1995 JEEP YJ check engine

FITTING (CRANKSHAFT INSTALLED)
The main bearing caps, numbered (front to rear)
from 1 through 5 have an arrow to indicate the for-
ward position. The upper main bearing inserts are
grooved to provide oil channels while the lower in-
serts are smooth.
Each bearing insert pair is selectively fitted to its
respective journal to obtain the specified operating
clearance. In production, the select fit is obtained by
using various-sized color-coded bearing insert pairs
as listed in the Main Bearing Fitting Chart. The
bearing color code appears on the edge of the insert.
The size is not stamped on bearing inserts used
for engine production.
The main bearing journal size (diameter) is identi-
fied by a color-coded paint mark on the adjacent
cheek. The rear main journal, is identified by a color-
coded paint mark on the crankshaft rear flange.
When required, upper and lower bearing inserts of
different sizes may be used as a pair. A standard size
insert is sometimes used in combination with a 0.025
mm (0.001 inch) undersize insert to reduce the clear-
ance by 0.013 mm (0.0005 inch).Never use a pair
of bearing inserts with greater than a 0.025 mm
(0.001 inch) difference in size (Fig. 4).
When replacing inserts, the odd size inserts
must be either all on the top (in cylinder block)
or all on the bottom (in main bearing cap).
Once the bearings have been properly fitted, pro-
ceed to Crankshaft Main BearingÐInstallation.
BEARING-TO-JOURNAL CLEARANCE (CRANKSHAFT
INSTALLED)
When using Plastigage, check only one bearing
clearance at a time.
Install the grooved main bearings into the cylinder
block and the non-grooved bearings into the bearing
caps.
Install the crankshaft into the upper bearings dry.
Place a strip of Plastigage across full width of the
crankshaft journal to be checked.
Install the bearing cap and tighten the bolts to 108
Nzm (80 ft. lbs.) torque.DO NOT rotate the crankshaft. This will
cause the Plastigage to shift, resulting in an in-
accurate reading. Plastigage must not be per-
mitted to crumble. If brittle, obtain fresh stock.
Remove the bearing cap. Determine the amount of
clearance by measuring the width of the compressed
Plastigage with the scale on the Plastigage envelope
(Fig. 5). Refer to Engine Specifications for the proper
clearance.
Plastigage should indicate the same clearance
across the entire width of the insert. If clearance var-
ies, it may indicate a tapered journal or foreign ma-
terial trapped behind the insert.
If the specified clearance is indicated and there are
no abnormal wear patterns, replacement of the bear-
ing inserts is not necessary. Remove the Plastigage
from the crankshaft journal and bearing insert. Pro-
ceed to Crankshaft Main BearingÐInstallation.
If the clearance exceeds specification, install a pair
of 0.025 mm (0.001 inch) undersize bearing inserts
and measure the clearance as described in the previ-
ous steps.
The clearance indicated with the 0.025 mm (0.001
inch) undersize insert pair installed will determine if
this insert size or some other combination will pro-
vide the specified clearance.
FOR EXAMPLE:If the clearance was 0.0762 mm
(0.003 inch) originally, a pair of 0.0254 mm (0.001
inch) undersize inserts would reduce the clearance by
0.0254 mm (0.001 inch). The clearance would then be
0.0508 mm (0.002 inch) and within the specification.
A 0.051 mm (0.002 inch) undersize bearing insert
and a 0.0254 mm (0.001 inch) undersize insert would
reduce the original clearance an additional 0.0127
mm (0.0005 inch). The clearance would then be
0.0381 mm (0.0015 inch).
CAUTION: Never use a pair of inserts that differ
more than one bearing size as a pair.
Fig. 4 Bearing Insert Pairs
Fig. 5 Measuring Bearing Clearance with Plastigage
9 - 46 2.5L ENGINEJ

