check engine CHRYSLER VOYAGER 2001 Service Manual

(3) Using a suitable filter wrench, turn oil filter
(Fig. 89) counterclockwise to remove.
INSTALLATION
(1) Clean and check filter mounting surface. The
surface must be smooth, flat and free of debris or
pieces of gasket.
(2) Lubricate new oil filter gasket with clean
engine oil.
(3) Screw oil filter (Fig. 89) on until the gasket
contacts base. Tighten to 21 N´m (15 ft. lbs.).
OIL PAN
REMOVAL
(1) Raise vehicle on hoist and drain engine oil.
(2) Remove structural collar. (Refer to 9 -
ENGINE/ENGINE BLOCK/STRUCTURAL COVER -
REMOVAL)
(3) Remove air conditioning compressor bracket to
oil pan bolt.
(4) Remove bolts attaching oil pan.
(5) Remove oil pan.
(6) Clean oil pan and all gasket surfaces.
INSTALLATION
(1) Apply MopartEngine RTV GEN II at the oil
pump to engine block parting line (Fig. 90).
(2) Install the oil pan gasket to the block.
(3) Install pan and tighten the screws to 12 N´m
(105 in. lbs.).
(4) Install air conditioning compressor bracket to
oil pan bolt.
(5) Install structural collar. (Refer to 9 - ENGINE/
ENGINE BLOCK/STRUCTURAL COVER - INSTAL-
LATION)
(6) Lower vehicle and fill engine crankcase with
proper oil to correct level.
OIL PUMP
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(3) Remove timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL)
(4) Remove oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL)
(5) Remove crankshaft sprocket using Special
Tools 6793 and C-4685-C2 (Fig. 91).
(6) Remove crankshaft key (Fig. 92).
(7) Remove oil pick-up tube.
(8) Remove oil pump (Fig. 93) and front crankshaft
seal.
Fig. 89 Oil Filter
Fig. 90 Oil Pan Sealing - Typical
1 - SEALER LOCATIONS
9 - 52 ENGINE 2.4LRS
OIL FILTER (Continued)

can be inserted between cover and straight edge,
cover should be replaced.
(3) Measure thickness and diameter of outer rotor.
If outer rotor thickness measures 9.40 mm (0.370 in.)
or less (Fig. 98), or if the diameter is 79.95 mm
(3.148 in.) or less, replace outer rotor.
(4) If inner rotor measures 9.40 mm (0.370 in.) or
less replace inner rotor (Fig. 99).
Fig. 95 Oil Pump
1 - O-RING
2 - SEAL
3 - INNER ROTOR
4 - OIL PUMP COVER
5 - FASTENER
6 - OUTER ROTOR
7 - OIL PUMP BODY
Fig. 96 Oil Pump
1 - O-RING
2 - SEAL
3 - INNER ROTOR
4 - OIL PUMP COVER
5 - FASTENER
6 - OUTER ROTOR
7 - OIL PUMP BODY
Fig. 97 Checking Oil Pump Cover Flatness
1 - STRAIGHT EDGE
2 - FEELER GAUGE
3 - OIL PUMP COVER
Fig. 98 Measuring Outer Rotor Thickness
Fig. 99 Measuring Inner Rotor Thickness
9 - 54 ENGINE 2.4LRS
OIL PUMP (Continued)

