service CHRYSLER VOYAGER 1996 Service Manual

CAUTION: Be sure that the tapped holes maintain
the original centerline.
Heli-Coil tools and inserts are readily available
from automotive parts jobbers.
HYDROSTATIC LOCKED ENGINE
When an engine is suspected to be hydrostatically
locked, regardless of what caused the problem, these
steps should be used.
CAUTION: Do Not Use Starter Motor To Rotate
Engine, severe damage may occur.
(1) Inspect air cleaner, induction system and
intake manifold to insure system is dry and clear of
foreign material.
(2) Remove negative battery cable.
(3) Place a shop towel around the spark plugs
when removing them from the engine. This will catch
any fluid that may possibly be in the cylinder under
pressure.
(4) With all spark plugs removed, rotate engine
crankshaft using a breaker bar and socket.
(5) Identify the fluid in the cylinder(s) (i.e., cool-
ant, fuel, oil or other).
(6) Make sure all fluid has been removed from the
cylinders. Inspect engine for damage (i.e., Connecting
Rods, Pistons, Valves etc.)
(7) Repair engine or components as necessary to
prevent this problem from occurring again.
CAUTION: Squirt approximately 1 teaspoon of oil
into cylinders, rotate engine to lubricate the cylin-
der walls to prevent damage on restart.
(8) Install new spark plugs.
(9) Drain engine oil and remove oil filter.
(10) Fill engine with specified amount of approved
oil and install new oil filter.
(11) Connect negative battery cable.
(12) Start engine and check for any leaks.
ENGINE OIL
Checking Oil Level
To assure proper engine lubrication, the engine oil
must be maintained at the correct level. Check the
oil level at regular intervals, such as every fuel stop.
The best time to check the oil level is about 5 min-
utes after a fully warmed-up engine is shut off, or
before starting the vehicle after it has sat overnight.
Checking the oil while the vehicle is on level
ground, will improve the accuracy of the oil level
readings. For 2.4L, 3.3L and 3.8L engines, maintain
the oil level between the MIN and MAX markings on
the dipstick. Adding one quart of oil when the read-ing is at the MIN mark will result in a MAX reading
on these engines. For the 3.0L engine, add one full
quart when the level on the dipstick is at or below
the ADD mark.
ENGINE OIL SERVICE
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY. CONTACT YOUR DEALER OR GOVERN-
MENT AGENCY FOR LOCATION OF COLLECTION
CENTER IN YOUR AREA.
ENGINE OIL SPECIFICATION
CAUTION: Do not use non-detergent or straight
mineral oil when adding or changing crankcase
lubricant. Engine failure can result.
NSENGINE 9 - 5
GENERAL INFORMATION (Continued)

API SERVICE GRADE CERTIFIED
Use an engine oil that is API Service Grade Certi-
fied. MOPARtprovides engine oils that conforms to
this service grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. Use only, engine oils with multi-
ple viscosities such as 5W-30 or 10W-30. These are
specified with a dual SAE viscosity grade which indi-
cates the cold-to-hot temperature viscosity range.
Select an engine oil that is best suited to your par-
ticular temperature range and variation (Fig. 5).
ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for
gasoline engines. They are designated as either
ENERGY CONSERVING or ENERGY CONSERV-
ING II.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans (Fig. 6).
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals
described in the Maintenance Schedule.
TO CHANGE ENGINE OIL
Run engine until achieving normal operating tem-
perature.
(1) Position the vehicle on a level surface and turn
engine off.
(2) Hoist and support vehicle on safety stands.
Refer to Hoisting and Jacking Recommendations.
(3) Remove oil fill cap.
(4) Place a suitable drain pan under crankcase
drain.
(5) Remove drain plug from crankcase and allow
oil to drain into pan. Inspect drain plug threads for
stretching or other damage. Replace drain plug and
gasket if damaged.
(6) Install drain plug in crankcase.
(7) Lower vehicle and fill crankcase with specified
type and amount of engine oil described in this sec-
tion.
(8) Install oil fill cap.
(9) Start engine and inspect for leaks.
(10) Stop engine and inspect oil level.
Fig. 5 Temperature/Engine Oil Viscosity
Fig. 6 Engine Oil Container Standard Notations
9 - 6 ENGINENS
GENERAL INFORMATION (Continued)