FOR EXAMPLE:DO NOT use a standard size up-
per insert and a 0.051 mm (0.002 inch) undersize
lower insert.
If the clearance exceeds specification using a pair
of 0.051 mm (0.002 inch) undersize bearing inserts,
measure crankshaft journal diameter with a mi-
crometer. If the journal diameter is correct, the
crankshaft bore in the cylinder block may be mis-
aligned, which requires cylinder block replacement or
machining to true bore.
If journals 1 through 5 diameters are less than
63.4517 mm (2.4981 inches), replace crankshaft or
grind crankshaft down to accept the appropriate un-
dersize bearing inserts.
Once the proper clearances have been obtained,
proceed to Crankshaft Main BearingÐInstallation.
MAIN BEARING JOURNAL DIAMETER (CRANKSHAFT
REMOVED)
Remove the crankshaft from the cylinder block (re-
fer to Cylinder Block - Disassemble).
Clean the oil off the main bearing journal.
Determine the maximum diameter of the journal
with a micrometer. Measure at two locations 90É
apart at each end of the journal.
The maximum allowable taper and out of round is
0.013 mm (0.0005 inch). Compare the measured di-
ameter with the journal diameter specification (Main
Bearing Fitting Chart). Select inserts required to ob-
tain the specified bearing-to-journal clearance.
Once the proper clearances have been obtained,
proceed to Crankshaft Main BearingÐInstallation.
INSTALLATION
(1) Lubricate the bearing surface of each insert
with engine oil.
(2) Loosen all the main bearing caps. Install the
main bearing upper inserts.
(3) Install the lower bearing inserts into the main
bearing caps.
(4) Install the main bearing cap(s) and lower in-
sert(s).
(5) Clean the rear main bearing cap (No.5) mating
surfaces.
(6) Apply Loctite 518, or equivalent on the rear
bearing cap (Fig. 6). The bead should be 3 mm (0.125
in) thick. DO NOT apply Loctite 518, or equivalent to
the lip of the seal.
(7) Install the rear main bearing cap. DO NOT
strike the cap more than twice for proper engage-
ment.
(8) Tighten the bolts of caps 1, 3, 4 and 5 to 54
Nzm (40 ft. lbs.) torque. Now tighten these bolts to 95
Nzm (70 ft. lbs.) torque. Finally, tighten these bolts to
108 Nzm (80 ft. lbs.) torque.
(9) Push the crankshaft forward and backward.
Load the crankshaft front or rear and tighten cap
bolt No.2 to 54 Nzm (40 ft. lbs.) torque. Then tightento 95 Nzm (70 ft. lbs.) torque and finally tighten to
108 Nzm (80 ft. lbs.) torque.
(10) Rotate the crankshaft after tightening each
main bearing cap to ensure the crankshaft rotates
freely.
(11) Check crankshaft end play. Crankshaft end
play is controlled by the thrust bearing which is
flange and installed at the No.2 main bearing posi-
tion.
(a) Attach a magnetic base dial indicator to the
cylinder block at either the front or rear of the en-
gine.
(b) Position the dial indicator rod so that it is
parallel to the center line of the crankshaft.
(c) Pry the crankshaft forward, position the dial
indicator to zero.
(d) Pry the crankshaft forward and backward.
Note the dial indicator readings. End play is the
difference between the high and low measurements
(Fig. 7). Correct end play is 0.038-0.165 mm
(0.0015-0.0065 inch). The desired specifications are
0.051-0.064 mm (0.002-0.0025 inch).
(e) If end play is not within specification, inspect
crankshaft thrust faces for wear. If no wear is ap-
parent, replace the thrust bearing and measure
end play. If end play is still not within specifica-
tion, replace the crankshaft.
If the crankshaft was removed, install the crank-
shaft into the cylinder block (refer to Cylinder Block -
Assemble).
(12) Install the oil pan.
Fig. 6 Location of Loctite 518 (or equivalent)
J2.5L ENGINE 9 - 47

(6) Remove upper radiator support retaining bolts
and remove radiator support.
(7) Remove the fan shroud (Fig. 13) and electric
cooling fan.
(8) Disconnect the transmission fluid cooler tubing
(automatic transmission).
(9) Disconnect radiator fan switch wire connector.
(10)Vehicles with Air Conditioning:
(a) Discharge the A/C condenser.
(b) Remove the service valves and cap the com-
pressor ports.
(11) Remove the radiator or radiator and con-
denser (if equipped with A/C).
(12) Remove the fan assembly from the idler pul-
ley.
(13) Disconnect the heater hoses at the engine
thermostat housing and water pump (Figs. 13 and
14).
(14) Disconnect the throttle linkages (Fig. 15).
(15) Disconnect the speed control cable (if
equipped)Ð(Fig. 15).(16) Disconnect the line pressure cable (if equipped
with automatic transmission).
(17) Disconnect injection system wire harness con-
nector at the dash panel.
(18) Disconnect the distributor electrical connec-
tion and the oil pressure switch connector.
(19) Perform the Fuel System Pressure Release
procedure (refer to Group 14, Fuel System).
(20) Disconnect the quick-connect fuel lines at the
fuel rail and return line by squeezing the two retain-
ing tabs against the fuel tube (Fig. 15). Pull the fuel
tube and retainer from the quick-connect fitting (re-
fer to Group 14, Fuel System for the proper proce-
dure).
(21) Remove the fuel line bracket from the intake
manifold.
(22) Remove the air cleaner assembly (Fig. 16).
(23) Remove the power brake vacuum check valve
from the booster, if equipped.
(24) If equipped with power steering (Fig. 16):
(a) Disconnect the hoses from the fittings at the
steering gear.
(b) Drain the pump reservoir.
(c) Cap the fittings on the hoses and steering
gear to prevent foreign objects from entering the
system.
(25) Identify, tag and disconnect all necessary wire
connectors and vacuum hoses.
(26) Raise and support the vehicle.
(27) Disconnect the wires from the starter motor
solenoid.
(28) Remove the starter motor.
Fig. 13 Upper Radiator Hose, Coolant Recovery
Hose, Fan Shroud & Heater hoses
Fig. 14 Heater Hoses (RH Drive Vehicle)
Fig. 15 Accelerator Cable, Speed Control Cable,
Automatic Transmission Control Cable & Quick-
Connect Fuel Lines
9 - 60 4.0L ENGINEJ