(8) Remove vacuum lines for power brake booster,
LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at upper intake manifold fittings.
(9) Disconnect throttle, speed control (if equipped),
and transaxle control (31TH equipped only) cables
from throttle lever and bracket. (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/THROTTLE CONTROL
CABLE - REMOVAL)
(10) Remove the EGR tube. (Refer to 25 - EMIS-
SIONS CONTROL/EXHAUST GAS RECIRCULA-
TION/TUBE - REMOVAL)
(11) Remove the upper manifold support bracket
bolt to manifold (Fig. 107).
(12) Remove engine oil dipstick from tube.(13) Remove upper intake manifold bolts (Fig.
108). Remove upper intake manifold.
CAUTION: Cover intake manifold to prevent foreign
material from entering engine.
INSPECTION
(1) Check manifold surfaces for flatness with
straight edge. Surface must be flat within 0.15 mm
per 300 mm (0.006 in. per foot) of manifold length.
(2) Inspect manifold for cracks or distortion.
Replace manifold if necessary.
INSTALLATION
(1) Clean manifold sealing surfaces.
(2) Apply a 1.5 mm (0.060 in.) bead MopartGas-
ket Maker to the perimeter of the lower intake man-
ifold runner openings.
(3) Install upper intake manifold and tighten fas-
teners to 28 N´m (250 in. lbs.) in sequence shown in
(Fig. 108). Repeat this procedures until all fasteners
are at specified torque.
(4) Install engine oil dipstick.
(5) Install upper bolt in intake manifold to front
support bracket (Fig. 107). Torque to 28 N´m (250 in.
lbs.).
(6) Install EGR tube. (Refer to 25 - EMISSIONS
CONTROL/EXHAUST GAS RECIRCULATION/
TUBE - INSTALLATION)
(7) Install throttle cables in bracket.
(8) Connect throttle, speed control, (if equipped),
transaxle control (31TH equipped only) cables to
throttle lever.
Fig. 105 MAP SENSOR - 2.4L
1 - MAP SENSOR
Fig. 106 Throttle Body Electrical Connectors -
Typical
1 - IDLE AIR CONTROL MOTOR CONNECTOR
2 - TPS CONNECTOR
Fig. 107 Upper Intake Manifold Support Bracket
1 - NUT - BRACKET TO CYLINDER HEAD COVER
2 - BOLT - BRACKET TO UPPER INTAKE MANIFOLD
3 - UPPER INTAKE MANIFOLD SUPPORT BRACKET
RSENGINE 2.4L9-57
INTAKE MANIFOLD - UPPER (Continued)

(9) Connect vacuum lines for power brake booster,
LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at upper intake manifold fittings.
(10) Connect vacuum lines for purge solenoid and
PCV valve.
(11) Connect electrical connectors for MAP sensor,
throttle position sensor (TPS), and idle air control
(IAC) motor.
(12) Install air cleaner upper housing and air
intake tube to throttle body.
(13) Connect inlet air temperature sensor connec-
tor (Fig. 104).
(14) Connect negative cable to battery.
INTAKE MANIFOLD - LOWER
REMOVAL
(1) Perform fuel system pressure release proce-
durebefore attempting any repairs.(Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - STANDARD
PROCEDURE)
(2) Remove upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL)
CAUTION: Cover intake manifold openings to pre-
vent foreign material from entering engine.
(3) Disconnect fuel line. (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE)
(4) Drain the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
(5) Remove heater supply and radiator upper
hoses at intake manifold.
(6) Disconnect coolant temperature sensor/fuel
injector wire harness connector.
(7) Remove lower intake manifold support bracket
bolts (Fig. 109).(8) Loosen the lower intake manfold support
bracket lower bolt (Fig. 109).
(9) Disconnect fuel injector harness.
(10) Remove the bolts attaching the power steering
reservoir to manifold. Set reservoir aside. Do not dis-
connect line
(11) Remove lower intake manifold fasteners (Fig.
110). Remove the manifold from engine.
(12) Inspect the manifold. (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - INSPECTION)
INSPECTION
(1) Check manifold surfaces for flatness with
straight edge. Surface must be flat within 0.15 mm
per 300 mm (0.006 in. per foot) of manifold length.
(2) Inspect manifold for cracks or distortion.
Replace manifold if necessary.
INSTALLATION
If the following items were removed, install and
torque to specifications:
²Fuel rail bolts - 22 N´m (200 in. lbs.)
²Coolant outlet connector bolts - 28 N´m (250 in.
lbs.)
²Coolant temperature sensor - 7 N´m (60 in. lbs.)
(1) Position a new gasket on cylinder head and
install lower manifold.
(2) Install and tighten intake manifold fasteners to
28 N´m (250 in. lbs.) in the sequence shown in (Fig.
110). Repeat procedure until all bolts are at specified
torque.
(3) Install lower intake manifold support bracket
bolts (Fig. 109) and tighten to:
Fig. 108 Upper Intake Manifold Tightening Sequence
- 2.4L
Fig. 109 Lower Intake Manifold Support Bracket
1 - SUPPORT BRACKET
2 - BOLTS - UPPER TO MANIFOLD
3 - BOLT - LOWER TO ENGINE BLOCK
9 - 58 ENGINE 2.4LRS
INTAKE MANIFOLD - UPPER (Continued)

