lock JEEP CHEROKEE 1995 Service Repair Manual

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.
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 ac-
cording 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.
Refer to the Cylinder Combustion Pressure Leak-
age Test Diagnosis chart.
INSPECTION (ENGINE OIL LEAKS IN GENERAL)
Begin with a through visual inspection of the en-
gine, particularly at the area of the suspected leak. If
an oil leak source is not readily identifiable, the fol-
lowing 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 ap-
proximately 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, re-
pair per service manual instructions.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24km (15 miles), and
repeat step (3).
If the oil leak source is not positively identi-
fied at this time, proceed with the air leak detec-
tion test method as follows:
(1) Disconnect the breather cap to air cleaner hose
at the breather cap end. Cap or plug breather cap
nipple.
(2) Remove the PCV valve from the cylinder head
cover. Cap or plug the PCV valve grommet.
(3) 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.
(4) 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 de-
tected and identified, repair per service manual pro-
cedures.
(5) If the leakage occurs at the 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
and remove the air hose and all plugs and caps. In-
stall the PCV valve and breather cap hose. Proceed
to step 7.
(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.
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 en-
gine, a more involved inspection is necessary. The fol-
lowing 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:
(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, distributor seal,
camshaft bore cup plugs oil galley pipe plugs, oil
9 - 6 ENGINESJ

filter runoff, and main bearing cap to cylinder
block mating surfaces. See Group 9, Engines for
proper repair procedures of 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 de-
tected between the crankshaft and seal while slowly
turning the crankshaft, it is possible the crankshaft
seal surface is damaged. The seal area on the crank-
shaft 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 ro-
tation, no further inspection can be done until disas-
sembled. Refer to the service DiagnosisÐMechanical,
under the Oil Leak row for components inspections
on possible causes and corrections.
(7) After the oil leak root cause and appropriate
corrective action have been identified, Refer to Group
9, EnginesÐCrankshaft Rear Oil Seals, for proper re-
placement procedures.
ENGINE OIL PRESSURE
(1) Remove oil pressure sending unit.
(2) Install Oil Pressure Line and Gauge Tool
C-3292. Start engine and record pressure. Refer to
Oil Pressure in Engine Specifications for the proper
pressures.
CYLINDER COMBUSTION PRESSURE LEAKAGE TEST DIAGNOSIS
JENGINES 9 - 7

2.5L ENGINE SERVICE PROCEDURES
INDEX
page page
Camshaft............................... 32
Camshaft Pin Replacement.................. 34
Engine AssemblyÐXJ Vehicles............... 18
Engine AssemblyÐYJ Vehicles............... 20
Engine Cylinder Head...................... 25
Engine Cylinder Head Cover................. 22
Engine Damper........................... 17
Engine MountÐRear....................... 16
Engine MountsÐFront..................... 14
General Information....................... 13
Hydraulic Tappets......................... 24OilPan ................................. 36
Rocker Arms and Push Rods................ 23
Timing Case Cover........................ 31
Timing Case Cover Oil Seal Replacement....... 30
Timing Chain and Sprockets................. 31
Valve Component ReplaceÐCylinder Head Not
Removed.............................. 23
Valve Springs and Oil Seals................. 23
Valve Timing............................. 30
Valves and Valve Springs................... 27
Vibration Damper......................... 30
GENERAL INFORMATION
The 2.5 liter (150 CID) four-cylinder engine is an
In-line, lightweight, overhead valve engine (Fig. 1).
This engine is designed for unleaded fuel.
The engine cylinder head has dual quench-type
combustion chambers that create turbulence and fast
burning of the air/fuel mixture. This results in good
fuel economy.
The cylinders are numbered 1 through 4 from front
to rear. The firing order is 1-3-4-2 (Fig. 2).
The crankshaft rotation is clockwise, when viewed
from the front of the engine. The crankshaft rotates
within five main bearings and the camshaft rotates
within four bearings.
BUILD DATE CODE
The engine Build Date Code is located on a ma-
chined surface on the right side of the cylinder block
between the No.3 and No.4 cylinders (Fig. 3).
Fig. 1 Engine Description
Fig. 2 Engine Firing Order
Fig. 3 Build Date Code Location
J2.5L ENGINE 9 - 13

The digits of the code identify:
(1) 1st DigitÐThe year (4 = 1994).
(2) 2nd & 3rd DigitsÐThe month (01 - 12).
