CAUTION: Do not drive cup plug into the casting
as restricted cooling can result and cause serious
engine problems.
INSTALLATION
Thoroughly clean all debris/rust from inside of cup
plug hole in cylinder block or head. Be sure to
remove old sealer. Lightly coat inside of cup plug hole
with MopartStud and Bearing Mount Adhesive.
Make certain the new plug is cleaned of all oil or
grease. Using a proper driver, drive plug into hole so
that the sharp edge of the plug is at least 0.5 mm
(0.020 inch.) inside the lead in chamfer (Fig. 3).
It is not necessary to wait for curing of the sealant.
The cooling system can be refilled and the vehicle
placed in service immediately.
ENGINE PERFORMANCE
If a loss of performance is noticed, timing belt or
chain may have skipped one or two teeth. Camshaft
and crankshaft timing should be checked. Refer to
Group 9, Engine Timing belt or chain installation.
It is important that the vehicle is operating to it's
optimum performance level to maintain fuel economy
and lowest vehicle emissions. If vehicle is not operat-ing to these standards, refer to Engine Diagnosis in
this section. The following procedures can assist in
achieving the proper engine diagnosis.
(1) Test cranking amperage draw. Refer to Group
8B, Starting.
(2) Check intake manifold for vacuum leaks.
(3) Perform cylinder compression pressure test.
Refer to Engine Diagnosis in this section.
(4) Clean or replace spark plugs as necessary and
adjust gap as specified in Group 8D, Ignition System.
Tighten to specifications.
(5) Test resistance of spark plug cables. Refer to
Group 8D, Ignition System.
(6) Test ignition coils primary and secondary resis-
tance. Replace parts as necessary. Refer to Group 8D,
Ignition System.
(7) Check fuel pump pressure at idle and different
RPM ranges. Refer to Group 14, Fuel System for
specifications.
(8) The air filter elements should be replaced as
specified in Group 0, Lubrication and Maintenance.
(9) Inspect crankcase ventilation system. Refer to
Group 25, Emission Control Systems.
(10) Road test vehicle as a final test.HONING CYLINDER BORES
(1) Used carefully, the cylinder bore resizing hone,
recommended tool C-823 or equivalent, equipped
with 220 grit stones, is the best tool for this honing
procedure. In addition to deglazing, it will reduce
taper and out-of-round as well as removing light
scuffing, scoring or scratches. Usually a few strokes
Fig. 2 Access Plug
1 ± CRANKSHAFT BOLT ACCESS PLUG
2 ± RIGHT MOUNT BOLT ACCESS PLUG
3 ± FASCIA
4 ± SPLASH SHIELD
Fig. 3 Core Hole Plug Removal
1 ± CYLINDER BLOCK
2 ± REMOVE PLUG WITH PLIERS
3 ± STRIKE HERE WITH HAMMER
4 ± DRIFT PUNCH
5 ± CUP PLUG
PLENGINE 9 - 3
GENERAL INFORMATION (Continued)
ENGINE DIAGNOSIS
TABLE OF CONTENTS
page page
DIAGNOSIS AND TESTING
GENERAL INFORMATION...................8
INTAKE MANIFOLD LEAKAGE DIAGNOSIS......8
CYLINDER COMPRESSION PRESSURE TEST . . . 8
CYLINDER COMBUSTION PRESSURE
LEAKAGE TEST.........................9LASH ADJUSTER (TAPPET) NOISE
DIAGNOSIS............................9
ENGINE OIL LEAK INSPECTION..............9
ENGINE DIAGNOSISÐPERFORMANCE........11
ENGINE DIAGNOSISÐMECHANICAL.........12
DIAGNOSIS AND TESTING
GENERAL INFORMATION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either
mechanical (e.g., a strange noise), or performance
(e.g., engine idles rough and stalls).
Refer to the Service DiagnosisÐMechanical Chart
and the Service DiagnosisÐPerformance Chart, for
possible causes and corrections of malfunctions. Refer
to Group 14, Fuel System, for the fuel system diag-
nosis.
