accelerating with an overload.Ignition timing advanced
Accumulation of carbon inside combustion chamber
Wrong spark plug
Improper gasoline
Clank when engine speed is
medium (1,000 to 2,000 rpm).Sound is reduced when fuel
injector connector of noisy
cylinder is disconnected.
(NOTE*)Worn crankshaft main bearing
Worn bearing at crankshaft end of connecting rod
Knocking sound when engine
is operating under idling speed
and engine is warm.Sound is reduced when fuel
injector connector of noisy
cylinder is disconnected.
(NOTE*)Worn cylinder liner and piston ring
Broken or stuck piston ring
Worn piston pin and hole at piston end of connecting rod
Sound is not reduced if each
fuel injector connector is
disconnected in turn. (NOTE*)Unusually worn valve lifter
Worn cam gear
Worn camshaft journal bore in crankcase
Squeaky sound—Insufficient generator lubrication
Rubbing sound—Defective generator brush and rotor contact
Gear scream when starting
engine—Defective ignition starter switch
Worn gear and starter pinion
Sound like polishing glass with
a dry cloth—Loose drive belt
Defective engine coolant pump shaft
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2-3DIAGNOSTICS
2. Engine Noise