ENGINE DIAGNOSIS
INDEX
page page
DIAGNOSIS AND TESTING
CYLINDER COMBUSTION
PRESSURE LEAKAGE TEST.............. 8
CYLINDER COMPRESSION PRESSURE TEST . . 7
ENGINE DIAGNOSISÐMECHANICAL......... 12
ENGINE DIAGNOSISÐPERFORMANCE...... 10GENERAL INFORMATION.................. 7
INSPECTION
(ENGINE OIL LEAKS IN GENERAL)......... 8
INTAKE MANIFOLD LEAKAGE DIAGNOSIS..... 7
LASH ADJUSTER (TAPPET)
NOISE DIAGNOSIS...................... 8
DIAGNOSIS AND TESTING
GENERAL INFORMATION
Engine diagnosis is helpful in determining the
causes of malfunctions.
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 a change in RPM'S, the area of the suspected
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 (689kPa)
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
should not be disassembled to determine the
NSENGINE 9 - 7

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, 1 379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.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.
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 lash adjusters, and disassem-
bleDo not reuse retainer caps. Do not inter-
change parts and make sure that care and
cleanliness is exercised in the handling of parts.
c. Clean out dirt and varnish with solvent.
d. Reassemble with engine oil.
e. Check for sponginess.
f. If still spongy, replace with new adjuster.
INSPECTION (ENGINE OIL LEAKS IN GENERAL)
Begin with a through 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.
9 - 8 ENGINENS
DIAGNOSIS AND TESTING (Continued)

(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 per service manual instructions.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24km (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:
(6) Disconnect the fresh air hose (makeup air) at
the cylinder head cover and plug or cap the nipple on
the cover.
(7) Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
(8) Attach an air hose with pressure gauge and
regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
(9) Gradually 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 provide the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
(10) If the leakage occurs at the rear oil seal area,
refer to the section, Inspection for Rear Seal Area
Leak.
(11) If no leaks are detected, turn off the air sup-
ply and remove the air hose and all plugs and caps.
Install the PCV valve and breather cap hose. Proceed
to next step.
(12) 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.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 galley cup
plug, bedplate to cylinder block mating surfaces
and seal bore. See proper repair procedures for
these items.
(4) If no leaks are detected, pressurized the crank-
case as outlined in the, Inspection (Engine oil Leaks
in general)
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 the
crankshaft 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. Refer to Rear
Crankshaft Seals, for proper replacement procedures.
NSENGINE 9 - 9
DIAGNOSIS AND TESTING (Continued)