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can-
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following:
²Cylinder Compression Pressure Test
²Cylinder Combustion Pressure Leakage Test
²Engine Cylinder Head Gasket Failure Diagnosis
²Intake Manifold Leakage Diagnosis
INTAKE MANIFOLD LEAKAGE DIAGNOSIS
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water (Spray Bottle) at
the suspected leak area.
(3) If engine RPM'S change, the area of the sus-
pected leak has been found.
(4) Repair as required.
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Check engine oil level and add oil if necessary.
(2) Drive the vehicle until engine reaches normal
operating temperature. Select a route free from traf-
fic and other forms of congestion, observe all traffic
laws, and accelerate through the gears several times
briskly.
(3) Remove all spark plugs from engine. As spark
plugs are being removed, check electrodes for abnor-
mal firing indicators fouled, hot, oily, etc. Record cyl-
inder number of spark plug for future reference.
(4) Disconnect coil wire from distributor and
secure to good ground to prevent a spark from start-
ing a fire (Conventional Ignition System). For Direct
Ignition System DIS disconnect the coil connector.
(5) Be sure throttle blade is fully open during the
compression check.
(6) Insert compression gage adaptor into the #1
spark plug hole in cylinder head. Crank engine until
maximum pressure is reached on gage. Record this
pressure as #1 cylinder pressure.
(7) Repeat the previous step for all remaining cyl-
inders.
(8) Compression should not be less than (689 kPa)
100 psi and not vary more than 25 percent from cyl-
inder to cylinder.
(9) If one or more cylinders have abnormally low
compression pressures, repeat the compression test.
(10) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
the cylinder in question.The recommended com-
pression pressures are to be used only as a
guide to diagnosing engine problems. An engine
9 - 8 ENGINEPL
should not be disassembled to determine the
cause of low compression unless some malfunc-
tion is present.
(11) Clean or replace spark plugs as necessary and
adjust gap as specified in Group 8, Electrical.
Tighten to specifications.
(12) Test resistance of spark plug cables. Refer to
Group 8, Electrical Ignition System Secondary Cir-
cuit Inspection.
(13) Test coil output voltage, primary and second-
ary resistance. Replace parts as necessary. Refer to
Group 8, Electrical Ignition System.
(14) Check fuel pump pressure at idle and differ-
ent RPM ranges. Refer to Group 14, Fuel System for
Specifications.
(15) The air filter elements should be replaced as
specified in Group 0, Lubrication and Maintenance.
(16) Inspect crankcase ventilation system as out
lined in Group 0, Lubrication and Maintenance. For
emission controls see Group 25, Emission Controls
for service procedures.
(17) Inspect and adjust accessory belt drives refer-
ring to Group 7, Cooling System, Accessory Drive
Belts for proper adjustments.
(18) Road test vehicle as a final test.
CYLINDER COMBUSTION PRESSURE LEAKAGE
TEST
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
WARNING: DO NOT REMOVE THE RADIATOR CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the radiator cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn the engine
OFF.
Clean spark plug recesses with compressed air.
Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner.
Calibrate the tester according to the manufactur-
er's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379kPa (200 psi) maximum, with 552 kPa (80 psi) rec-
ommended.
Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage per cylinder.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
LASH ADJUSTER (TAPPET) NOISE DIAGNOSIS
A tappet-like noise may be produced from several
items. Check the following items.
(1) Engine oil level too high or too low. This may
cause aerated oil to enter the adjusters and cause
them to be spongy.
(2) Insufficient running time after rebuilding cylin-
der head. Low speed running up to 1 hour may be
required.
(3) During this time, turn engine off and let set for
a few minutes before restarting. Repeat this several
times after engine has reached normal operating
temperature.
(4) Low oil pressure.
(5) The oil restrictor pressed into the vertical oil
passage to the cylinder head is plugged with debris.
(6) Air ingested into oil due to broken or cracked
oil pump pick up.
(7) Worn valve guides.
(8) Rocker arm ears contacting valve spring
retainer.
(9) Rocker arm loose, adjuster stuck or at maxi-
mum extension and still leaves lash in the system.