(3) 4th & 5th DigitsÐThe engine type/fuel system/
compression ratio (HX = A 2.5 liter (150 CID) 9.1:1
compression ratio engine with a multi-point fuel in-
jection system).
(4) 6th & 7th DigitsÐThe day of engine build (01 -
31).
FOR EXAMPLE:Code * 401HX23 * identifies a
2.5 liter (150 CID) engine with a multi-point fuel in-
jection system, 9.1:1 compression ratio and built on
January 23, 1994.
OVERSIZE AND UNDERSIZE COMPONENT
CODES
Some engines may be built with oversize or under-
size components such as:
²Oversize cylinder bores.
²Oversize camshaft bearing bores.
²Undersize crankshaft main bearing journals.
²Undersize connecting rod journals.
These engines are identified by a letter code (Fig.
4) stamped on the oil filter boss near the distributor
(Fig. 5).
ENGINE MOUNTSÐFRONT
The front mounts support the engine at each side.
These supports are made of resilient rubber.
REMOVALÐXJ VEHICLES
(1) Disconnect negative cable from battery.
(2) Raise the vehicle.
(3) Support the engine.
(4) Remove through bolt nut (Fig. 6). DO NOT re-
move the through bolt.
(5) Remove the retaining bolts and nuts from the
support cushions (Fig. 6).
(6) Remove the through bolt.
(7) Remove the support cushions.
INSTALLATIONÐXJ VEHICLES
(1) If the engine support bracket was removed, po-
sition the LEFT bracket (Fig. 6) and the RIGHT
bracket with generator brace (Fig. 7) onto the cylin-
der block. Install the bolts and stud nuts.
(a) RIGHT SIDE (Fig. 7)ÐTighten the bolts to 61
Nzm (45 ft. lbs.) torque. Tighten the stud nuts to 46
Nzm (34 ft. lbs.) torque.
(b) LEFT SIDE (Fig. 6)ÐTighten the bolts to 61
Nzm (45 ft. lbs.) torque.
(2) If the support cushion brackets were removed,
position the brackets onto the lower front sill (Figs. 6
and 8). Install the bolts and stud nuts. Tighten the
bolts to 54 Nzm (40 ft. lbs.) torque and the stud nuts
to 41 Nzm (30 ft. lbs.) torque.
(3) Place the support cushions onto the support
cushion brackets (Fig. 6). Tighten the right support
cushion nuts to 65 Nzm (48 ft. lbs.) torque. Tighten
the left support cushion bolt and nut to 41 Nzm (30
ft. lbs.) torque.
Fig. 4 Oversize and Undersize Component Codes
Fig. 5 Oversize and Undersize Component Code
Location
9 - 14 2.5L ENGINEJ

INSTALLATIONÐYJ VEHICLES
(1) If the engine support bracket was removed, po-
sition the bracket onto the block and install the at-
taching bolts (Fig. 9). Tighten the bolts to 62 Nzm (46
ft. lbs.) torque.
(2) Place the support cushion on the support cush-
ion bracket (Fig. 9). Install the support cushion re-
taining bolts and nuts. Tighten the bolts and nuts to
52 Nzm (38 ft. lbs.) torque.
(3) Install the through bolt and the retaining nut
(Fig. 9). Tighten the through bolt nut to 69 Nzm (51
ft. lbs.) torque.
(4) Remove the engine support.
(5) Lower the vehicle.
(6) Connect negative cable to battery.
ENGINE MOUNTÐREAR
A resilient rubber cushion supports the transmis-
sion at the rear between the transmission extension
housing and the rear support crossmember or skid
plate.
REMOVALÐXJ VEHICLES
(1) Disconnect negative cable from battery.
(2) Raise the vehicle and support the transmission.
(3) Remove the nuts holding the support cushion to
the crossmember (Figs. 10 and 11). Remove the cross-
member.
(4)MANUAL TRANSMISSION:
(a) Remove the support cushion nuts and remove
the cushion.
(b) If necessary, remove the bolts holding the
transmission support bracket to the transmission
(Fig. 10). Remove the bracket.
(5)AUTOMATIC TRANSMISSION:
(a) Remove the support cushion bolts and remove
the cushion and the transmission support bracket.(b) If necessary on 2WD vehicles, remove the
bolts holding the transmission support adaptor
bracket to the transmission (Fig. 11). Remove the
adaptor bracket.
INSTALLATIONÐXJ VEHICLES
(1)MANUAL TRANSMISSION:
(a) If removed, position the transmission support
bracket to the transmission and install the bolts.