2.4L ENGINE
INDEX
page page
DESCRIPTION AND OPERATION
ENGINE COMPONENTS.................. 15
ENGINE IDENTIFICATION................. 14
ENGINE LUBRICATION SYSTEM............ 14
DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE......... 16
SERVICE PROCEDURES
CRANKSHAFT END PLAY................. 20
FITTING CONNECTING ROD BEARINGS..... 18
FITTING MAIN BEARINGS................. 19
FITTING PISTON RINGS.................. 16
FITTING PISTONS....................... 16
VALVE SERVICE RECONDITION............ 21
REMOVAL AND INSTALLATION
BALANCE SHAFTS CARRIER ASSEMBLY..... 30
CAMSHAFT FOLLOWER.................. 30
CAMSHAFT OIL SEALÐFRONT............. 41
CAMSHAFT............................ 28
CRANKSHAFT OIL SEALÐFRONT........... 42
CRANKSHAFT OIL SEALÐREAR............ 43
CRANKSHAFT.......................... 46
CYLINDER HEAD COVER................. 28
CYLINDER HEAD........................ 34
ENGINE ASSEMBLY...................... 26
ENGINE MOUNTÐFRONT................. 23
ENGINE MOUNTÐLEFT.................. 24
ENGINE MOUNTÐREAR.................. 25
ENGINE MOUNTÐRIGHT................. 24HYDRAULIC LASH ADJUSTER.............. 33
OILFILTER ............................ 47
OILPAN ............................... 45
OIL PUMP............................. 47
PISTON AND CONNECTING ROD........... 49
STRUCTURAL COLLAR................... 25
TIMING BELT COVER.................... 37
TIMING BELT TENSIONER ASSEMBLY....... 40
TIMING BELT........................... 37
VALVE SPRINGS AND
VALVE SEALS IN VEHICLE............... 33
VALVES AND VALVE SPRINGS............. 35
VIBRATION DAMPER.................... 36
DISASSEMBLY AND ASSEMBLY
OIL PUMP............................. 50
CLEANING AND INSPECTION
OIL PUMP............................. 52
CRANKSHAFT.......................... 52
CYLINDER BLOCK....................... 54
CYLINDER HEAD........................ 51
VALVE AND VALVE SPRING................ 51
ADJUSTMENTS
ENGINE MOUNTS....................... 54
SPECIFICATIONS
2.4L ENGINE........................... 55
TORQUE CHART 2.4L.................... 57
SPECIAL TOOLS
2.4L ENGINE........................... 58
DESCRIPTION AND OPERATION
ENGINE IDENTIFICATION
The engine identification number is located on the
rear of the cylinder block (Fig. 1).
ENGINE LUBRICATION SYSTEM
OIL PAN
A structural die cast aluminum oil pan provides
lower engine protection as well as serving as the
engine oil reservoir. Oil pan is attached to block and
sealed with a gasket. The oil pickup tube has a
strainer and cover.
PRESSURE LUBRICATION
Oil drawn up through the pickup tube is pressur-
ized by the pump and routed through the full flow fil-
ter to the main oil gallery running the length of thecylinder block. Oil pickup, pump and check valve pro-
vide oil flow to the main oil gallery.
MAIN/ROD BEARINGS
A diagonal hole in each bulkhead feeds oil to each
main bearing. Drilled passages within the crankshaft
route oil from main bearing journals to connecting
rod journals.
CAMSHAFT/HYDRAULIC LASH ADJUSTERS
A vertical hole at the number five bulkhead routes
pressurized oil through a restrictor up past a cylin-
der head bolt to an oil gallery running the length of
the cylinder head. The camshaft journals are par-
tially slotted to allow a predetermined amount of
pressurized oil to pass into the bearing cap cavities
with small holes directed to spray lubricate the cam-
shaft lobes.
9 - 14 2.4L ENGINENS

BALANCE SHAFTS
Balance shaft lubrication is provided through an
oil passage from the number 1 main bearing cap
through the balance shaft carrier support leg. This
passage directly supplies oil to the front bearings and
internal machined passages in the shafts that routes
oil from front to rear shaft bearing journals
SPLASH LUBRICATION
Oil returning to the pan from pressurized compo-
nents supplies lubrication to the valve stems. Cylin-
der bores and wrist pins are splash lubricated from
directed slots on the connecting rod thrust collars.
ENGINE COMPONENTS
BALANCE SHAFTS:2.4L engines are equipped
with two balance shafts installed in a carrier
attached to the lower crankcase. The shafts intercon-
nect through gears to rotate in opposite directions.These gears are driven by a short chain from the
crankshaft, to rotate at two times crankshaft speed.
This counterbalances certain engine reciprocating
masses.
CYLINDER BLOCK AND BEDPLATE ASSEM-
B LY:A closed deck design is used for cooling and
weight reduction with water pump molded into the
block. Nominal wall thickness is 4.5 mm. The bed-
plate incorporates main bearing caps. Rear seal
retainer is integral with the block.
CRANKSHAFT:A nodular cast iron crankshaft is
used. The engine has 5 main bearings, with number
3 flanged to control thrust. The 60 mm diameter
main and 50 mm diameter crank pin journals (all)
have undercut fillets that are deep rolled for added
strength. To evenly distribute bearing loads and min-
imize internal stress, 8 counterweights are used.
Hydrodynamic seals provide end sealing, where the
crankshaft exits the block. Anaerobic gasket material
is used for parting line sealing in the block. A sin-
tered powder metal timing belt sprocket is mounted
on the crankshaft nose. This sprocket provides
motive power; via timing belt to the camshaft sprock-
ets (providing timed valve actuation) and to the
water pump.
PISTONS:There is provisions for free wheeling
valve train. Piston has a unique height. All engines
use pressed in piston pins to attach forged powder
metal connecting rods. Incorporate hex head cap
screw threaded into the connecting rod. Piston and
Rods are serviced as a assembly.
PISTONS RINGS:The piston rings include a
molybdenum faced top ring for reliable compression
EngineÐ2.4L
Fig. 1 Engine Identification
NS2.4L ENGINE 9 - 15
DESCRIPTION AND OPERATION (Continued)