(10) Faulty lash adjuster.
a. Check lash adjusters for sponginess while
installed in cylinder head. Depress part of rocker
arm over adjuster. Normal adjusters should feel very
firm. Spongy adjusters can be bottomed out easily.
b. Remove suspected rocker arms (sohc) or lash
adjuster (dohc) and replace.
ENGINE OIL LEAK INSPECTION
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
PLENGINE 9 - 9
DIAGNOSIS AND TESTING (Continued)
ENGINE DIAGNOSISÐPERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery. 1. Test battery. Charge or replace
as necessary. Refer to Group 8A,
Battery.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to terminals.
3. Faulty starter. 3. Test starting system. Refer to
Group 8B, Starting.
4. Faulty coil(s) or control unit. 4. Test and replace as needed.
Refer to Group 8D, Ignition System.
5. Incorrect spark plug gap. 5. Set gap. Refer to Group 8D,
Ignition System.
6. Contamination in fuel system. 6. Clean system and replace fuel
filter.
7. Faulty fuel pump. 7. Test fuel pump and replace as
needed. Refer to Group 14, Fuel
System.
8. Incorrect engine timing. 8. Check for a skipped timing
belt/chain.
ENGINE STALLS OR IDLES
ROUGH1. Idle speed too low. 1. Test minimum air flow. Refer to
Group 14, Fuel System.
2. Incorrect fuel mixture. 2. Refer to Group 14, Fuel System.
3. Intake manifold leakage. 3. Inspect intake manifold, manifold
gasket, and vacuum hoses.
4. Faulty coil(s). 4. Test and replace as necessary.
Refer to Group 8D, Ignition System.
ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped plugs. 1. Clean plugs and set gap. Refer to
Group 8D, Ignition System.
2. Contamination in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. Test and replace as necessary.
Refer to Group 14, Fuel System.
4. Incorrect valve timing. 4. Correct valve timing.
5. Leaking cylinder head gasket. 5. Replace cylinder head gasket.
6. Low compression. 6. Test compression of each
cylinder.
7. Burned, warped, or pitted valves. 7. Replace valves.
8. Plugged or restricted exhaust
system.8. Install new parts, as necessary.
9. Faulty coil(s). 9. Test and replace as necessary.
Refer to Group 8D, Ignition System.
PLENGINE 9 - 11
DIAGNOSIS AND TESTING (Continued)
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE MISSES ON
ACCELERATION1. Dirty or incorrectly gapped spark
plugs.1. Clean spark plugs and set gap.
Refer to Group 8D, Ignition System.
2. Contamination in Fuel System. 2. Clean fuel system and replace
fuel filter.
3. Burned, warped, or pitted valves. 3. Replace valves.
4. Faulty coil(s). 4. Test and replace as necessary.
Refer to Group 8D, Ignition System.
ENGINE MISSES AT HIGH SPEED 1. Dirty or incorrect spark plug gap. 1. Clean spark plugs and set gap.
Refer to Group 8D, Ignition System.
2. Faulty coil(s). 2. Test and replace as necessary.
Refer to Group 8D, Ignition System.
3. Dirty fuel injector(s). Test and replace as necessary.
Refer to Group 14, Fuel System.
4. Contamination in fuel system. 4. Clean system and replace fuel
filter.
ENGINE DIAGNOSISÐMECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES 1. High or low oil level in
crankcase.1. Check and correct engine oil
level.
2. Thin or diluted oil. 2. Change oil to correct viscosity.
3. Low oil pressure. 3. Check and correct engine oil
level.
4. Dirt in tappets/lash adjusters. 4. Replace rocker arm/hydraulic
lash adjuster assembly.
5. Worn rocker arms. 5. Inspect oil supply to rocker arms.
6. Worn tappets/lash adjusters. 6. Install new rocker arm/hydraulic
lash adjuster assembly.
7. Worn valve guides. 7. Ream guides and install new
valves with oversize stems.
8. Excessive runout of valve seats
on valve faces.8. Grind valve seats and valves.