REMOVAL.............................114
INSTALLATION..........................115
CRANKSHAFT OIL SEAL - FRONT
REMOVAL.............................115
INSTALLATION..........................115
CRANKSHAFT OIL SEAL - REAR
REMOVAL.............................116
INSTALLATION..........................117
CRANKSHAFT REAR OIL SEAL RETAINER
REMOVAL.............................117
INSTALLATION..........................117
FLEX PLATE
REMOVAL.............................118
INSTALLATION..........................118
HYDRAULIC LIFTERS (CAM IN BLOCK)
DESCRIPTION..........................118
DIAGNOSIS AND TESTING................118
HYDRAULIC LIFTERS...................118
REMOVAL.............................119
INSTALLATION..........................119
PISTON & CONNECTING ROD
DESCRIPTION..........................119
OPERATION............................120
STANDARD PROCEDURE.................120
CONNECTING ROD AND BEARING -
FITTING.............................120
PISTON - FITTING.....................121
REMOVAL.............................121
INSTALLATION..........................122
PISTON RINGS
STANDARD PROCEDURE.................124
PISTON RING - FITTING................124
REMOVAL.............................124
INSTALLATION..........................125
VIBRATION DAMPER
REMOVAL.............................126
INSTALLATION..........................126
ENGINE MOUNTING
DESCRIPTION..........................127
FRONT MOUNT
REMOVAL.............................127
INSTALLATION..........................127
LEFT MOUNT
REMOVAL.............................128
INSTALLATION..........................128
REAR MOUNT
REMOVAL.............................129
INSTALLATION..........................130
RIGHT MOUNT
REMOVAL.............................130
INSTALLATION..........................131
LUBRICATION
DESCRIPTION..........................131
OPERATION............................131
DIAGNOSIS AND TESTING................131
ENGINE OIL PRESSURE................131OIL
STANDARD PROCEDURE.................132
ENGINE OIL CHANGE..................132
ENGINE OIL LEVEL CHECK..............133
OIL COOLER & LINES
DESCRIPTION..........................134
OPERATION............................134
REMOVAL.............................134
INSTALLATION..........................134
OIL FILTER
REMOVAL.............................135
INSTALLATION..........................135
OIL FILTER ADAPTER
REMOVAL.............................135
INSTALLATION..........................135
OIL PAN
REMOVAL.............................136
CLEANING.............................136
INSPECTION...........................136
INSTALLATION..........................136
OIL PRESSURE RELIEF VALVE
REMOVAL.............................137
INSTALLATION..........................137
OIL PRESSURE SENSOR/SWITCH
DESCRIPTION..........................137
OPERATION............................138
REMOVAL.............................138
INSTALLATION..........................138
OIL PUMP
DESCRIPTION..........................138
REMOVAL.............................138
DISASSEMBLY..........................138
CLEANING.............................138
INSPECTION...........................138
ASSEMBLY............................140
INSTALLATION..........................140
INTAKE MANIFOLD
DESCRIPTION..........................140
OPERATION............................141
DIAGNOSIS AND TESTING................141
INTAKE MANIFOLD LEAKS..............141
INTAKE MANIFOLD - UPPER 3.3L
STANDARD PROCEDURE.................141
MANIFOLD STRIPPED THREAD REPAIR....141
INTAKE MANIFOLD VACUUM PORT REPAIR . 142
REMOVAL.............................143
CLEANING.............................144
INSPECTION...........................144
INSTALLATION..........................144
INTAKE MANIFOLD - UPPER 3.8L
REMOVAL.............................145
CLEANING.............................146
INSPECTION...........................147
INSTALLATION..........................147
INTAKE MANIFOLD - LOWER
REMOVAL.............................148
CLEANING.............................148
9 - 72 ENGINE 3.3/3.8LRS