Tighten the bolts to 43 Nzm (32 ft. lbs.) torque.
(b) Position the support cushion onto the trans-
mission support bracket. Install and tighten the
nuts to 46 Nzm (34 ft. lbs.) torque.
(2)AUTOMATIC TRANSMISSION:
(a) If removed, position the transmission support
adaptor bracket (2WD vehicles) to the transmission
and install the bolts. Tighten the bolts to 75 Nzm
(55 ft. lbs.) torque.
(b) Position the transmission support bracket
and support cushion to the transmission and install
the bolts. Tighten the bolts to 75 Nzm (55 ft. lbs.)
torque.
(3) Position the crossmember onto the support
cushion studs and install the nuts. Tighten the nuts
to 22 Nzm (192 in. lbs.) torque.
(4) Install the crossmember to sill bolts and
tighten to 41 Nzm (30 ft. lbs.) torque.
Fig. 10 Rear MountÐXJ Vehicles (Manual
Transmission)
Fig. 11 Rear MountÐXJ Vehicles (Automatic
Transmission)
9 - 16 2.5L ENGINEJ

(14) Install the remaining flywheel housing bolts.
Tighten the bolts to 38 Nzm (28 ft. lbs.) torque.
(15) Install the starter motor and connect the ca-
ble. Tighten the bolts to 45 Nzm (33 ft. lbs.) torque.
(16) Install the oil filter.
(17) Lower the vehicle.
(18) Connect the coolant hoses and tighten the
clamps.
(19) If equipped with power steering:
(a) Remove the protective caps
(b) Connect the hoses to the fittings at the steer-
ing gear. Tighten the nut to 52 Nzm (38 ft. lbs.)
torque.
(c) Fill the pump reservoir with fluid.
(20) Remove the pulley-to-water pump flange
alignment capscrew and install the fan and spacer or
Tempatrol fan assembly.
(21) Tighten the serpentine drive belt according to
the specifications listed in Group 7, Cooling System.
(22) Install the fan shroud and radiator.
(23) Connect the radiator hoses.
(24) Connect the heater hoses.
(25) Connect the throttle valve rod and retainer.
(26) Connect the throttle cable and install the rod.
(27) Install the throttle valve rod spring.
(28) Connect the speed control cable, if equipped.
(29) Connect the oxygen sensor wire connector.
(30) Install the vacuum hose and check valve on
the brake booster.
(31) Connect the coolant temperature sensor wire
connector.
(32) Connect the idle speed actuator wire connec-
tor.
(33) Connect the fuel inlet and return hoses at the
fuel rail. Verify that the quick-connect fitting assem-
bly fits securely over the fuel lines by giving the fuel
lines a firm tug.
(34) Install the fuel line bracket to the intake man-
ifold.
(35) Connect all fuel injection wire connections.
(36) Install the engine ground strap.
(37) Connect the ignition coil wire connector.
(38) Remove the coolant temperature sending unit
to permit air to escape from the block. Fill the cool-
ing system with coolant. Install the coolant tempera-
ture sending unit when the system is filled.
(39) Install the battery and connect the battery ca-
bles.
(40) Install the air cleaner bonnet to the throttle
body.
(41) Install the air cleaner.
(42) Lower the hood and secure in place.
(43) Start the engine and inspect for leaks.
(44) Stop the engine and check the fluid levels.
Add fluid, as required.ENGINE CYLINDER HEAD COVER
A cured gasket is part of the engine cylinder head
cover.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect the Crankcase Ventilation (CCV)
vacuum hose from engine cylinder head cover (Fig.
1).
(3) Disconnect the fresh air inlet hose from the en-
gine cylinder head cover (Fig. 1).
(4) Remove the engine cylinder head cover mount-
ing bolts.
(5) Remove the engine cylinder head cover.
CLEANING
Remove any original sealer from the cover sealing
surface of the engine cylinder head and clean the
surface using a fabric cleaner.
Remove all residue from the sealing surface using
a clean, dry cloth.
INSPECTION
Inspect the engine cylinder head cover for cracks.
Replace the cover, if cracked.
The original dark grey gasket material should NOT
be removed. If sections of the gasket material are
missing or are compressed, replace the engine cylin-
der head cover. However, sections with minor damage
such as small cracks, cuts or chips may be repaired
with a hand held applicator. The new material must
be smoothed over to maintain gasket height. Allow
the gasket material to cure prior to engine cylinder
head cover installation.
