Jeep XJ. Manual — part 292
INSTALLATION
(1) Inspect the engine cylinder head cover for
cracks. Replace the cover, if cracked.
NOTE: The
original
dark
grey
gasket
material
should NOT be removed. If sections of the gasket
material are missing or are compressed, replace the
engine cylinder 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.
(2) If a replacement cover is installed, transfer the
CCV valve grommet the oil filler cap from the origi-
nal cover to the replacement cover.
(3) Install engine cylinder head cover. Tighten the
mounting bolts to 13 N·m (115 in. lbs.) torque.
(4) Connect the CCV hoses (Fig. 52).
(5) Connect negative cable to battery.
(6) Install the air inlet hose and resonator.
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. (Refer
to procedure in this section)
(2) Check for rocker arm bridges which are caus-
ing misalignment of the rocker arm to valve tip area.
(3) Remove the capscrews at each bridge and pivot
assembly (Fig. 53). Alternately loosen the capscrews
one turn at a time to avoid damaging the bridges.
(4) Remove the bridges, pivots and corresponding
pairs of rocker arms (Fig. 53). 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.
(6) Clean all the components with cleaning sol-
vent.
(7) Use compressed air to blow out the oil passages
in the rocker arms and push rods.
INSTALLATION
(1) Lubricate the ball ends of the push rods with
Mopar Engine Oil Supplement, or equivalent and
install 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
Fig. 52 Engine Cylinder Head Cover
1 – AIR INLET FITTING
2 – AIR FILTER COVER
3 – FIXED ORIFICE FITTING
Fig. 53 Rocker Arm Assembly
1 – CAPSCREWS
2 – BRIDGE
3 – PIVOT ASSEMBLY
4 – PUSH RODS
5 – ROCKER ARMS
9 - 36
2.5L ENGINE
XJ
REMOVAL AND INSTALLATION (Continued)
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 N·m (21 ft. lbs.)
torque.
(5) Install the engine cylinder head cover.
VALVE SPRING AND SEAL
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. Refer
to procedure in this section.
(2) Remove cap screws, bridge and pivot assem-
blies 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
Compressor Tool MD-998772A to compress the spring
and remove the locks (Fig. 54).
(9) Remove valve spring and retainer (Fig. 54).
(10) Remove valve stem oil seals (Fig. 54). Note
the valve seals are different for intake and exhaust
valves. The top of each seal is marked either INT
(intake/black in color) or EXH (exhaust/brown in
color). DO NOT mix the seals.
INSTALLATION
Inspect the valve stems, especially the grooves. An
Arkansas smooth stone should be used to remove
nicks and high spots.
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) Release air pressure and 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 cap screws alternately, one
at a time, to avoid damaging the bridge. Tighten the
cap screws to 28 N·m (21 ft. lbs.) torque.
Fig. 54 Valve and Valve Components
1 – VALVE LOCKS (3–BEAD)
2 – RETAINER
3 – VALVE STEM OIL SEAL
4 – INTAKE VALVE
5 – EXHAUST VALVE
6 – VALVE SPRING
XJ
2.5L ENGINE
9 - 37
REMOVAL AND INSTALLATION (Continued)
(9) Install the engine cylinder head cover.
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. (Refer
to procedure in this section)
(5) Remove the capscrews, bridge and pivot assem-
blies and rocker arms (Fig. 55).
(6) Remove the push rods (Fig. 55). Retain the
push rods, bridges, pivots and rocker arms in
the same order as removed.
(7) Loosen the accessory drive belt at the power
steering pump bracket, if equipped or at the idler
pulley bracket (refer to Group 7, Cooling System for
the proper procedure).
(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.
(9) If equipped, disconnect the power steering
pump bracket. Set the pump and bracket aside. DO
NOT disconnect the hoses.
(10) Perform
fuel
pressure
release
procedure
(Refer to Group 14, fuel systems for proper proce-
dures).
(11) Remove the latch clip and disconnect the fuel
supply hose.
(12) 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).
(13) Number and disconnect the ignition wires and
remove the spark plugs.
(14) Disconnect the coolant temperature sending
unit connector.
(15) Remove the engine cylinder head bolts.
(16) Remove the engine cylinder head and gasket
(Fig. 56).
(17) If this was the first time the bolts were
removed, 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 cyl-
inder bores.
NOTE: If valves, springs, or seals are to be inspect-
ed/replaced at this time, refer to Valves and Valve
Springs later in this section for proper inspection
procedures.
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
diameter. 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.
Fig. 55 Rocker Arm Assembly
1 – CAPSCREWS
2 – BRIDGE
3 – PIVOT ASSEMBLY
4 – PUSH RODS
5 – ROCKER ARMS
9 - 38
2.5L ENGINE
XJ
REMOVAL AND INSTALLATION (Continued)
(1) Fabricate two engine cylinder head alignment
dowels from used head bolts (Fig. 57). Use the long-
est 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. 58).
(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.
CAUTION: Engine cylinder head bolts should be
reused only once. Replace the head bolts if they
were used before or if they have a paint dab on the
top of the bolt.
(6) Coat the threads of bolt No.7, only, with Loctite
PST sealant or equivalent.
(7) Install all head bolts, except No.8 and No.10.
(8) Remove the dowels.
(9) Install No.8 and No.10 head bolts.
CAUTION: During the final tightening sequence,
bolt No.7 will be tightened to a lower torque than
the rest of the bolts. DO NOT overtighten bolt No.7.
(10) Tighten the engine cylinder head bolts in
sequence according to the following procedure (Fig.
59) :
(a) Tighten all bolts in sequence (1 through 10)
to 30 N·m (22 ft. lbs.) torque.
(b) Tighten all bolts in sequence (1 through 10)
to 61 N·m (45 ft. lbs.) torque.
(c) Check all bolts to verify they are set to 61
N·m (45 ft. lbs.) torque.
(d) Tighten bolts (in sequence):
• Bolts 1 through 6 to 149 N·m (110 ft. lbs.)
torque.
• Bolt 7 to 136 N·m (100 ft. lbs.) torque.
• Bolts 8 through 10 to 149 N·m (110 ft. lbs.)
torque.
(e) Check all bolts in sequence to verify the cor-
rect torque.
(f) If not already done, clean and mark each bolt
with a dab of paint after tightening. Should you
encounter bolts which were painted in an earlier
service operation, replace them.
(11) Connect the coolant temperature sending unit
connector.
(12) Install the spark plugs and tighten to 37 N·m
(27 ft. lbs.) torque. Connect the ignition wires.
Fig. 56 Engine Cylinder Head Assembly
1 – BRIDGE
2 – PIVOT ASM.
3 – ROCKER ARM
4 – CYLINDER HEAD
5 – HEAD GASKET
6 – PUSH ROD
Fig. 57 Fabricate Alignment Dowels
1 – USED CYLINDER HEAD BOLT
2 – SLOT
Fig. 58 Alignment Dowel Locations
1 – ALIGNMENT DOWEL
2 – ALIGNMENT DOWEL
XJ
2.5L ENGINE
9 - 39
REMOVAL AND INSTALLATION (Continued)
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