sealing and a chrome plated taper faced intermediate
ring for additional cylinder pressure control. There
are also standard oil control rings.
CYLINDER HEAD:Features a Dual Over Head
Camshaft (DOHC) 4 valves per cylinder cross flow
design. The valves are arranged in two inline banks,
with the ports of the bank of two intake valves per
cylinder facing toward the radiator side of engine
and ports of the bank of two exhaust valves per cyl-
inder facing toward the dash panel. Incorporates
powder metal valve guides and seats. Integral oil gal-
leys within the cylinder head supplies oil to the
hydraulic lash adjusters, camshaft and valve mecha-
nisms.
CAMSHAFTS:The nodular iron camshafts have
six bearing journals and 2 cam lobes per cylinder.
Flanges at the rear journals control camshaft end
play. Provision for cam position sensor is located on
the intake camshaft at the rear of cylinder head. A
hydrodynamic oil seal is used for oil control at the
front of the camshaft.
VALVES:4 valves per cylinder are actuated by
roller cam followers which pivot on stationary
hydraulic lash adjusters. All valves have 6 mm diam-
eter chrome plated valve stems. The valve sizes are
34.8 mm (1.370 inch.) diameter intake valves and
30.5 mm (1.20 inch.) diameter exhaust valves. Viton
rubber valve stem seals are integral with the spring
seats. Valve springs, spring retainers, and locks are
conventional.
INTAKE MANIFOLD:The intake manifold is a
two piece aluminum casting, attached to the cylinder
head with ten screws. This long branch fan design
enhances low and midspeed torque, while minimizing
undesirable inlet noise.
EXHAUST MANIFOLD:The exhaust manifold is
made of cast iron for strength and high tempera-
tures.
ENGINE LUBRICATION:Refer to Group 0
Lubrication and Maintenance for recommended oil to
be used in various engine application. System is full
flow filtration, pressure feed type. The oil pump is
mounted in the front engine cover and driven by the
crankshaft. Pressurized oil is then routed through
the main oil gallery, running the length of the cylin-
der block, supplying main and rod bearings with fur-
ther routing. Pistons are lubricated from rod bearing
throw off and lubricating slots on the connecting rod
assemblies. Camshaft and valve mechanisms are
lubricated from a full length cylinder head oil gallery
supplied from the crankcase main oil gallery.DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE
(1) Remove oil pressure sending unit and install
gauge assembly C-3292.
(2) Run engine until thermostat opens.
CAUTION: If oil pressure is 0 at idle, Do Not Run
engine at 3000 RPM
(3) Oil Pressure:Curb Idle25 kPa (4 psi) mini-
mum3000 RPM170/550 kPa (25/80 psi).
(4) If oil pressure is 0 at idle. Shut off engine,
check for pressure relief valve stuck open or a
clogged oil pickup screen.
SERVICE PROCEDURES
FITTING PISTONS
Piston and cylinder wall must be clean and dry.
Piston diameter should be measured 90 degrees to
piston pin about 14 mm (9/16 inch.) from the bottom
of the skirt as shown in (Fig. 3). Cylinder bores
should be measured halfway down the cylinder bore
and transverse to the engine crankshaft center line
shown in (Fig. 2). Refer to Cylinder Bore and Piston
Specification Chart.
Correct piston to bore clearance must be estab-
lished in order to assure quiet and economical oper-
ation.
Chrysler engines use pistons designed specifically
for each engine model. Clearance and sizing locations
vary with respect to engine model.
NOTE: Pistons and cylinder bores should be mea-
sured at normal room temperature, 70ÉF (21ÉC).
FITTING PISTON RINGS
(1) Wipe cylinder bore clean. Insert ring and push
down with piston to ensure it is square in bore. The
ring gap measurement must be made with the ring
positioning at least 12 mm (0.50 inch) from bottom of
cylinder bore. Check gap with feeler gauge (Fig. 4).
Refer to specification in Piston Ring Specification
Chart.
(2) Check piston ring to groove side clearance (Fig.
5). Refer to specification in Piston Ring Specification
Chart.
9 - 16 2.4L ENGINENS
DESCRIPTION AND OPERATION (Continued)