9. Missing adjuster pivot. 9. Replace rocker arm/hydraulic
lash adjuster assembly.
CONNECTING ROD NOISE 1. Insufficient oil supply. 1. Check engine oil level.
2. Low oil pressure. 2. Check engine oil level. Inspect oil
pump relief valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Excessive bearing clearance. 4. Measure bearings for correct
clearance. Repair as necessary.
5. Connecting rod journal
out-of-round.5. Replace crankshaft or grind
surface.
6. Misaligned connecting rods. 6. Replace bent connecting rods.
9 - 12 ENGINEPL
DIAGNOSIS AND TESTING (Continued)
(8) Install lower engine torque strut. Refer to pro-
cedure in this section.
(9) Connect exhaust system to manifold. Refer to
Group 11, Exhaust System for procedure and torque
specifications.
(10) Connect the downstream oxygen sensor.
(11) Install A/C compressor and hoses. Refer to
Group 24, Heater and Air Conditioning for procedure.
(12) Install accessory drive belts. Refer to Group 7,
Cooling System Accessory Drive Section for belt ten-
sion adjustment.
(13) Install inner splash shield.
(14) Install wheels and lower vehicle.
(15) Install power steering pump and reservoir.
Refer to Group 7, Cooling System Accessory Drive
Section for belt tension adjustment.
(16)Manual Transmission:Connect clutch cable,
reverse light electrical connector and shift linkages.
Refer to Group 6, Clutch.
(17)Automatic Transmission:Connect shifter,
kickdown linkage and cooler lines. Refer to Group 21,
Transaxle for procedures.
(18) Connect fuel line and heater hoses.
(19)
Install all ground straps. Connect engine wiring
harness. Refer to Group 8, Electrical for procedure.
(20) Install lower radiator hose, fan module, and
upper radiator hose. Refer to Group 7, Cooling Sys-
tem for procedures
(21) Fill cooling system. Refer to Group 7, Cooling
System for filling procedure.
(22) Install battery tray and battery.
(23) Install air cleaner housing assembly and con-
nect intake duct to intake manifold.(24) Connect all throttle body electrical connectors
and linkage.
(25) Install oil filter. Fill engine crankcase with
proper oil to correct level.
(26) Perform camshaft and crankshaft timing
relearn procedure as follows:
²Connect the DRB scan tool to the data link
(diagnostic) connector. This connector is located in
the passenger compartment; at the lower edge of
instrument panel; near the steering column.
²Turn the ignition switch on and access the ªmis-
cellaneousº screen.
²Select ªre-learn cam/crankº option and follow
directions on DRB screen.
Fig. 25 Left Mount Through Bolt
1 ± MOUNT BRACKET
2 ± BOLT
3 ± MOUNT
Fig. 26 Positioning Engine Cradle Support Post
1 ± SAFETY STRAPS
2 ± PLACE REAR POSTS INTO LOCATING HOLES
3 ± SPECIAL TOOL 6848
4 ± SPECIAL TOOL 6710
5 ± SPECIAL TOOL 6135
6 ± SAFETY STRAPS
7 ± PLACE FRONT POST UNDER BLOCK FLANGE
PL2.0L SOHC ENGINE 9 - 27
REMOVAL AND INSTALLATION (Continued)
(27) Start engine and run until operating temper-
ature is reached.
(28) Ensure engine is properly positioned. Refer to
Torque Struts in this section for adjustment proce-
dure.
(29) Adjust transmission linkage, if necessary.
INTAKE MANIFOLD
REMOVAL
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
SERVICE VEHICLES IN WELL VENTILATED AREAS
AND AVOID IGNITION SOURCES. NEVER SMOKE
WHILE SERVICING THE VEHICLE.
(1) Disconnect negative cable from battery.
(2) Remove the inlet air duct from intake manifold
to throttle body.
(3) Perform fuel system pressure release procedure
before attempting any repairs.Refer to Group 14,
Fuel System for procedures.