DIAGNOSIS AND TESTING - ENGINE
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 Engine Mechanical and the Engine
Performance diagnostic charts, for possible causes
and corrections of malfunctions (Refer to 9 - ENGINE
- DIAGNOSIS AND TESTING - MECHANICAL)
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING
- PERFORMANCE).
For fuel system diagnosis, (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DIAGNOSIS AND
TESTING).
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
²Lash Adjuster (Tappet) Noise Diagnosis
²Engine Oil Leak Inspection
DIAGNOSIS AND TESTING - ENGINE PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL
NOT START1. Weak battery. 1. Test battery. Charge or replace as
necessary. (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM - DIAGNOSIS AND
TESTING)
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 8 -
ELECTRICAL/STARTING - DIAGNOSIS
AND TESTING)
4. Faulty coil(s) or control unit. 4. Test and replace as needed. (Refer to
Appropriate Diagnostic Information)
5. Incorrect spark plug gap. 5. Set gap. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL - SPECIFICATIONS)
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 Appropriate Diagnostic Information)
8. Incorrect engine timing. 8. Check for a skipped timing belt/chain.
Fig. 2 Engine Identification
9 - 74 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)

DIAGNOSIS AND TESTING - ENGINE MECHANICAL
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. Thick oil 3. (a) Change engine oil and filter.
(b) Run engine to operating temperature.
(c) Change engine oil and filter again.
4. Low oil pressure. 4. Check and correct engine oil level.
5. Dirt in tappets/lash adjusters. 5. Replace rocker arm/hydraulic lash
adjuster assembly.
6. Worn rocker arms. 6. Inspect oil supply to rocker arms.
7. Worn tappets/lash adjusters. 7. Install new rocker arm/hydraulic lash
adjuster assembly.
8. Worn valve guides. 8. Replace cylinder head assembly.
9. Excessive runout of valve seats on valve
faces.9. Grind valve seats and valves.
10. Missing adjuster pivot. 10. Replace rocker arm/hydraulic lash
adjuster assembly.
CONNECTING
ROD NOISE1. 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. Thick oil 4. (a) Change engine oil and filter.
(b) Run engine to operating temperature.
(c) Change engine oil and filter again.
5. Excessive bearing clearance. 5. Measure bearings for correct clearance.
Repair as necessary.
6. Connecting rod journal out-of-round. 6. Replace crankshaft or grind surface.
7. Misaligned connecting rods. 7. Replace bent connecting rods.
MAIN BEARING
NOISE1. 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. Thick oil 4. (a) Change engine oil and filter.
(b) Run engine to operating temperature.
(c) Change engine oil and filter again.
5. Excessive bearing clearance. 5. Measure bearings for correct clearance.
Repair as necessary.
6. Excessive end play. 6. Check thrust bearing for wear on flanges.
7. Crankshaft journal out-of-round or worn. 7. Replace crankshaft or grind journals.
8. Loose flywheel or torque converter. 8. Tighten to correct torque.
9 - 76 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
OIL PRESSURE
DROP1. Low oil level. 1. Check engine oil level.
2. Faulty oil pressure sending unit. 2. Install new sending unit.
3. Low oil pressure. 3. Check sending unit and main bearing oil
clearance.
4. Clogged oil filter. 4. Install new oil filter.
5. Worn parts in oil pump. 5. Replace worn parts or pump.
6. Thin or diluted oil. 6. Change oil to correct viscosity.
7. Oil pump relief valve stuck. 7. Remove valve and inspect, clean, or
replace.
8. Oil pump suction tube loose. 8. Remove oil pan and install new tube or
clean, if necessary.
9. Oil pump cover warped or cracked. 9. Install new oil pump.
10. Excessive bearing clearance. 10. Measure bearings for correct clearance.
OIL LEAKS 1. Misaligned or deteriorated gaskets. 1. Replace gasket(s).
2. Loose fastener, broken or porous metal
part.2. Tighten, repair or replace the part.
3. Misaligned or deteriorated cup or
threaded plug.3. Replace as necessary.
OIL
CONSUMPTION
OR SPARK
PLUGS FOULED1. PCV system malfunction. 1. Check system and repair as necessary.
(Refer to 25 - EMISSIONS CONTROL/
EVAPORATIVE EMISSIONS/PCV VALVE -
DIAGNOSIS AND TESTING)
2. Worn, scuffed or broken rings. 2. Hone cylinder bores. Install new rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in grooves. 4. Remove rings and check grooves. If
groove is not proper width, replace piston.
5. Worn valve guide(s). 5. Replace cylinder head assembly.
6. Valve stem seal(s) worn or damaged. 6. Replace seal(s).
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
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
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair as necessary.(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5)If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
²Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
²Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
²Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
RSENGINE 3.3/3.8L9-77
ENGINE 3.3/3.8L (Continued)

²Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provides the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
²If the leakage occurs at the crankshaft rear oil
seal area, refer to the section, Inspection for Rear
Seal Area Leak.
(6) If no leaks are detected, turn off the air supply.
Remove the air hose, all plugs, and caps. Install the
PCV valve and fresh air hose (make-up air). Proceed
to next step.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
NOTE: If oil leakage is observed at the dipstick tube
to block location; remove the tube, clean and reseal
using MoparTStud & Bearing Mount (press fit tube
applications only), and for O-ring style tubes,
remove tube and replace the O-ring seal.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak. If a leak is
present in this area, remove transmission for further
inspection.
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, oil gallery cup
plug, bedplate to cylinder block mating surfaces
and seal bore. See proper repair procedures for
these items.
(4) If no leaks are detected, pressurize the crank-
case as previously described.
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible thecrankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
(7) After the oil leak root cause and appropriate
corrective action have been identified, replace compo-
nent(s) as necessary.
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE
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 the ignition coil electrical connector.
(5) Be sure throttle blade is fully open during the
compression check.
(6) Insert compression gage adaptor Special Tool
8116 or the equivalent, into the #1 spark plug hole in
cylinder head. Connect the 0±500 psi (Blue) pressure
transducer with cable adaptors to the DRBIIIt.
(7) Crank engine until maximum pressure is
reached on gage. Record this pressure as #1 cylinder
pressure.
(8) Repeat the previous step for all remaining cyl-
inders.
(9) Compression should not be less than 689 kPa
(100 psi) and not vary more than 25 percent from cyl-
inder to cylinder.
(10) If one or more cylinders have abnormally low
compression pressures, repeat the compression test.
(11) 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
9 - 78 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)

the cylinder in question.The recommended com-
pression pressures are to be used only as a
guide to diagnosing engine problems. An engine
should not be disassembled to determine the
cause of low compression unless some malfunc-
tion is present.
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
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, 1,379
kPa (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.
STANDARD PROCEDURE - MEASURING
BEARING CLEARANCE USING PLASTIGAGE
Engine crankshaft bearing clearances can be deter-
mined by use of Plastigage or equivalent. The follow-
ing is the recommended procedure for the use of
Plastigage:(1) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(2) Place a piece of Plastigage across the entire
width of the bearing shell in the cap approximately
6.35 mm (1/4 in.) off center and away from the oil
holes (Fig. 3). (In addition, suspected areas can be
checked by placing the Plastigage in the suspected
area). Torque the bearing cap bolts of the bearing
being checked to the proper specifications.
(3) Remove the bearing cap and compare the
width of the flattened Plastigage with the metric
scale provided on the package. Locate the band clos-
est to the same width. This band shows the amount
of clearance in thousandths of a millimeter. Differ-
ences in readings between the ends indicate the
amount of taper present. Record all readings taken.
Compare clearance measurements to specs found in
engine specifications (Refer to 9 - ENGINE - SPECI-
FICATIONS).Plastigage generally is accompa-
nied by two scales. One scale is in inches, the
other is a metric scale.
NOTE: Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
(4) Install the proper crankshaft bearings to
achieve the specified bearing clearances. (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT MAIN
BEARINGS - STANDARD PROCEDURE) (Refer to 9
- ENGINE/ENGINE BLOCK/CONNECTING ROD
BEARINGS - STANDARD PROCEDURE)
STANDARD PROCEDURE - FORM-IN-PLACE
GASKETS AND SEALERS
There are numerous places where form-in-place
gaskets are used on the engine. Care must be taken
Fig. 3 Plastigage Placed in Lower ShellÐTypical
1 - PLASTIC GAUGE
RSENGINE 3.3/3.8L9-79
ENGINE 3.3/3.8L (Continued)