PISTON RINGSÐINSTALLATION
(1) Install rings with manufacturers I.D. mark fac-
ing up, to the top of the piston (Fig. 6).
CAUTION: Install piston rings in the following
order:
Fig. 2 Checking Cylinder Bore Size
CYLINDER BORE AND PISTON
SPECIFICATION CHART
Standard Bore Maximum
Out-Of-RoundMaximum
Taper
87.5 mm 0.051 mm 0.051 mm
(3.445 in.) (0.002 in.) (0.002 in.)
Standard Piston Size
87.450 - 87.468 mm (3.4434 - 3.4441 in.)
Piston To Bore Clearance
0.024 - 0.057 mm (0.0009 - 0.0022 in.)
Note: Measurements taken at Piston Size Location.
Fig. 3 Piston Measurement
Fig. 4 Piston Ring Gap
PISTON RING SPECIFICATION CHART
Ring Position Ring Gap Wear Limit
Upper Ring 0.025 to 0.51 mm
(0.0098 to 0.020 in.)0.8 mm
(0.031 in.)
Intermediate
Ring0.23 to 0.48 mm
(0.009 to 0.018 in.)0.8 mm
(0.031 in.)
Oil Control
Ring0.25 to 0.64 mm
(0.0098 to 0.025 in.)1.0 mm
(0.039 in.)
Ring Position Groove Clearance Max.
Clearance
Upper Ring 0.030 to 0.080 mm
(0.0011 to 0.0031 in.)0.10 mm
(0.004 in.)
Intermediate
Ring0.025 to 0.065 mm
(0.0010 to 0.0026 in.)0.10 mm
(0.004 in.)
Oil Control Ring - Three Piece. Oil Ring Side Rails
Must Be Free To Rotate After Assembly.
Fig. 5 Piston Ring Side Clearance
NS2.4L ENGINE 9 - 17
SERVICE PROCEDURES (Continued)

a. Oil ring expander.
b. Upper oil ring side rail.
c. Lower oil ring side rail.
d. No. 2 Intermediate piston ring.
e. No. 1 Upper piston ring.
(2) Install the side rail by placing one end
between the piston ring groove and the expander.
Hold end firmly and press down the portion to be
installed until side rail is in position.Do not use a
piston ring expander(Fig. 7).
(3) Install upper side rail first and then the lower
side rail.
(4) Install No. 2 piston ring and then No. 1 piston
ring.
(5) Position piston ring end gaps as shown in (Fig.
8).
(6) Position oil ring expander gap at least 45É
from the side rail gaps butnoton the piston pin cen-
ter or on the thrust direction. Staggering ring gap is
important for oil control.FITTING CONNECTING ROD BEARINGS
Engine connecting rod bearing clearances can be
determined by use of Plastigage or equivalent. The
following is the recommended procedure for the use
of Plastigage:
(1) Rotate the crankshaft until the connecting rod
to be checked is at the bottom of its stroke.
(2) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(3) Place a piece of Plastigage across the entire
width of the bearing shell in the bearing cap approx-
imately 6.35 mm (1/4 in.) off center and away from
the oil hole (Fig. 9). In addition, suspect areas can be
checked by placing plastigage in the suspect area.
(4) Before assembling the rod cap with Plastigage
in place, the crankshaft must be rotated until the
connecting rod being checked starts moving toward
the top of the engine. Only then should the cap be
assembled and torqued to specifications.Do not
rotate the crankshaft while assembling the cap
or the Plastigage may be smeared, giving inac-
curate results.
(5) Remove the bearing cap and compare the width
of the flattened Plastigage (Fig. 9) with the metric
Fig. 6 Piston Ring Installation
Fig. 7 Installing Side Rail
Fig. 8 Piston Ring End Gap Position
Fig. 9 Measuring Plastigage Width
9 - 18 2.4L ENGINENS
SERVICE PROCEDURES (Continued)