INSTALLATION
(1) If a replacement cover is installed, transfer the
CCV valve grommet the oil filler cap from the origi-
nal cover to the replacement cover.
(2) Install engine cylinder head cover. Tighten the
mounting bolts to 10 Nzm (85 in. lbs.) torque.
Fig. 1 Engine Cylinder Head Cover
9 - 22 2.5L ENGINEJ

(3) Connect the CCV hoses (Fig. 1).
(4) Connect negative cable to battery.
VALVE COMPONENT REPLACEÐCYLINDER HEAD
NOT REMOVED
ROCKER ARMS AND PUSH RODS
This procedure can be done with the engine in or
out of the vehicle.
REMOVAL
(1) Remove the engine cylinder head cover.
(2) Remove the capscrews at each bridge and pivot
assembly (Fig. 2). Alternately loosen the capscrews
one turn at a time to avoid damaging the bridges.
(3) Check for rocker arm bridges which are causing
misalignment of the rocker arm to valve tip area.
(4) Remove the bridges, pivots and corresponding
pairs of rocker arms (Fig. 2). Place them on a bench
in the same order as removed.
(5) Remove the push rods and place them on a
bench in the same order as removed.
CLEANING
Clean all the components with cleaning solvent.
Use compressed air to blow out the oil passages in
the rocker arms and push rods.
INSPECTION
Inspect the pivot surface area of each rocker arm.
Replace any that are scuffed, pitted, cracked or ex-
cessively worn.
Inspect the valve stem tip contact surface of each
rocker arm and replace any rocker arm that is deeply
pitted.Inspect each push rod end for excessive wear and
replace as required. If any push rod is excessively
worn because of lack of oil, replace it and inspect the
corresponding hydraulic tappet for excessive wear.
Inspect the push rods for straightness by rolling
them on a flat surface or by shining a light between
the push rod and the flat surface.
A wear pattern along the length of the push rod is
not normal. Inspect the engine cylinder head for ob-
struction if this condition exists.
INSTALLATION
(1) Lubricate the ball ends of the push rods with
Mopar Engine Oil Supplement, or equivalent and in-
stall push rods in their original locations. Ensure
that the bottom end of each push rod is centered in
the tappet plunger cap seat.
(2) Using Mopar Engine Oil Supplement, or equiv-
alent, lubricate the area of the rocker arm that the
pivot contacts. Install rocker arms, pivots and bridge
above each cylinder in their original position.
(3) Loosely install the capscrews through each
bridge.
(4) At each bridge, tighten the capscrews alter-
nately, one turn at a time, to avoid damaging the
bridge. Tighten the capscrews to 28 Nzm (21 ft. lbs.)
torque.
(5) Install the engine cylinder head cover.
VALVE SPRINGS AND OIL SEALS
This procedure can be done with the engine cylin-
der head installed on the block.
REMOVAL
Each valve spring is held in place by a retainer and
a set of conical valve locks. The locks can be removed
only by compressing the valve spring.
(1) Remove the engine cylinder head cover.
(2) Remove capscrews, bridge and pivot assemblies
and rocker arms for access to each valve spring to be
removed.
(3) Remove push rods. Retain the push rods,
bridges, pivots and rocker arms in the same order
and position as removed.
(4) Inspect the springs and retainer for cracks and
possible signs of weakening.
(5) Remove the spark plug(s) adjacent to the cylin-
der(s) below the valve springs to be removed.
(6) Install a 14 mm (1/2 inch) (thread size) air hose
adaptor in the spark plug hole.
(7) Connect an air hose to the adapter and apply
air pressure slowly. Maintain at least 621 kPa (90
psi) of air pressure in the cylinder to hold the valves
against their seats. For vehicles equipped with an air
conditioner, use a flexible air adaptor when servicing
the No.1 cylinder.
(8) Tap the retainer or tip with a rawhide hammer
to loosen the lock from the retainer. Use Valve Spring
Fig. 2 Rocker Arm Assembly
J2.5L ENGINE 9 - 23

Compressor Tool MD-998772A to compress the spring
and remove the locks (Fig. 7).
(9) Remove valve spring and retainer (Fig. 7).
(10) Remove valve stem oil seals (Fig. 7). Note the
valve seals are different for intake and exhaust
valves. The top of each seal is marked either INT (In-
take) or EXH (Exhaust). DO NOT mix the seals.