WARNING: WRAP SHOP TOWELS AROUND FUEL
HOSE TO CATCH ANY GASOLINE SPILLAGE
(4) Disconnect fuel supply line quick connect at the
fuel tube assembly. Refer to Group 14, Fuel System
for procedures.
(5) Remove fuel rail assembly attaching screws
and remove fuel rail assembly from engine. Cover
injector holes with suitable covering.
CAUTION: Do not set fuel injectors on their tips,
damage may occur to the injectors
(6) Disconnect brake booster hose (Fig. 27) and
PCV hose (Fig. 28) from intake manifold.
(7) Disconnect Manifold Absolute Pressure (MAP)
sensor electrical connector (Fig. 29).
(8) Disconnect knock sensor electrical connector
(Fig. 30).
(9) Disconnect wiring at starter.
(10) Remove the intake manifold to lower support
bracket bolts (Fig. 31).
(11) Remove intake manifold screws and washers.
Discard the fasteners. Remove intake manifold.
INSTALLATION
Before installing manifold. Clean all mating sur-
faces. Replace all O-ring gaskets with new gaskets
(Fig. 33). All intake manifold fasteners and washers
are to be discarded andNEWfasteners and washers
are to be used.(1) Install intake manifold onto cylinder head and
tighten fasteners to 12 N´m (105 in. lbs.) in sequence
shown in (Fig. 32).
Fig. 27 Brake Booster Hose
Fig. 28 PCV Hose
9 - 28 2.0L SOHC ENGINEPL
REMOVAL AND INSTALLATION (Continued)
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) relay will remain ener-
gized for 7 minutes or until the ignition switch is
turned to the OFF position, or Stop All Test is
selected.
EXHAUST MANIFOLD
REMOVAL
(1) Disconnect negative cable from battery.
(2) Raise vehicle on hoist.
(3) Remove bolt attaching the wire harness heat
shield to the exhaust manifold support bracket (Fed-
eral and LEV) (Fig. 34), or to the exhaust manifold
(ULEV).
(4) Remove exhaust manifold support bracket
(Federal and LEV) (Fig. 35).
(5) Remove fasteners attaching exhaust system
flex joint to exhaust manifold flange. Move exhaust
system rearward to clear flange studs.
(6) ULEV equippedÐremove the support bracket
from cylinder block to exhaust manifold (Fig. 36).
(7) Lower vehicle.
(8) Disconnect CCV hose from rear of cylinder
head cover.
(9) Disconnect oxygen sensor connector and har-
ness clip.
(10) Remove heat shield attaching bolts (Fig. 37).
(11) Remove upper heat shield for access to mani-
fold bolts.
(12) Remove exhaust manifold bolts.
(13) ULEV equippedÐremove cylinder head cover.
Refer to procedure in this section. Cover cylinder
head opening with a suitable covering.
(14) Remove exhaust manifold from top of vehicle,
between cylinder head and cowl.
INSTALLATION
(1) Position exhaust manifold and gasket in place.
(2) Install exhaust manifold bolts and tighten in
sequence shown in (Fig. 38) to 23 N´m (200 in. lbs.).
(3) ULEV equippedÐposition upper heat shield on
exhaust manifold. Install bolts and tighten to 23 N´m
(200 in. lbs.).
(4) Position lower and upper heat shield on
exhaust manifold. Install heat shield bolts and
tighten to 11 N´m (95 in. lbs.) (Fig. 37).
(5) Connect oxygen sensor electrical connector and
harness clip.
(6) ULEV equippedÐinstall cylinder head cover.
Refer to procedures in this section.
Fig. 33 Intake Manifold Gaskets
1 ± INTAKE MANIFOLD O-RING GASKETS
Fig. 34 Wire Harness Heat Shield BoltÐFederal &
LEV Shown, ULEV Similar
1 ± BOLT
2 ± BRACKET
3 ± HEAT SHIELD
Fig. 35 Exhaust Manifold Support BracketÐFederal
& LEV
1 ± BRACKET
2 ± BOLT (M10)
3 ± BOLT (M12)
4 ± NUT
9 - 30 2.0L SOHC ENGINEPL
REMOVAL AND INSTALLATION (Continued)