INSPECTION
Inspect the valve stems, especially the grooves. An
Arkansas smooth stone should be used to remove
nicks and high spots.
INSTALLATION
CAUTION: Install oil seals carefully to prevent dam-
age from the sharp edges of the valve spring lock
grove.
(1) Lightly push the valve seal over the valve stem
and valve guide boss. Be sure the seal is completely
seated on the valve guide boss.
(2) Install valve spring and retainer.
(3) Compress the valve spring with Valve Spring
Compressor Tool MD-998772A and insert the valve
locks. Release the spring tension and remove the
tool. Tap the spring from side-to-side to ensure that
the spring is seated properly on the engine cylinder
head.
(4) Disconnect the air hose. Remove the adaptor
from the spark plug hole and install the spark plug.
(5) Repeat the procedures for each remaining valve
spring to be removed.
(6) Install the push rods. Ensure the bottom end of
each rod is centered in the plunger cap seat of the
hydraulic valve tappet.(7) Install the rocker arms, pivots and bridge at
their original location.
(8) Tighten the bridge capscrews alternately, one
at a time, to avoid damaging the bridge. Tighten the
capscrews to 28 Nzm (21 ft. lbs.) torque.
(9) Install the engine cylinder head cover.
HYDRAULIC TAPPETS
Retain all the components in the same order as re-
moved.
REMOVAL
(1) Remove the engine cylinder head cover.
(2) Remove the bridge and pivot assemblies and
rocker arms by removing the capscrews at each
bridge. Alternately loosen each capscrew, one turn at
a time, to avoid damaging the bridges.
(3) Remove the push rods.
(4) Remove the tappets through the push rod open-
ings in the cylinder head with Hydraulic Valve Tap-
pet Removal/Installation Tool C-4129-A (Fig. 13).
CLEANING
Clean each tappet assembly in cleaning solvent to
remove all varnish, gum and sludge deposits.
INSPECTION
Inspect for indications of scuffing on the side and
base of each tappet body.
Inspect each tappet base for concave wear with a
straightedge positioned across the base. If the base is
concave, the corresponding lobe on the camshaft is
also worn. Replace the camshaft and defective tap-
pets.
Fig. 7 Valve and Valve Components
Fig. 13 Hydraulic Valve Tappet Removal/Installation
Tool C-4129-A
9 - 24 2.5L ENGINEJ

LEAK-DOWN TEST
After cleaning and inspection, test each tappet for
specified leak-down rate tolerance to ensure zero-lash
operation (Fig. 14).
Swing the weighted arm of the hydraulic valve tap-
pet tester away from the ram of the Universal Leak-
Down Tester .
(1) Place a 7.925-7.950 mm (0.312-0.313 inch) di-
ameter ball bearing on the plunger cap of the tappet.
(2) Lift the ram and position the tappet (with the
ball bearing) inside the tester cup.
(3) Lower the ram, then adjust the nose of the ram
until it contacts the ball bearing. DO NOT tighten
the hex nut on the ram.
(4) Fill the tester cup with hydraulic valve tappet
test oil until the tappet is completely submerged.
(5) Swing the weighted arm onto the push rod and
pump the tappet plunger up and down to remove air.
When the air bubbles cease, swing the weighted arm
away and allow the plunger to rise to the normal po-
sition.
(6) Adjust the nose of the ram to align the pointer
with the SET mark on the scale of the tester and
tighten the hex nut.
(7) Slowly swing the weighted arm onto the push
rod.
(8) Rotate the cup by turning the handle at the
base of the tester clockwise one revolution every 2
seconds.
(9) Observe the leak-down time interval from the
instant the pointer aligns with the START mark on
the scale until the pointer aligns with the 0.125
mark. A normally functioning tappet will require 20-
110 seconds to leak-down. Discard tappets with leak-
down time interval not within this specification.
INSTALLATION
It is not necessary to charge the tappets with en-
gine oil. They will charge themselves within a very
short period of engine operation.(1) Dip each tappet in Mopar Engine Oil Supple-
ment, or equivalent.
(2) Use Hydraulic Valve Tappet Removal/Installa-
tion Tool C-4129-A to install each tappet in the same
bore from where it was originally removed.
(3) Install the push rods in their original locations.
(4) Install the rocker arms and bridge and pivot
assemblies at their original locations. Loosely install
the capscrews at each bridge.
(5) Tighten the capscrews alternately, one turn at
a time, to avoid damaging the bridges. Tighten the
capscrews to 28 Nzm (21 ft. lbs.) torque.
(6) Pour the remaining Mopar Engine Oil Supple-
ment, or equivalent over the entire valve actuating
assembly. The Mopar Engine Oil Supplement, or
equivalent must remain with the engine oil for at
least 1 600 km (1,000 miles). The oil supplement
need not be drained until the next scheduled oil
change.
(7) Install the engine cylinder head cover.
ENGINE CYLINDER HEAD
This procedure can be done with the engine in or
out of the vehicle.
REMOVAL
(1) Disconnect negative cable from battery.
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAIN COCK WITH THE SYSTEM HOT AND PRES-
SURIZED BECAUSE SERIOUS BURNS FROM THE
COOLANT CAN OCCUR.
(2) Drain the coolant and disconnect the hoses at
the engine thermostat housing. DO NOT waste reus-
able coolant. If the solution is clean and is being
drained only to service the engine or cooling system,
drain the coolant into a clean container for reuse.
(3) Remove the air cleaner assembly.
(4) Remove the engine cylinder head cover.
(5) Remove the capscrews, bridge and pivot assem-
blies and rocker arms (Fig. 2).
(6) Remove the push rods (Fig. 2).Retain the
push rods, bridges, pivots and rocker arms in
the same order as removed.
(7) Loosen the serpentine drive belt at the power
steering pump, if equipped or at the idler pulley (re-
fer to Group 7, Cooling System for the proper proce-
dure).
(8) If equipped with air conditioning, perform the
following:
(a) Remove the bolts from the A/C compressor
mounting bracket and set the compressor aside.
(b) Remove the air conditioner compressor
bracket bolts from the engine cylinder head.
(c) Loosen the through bolt at the bottom of the
bracket.
Fig. 14 Leak-Down Tester
J2.5L ENGINE 9 - 25

(9) If equipped, disconnect the power steering
pump bracket. Set the pump and bracket aside. DO
NOT disconnect the hoses.
(10) Remove the fuel lines and vacuum advance
hose.
(11) Remove the intake and engine exhaust mani-
folds from the engine cylinder head (refer to Group
11, Exhaust System and Intake Manifold for the
proper procedures).
(12) Disconnect the ignition wires and remove the
spark plugs.
(13) Disconnect the temperature sending unit wire
connector.
(14) Remove the ignition coil and bracket assem-
bly.
(15) Remove the engine cylinder head bolts.
(16) Remove the engine cylinder head and gasket
(Fig. 3).
(17) If this was the first time the bolts were re-
moved, put a paint dab on the top of the bolt. If the
bolts have a paint dab on the top of the bolt or it
isn't known if they were used before, discard the
bolts.
(18) Stuff clean lint free shop towels into the cylin-
der bores.
CLEANING
Thoroughly clean the engine cylinder head and cyl-
inder block mating surfaces. Clean the intake and ex-
haust manifold and engine cylinder head mating
surfaces. Remove all gasket material and carbon.
Check to ensure that no coolant or foreign material
has fallen into the tappet bore area.
Remove the carbon deposits from the combustion
chambers and top of the pistons.
INSPECTION
Use a straightedge and feeler gauge to check the
flatness of the engine cylinder head and block mating
surfaces.
INSTALLATION
The engine cylinder head gasket is a composition
gasket. The gasket is to be installed DRY.DO NOT
use a gasket sealing compound on the gasket.
If the engine cylinder head is to be replaced and
the original valves used, measure the valve stem di-
ameter. Only standard size valves can be used with a
service replacement engine cylinder head unless the
replacement head valve stem guide bores are reamed
to accommodate oversize valve stems. Remove all
carbon buildup and reface the valves.
(1) Fabricate two engine cylinder head alignment
dowels from used head bolts (Fig. 4). Use the longest
head bolt. Cut the head of the bolt off below the hex
head. Then cut a slot in the top of the dowel to allow
easier removal with a screwdriver.
(2) Install one dowel in bolt hole No.10 and the
other dowel in bolt hole No.8 (Fig. 5).
(3) Remove the shop towels from the cylinder
bores. Coat the bores with clean engine oil.
(4) Place the engine cylinder head gasket (with the
numbers facing up) over the dowels.
(5) Place the engine cylinder head over the dowels.
Fig. 3 Engine Cylinder Head Assembly
Fig. 4 Fabricate Alignment Dowels
Fig. 5 Alignment Dowel Locations
9 - 26 2.5L ENGINEJ