(29) Disconnect the exhaust pipe from the mani-
fold.
(30) Disconnect the engine speed sensor wire con-
nection.
(31) Remove the exhaust pipe support.
(32) Remove the flywheel and converter housing
access cover.
(33)Vehicles with Automatic Transmission:
(a) Mark the converter and drive plate location.
(b) Remove the converter-to-drive plate bolts.
(34) Remove the upper flywheel and converter
housing bolts and loosen the bottom bolts.
(35) Remove the engine mount cushion-to-engine
compartment bracket bolts.
(36) Lower the vehicle.
(37) Attach a lifting device to the engine.
(38) Raise the engine off the front supports.
(39) Place a support or floor jack under the con-
verter (or flywheel) housing.
(40) Remove the remaining converter (or flywheel)
housing bolts.
(41) Lift the engine out of the engine compart-
ment.
INSTALLATION
CAUTION: When installing the engine into a vehicle
equipped with an automatic transmission, be care-
ful not to damage the trigger wheel on the flywheel.
(1) Attach a lifting device to the engine and lower
the engine into the engine compartment. For easier
installation, it may be necessary to remove the en-
gine mount cushions from the engine mount bracket
as an aide in alignment of the engine to the trans-
mission.
(2)Vehicles with Manual Transmission:
(a) Insert the transmission shaft into the clutch
spline.
(b) Align the flywheel housing with the engine.(c) Install and tighten the flywheel housing lower
bolts finger tight.
(3)Vehicles with Automatic Transmission:
(a) Align the transmission torque converter hous-
ing with the engine.
(b) Loosely install the converter housing lower
bolts and install the next higher bolt and nut on
each side.
(c) Tighten all 4 bolts finger tight.
(4) Install the engine mount cushions (if removed).
(5) Lower the engine and engine mount cushions
onto the engine compartment brackets. Install the
bolts and finger tighten the nuts.
(6) Remove the engine lifting device.
(7) Raise and support the vehicle.
(8) Install the remaining flywheel and converter
housing bolts. Tighten all bolts to 38 Nzm (28 ft. lbs.)
torque.
(9)Vehicles with Automatic Transmission:
(a) Install the converter-to-drive plate bolts.
(b) Ensure the installation reference marks are
aligned.
(10) Install the flywheel and converter housing ac-
cess cover.
(11) Install the exhaust pipe support and tighten
the screw.
(12) Tighten the engine mount-to-bracket bolts.
(13) Connect the engine speed sensor wire connec-
tions and tighten the screws.
(14) Connect the exhaust pipe to the manifold.
(15) Install the starter motor and connect the ca-
ble.
(16) Connect the wires to the starter motor sole-
noid.
(17) Lower the vehicle.
(18) Connect all the vacuum hoses and wire con-
nectors identified during engine removal.
(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) Install the power brake vacuum check valve to
the booster, if equipped.
(21) 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.
(22) Install the fuel line bracket to the intake man-
ifold.
(23) Connect the distributor electrical connector
and oil pressure switch connector.
(24) Connect the injection system wire harness
connector on the dash panel.
(25) Connect the line pressure cable (if equipped
with automatic transmission).
Fig. 16 Air Cleaner Assembly & Power Steering
Pump
J4.0L ENGINE 9 - 61

(18) Disconnect the oxygen sensor wire connector.
(19) Remove the upper radiator hose and coolant
recovery hose (Fig. 19).
(20) Disconnect lower radiator hoses at the radia-
tor.
(21) Disconnect the coolant hoses from the rear of
the intake manifold and thermostat housing.
(22) Remove the fan shroud screws.
(23) Remove the radiator attaching bolts.
(24) Remove the radiator and fan shroud (Fig. 19).
Refer to Group 7, Cooling System for the proper pro-
cedure.
(25) Remove the fan and spacer or Tempatrol fan
assembly.
(26) Install a 5/16 X 1/2-inch SAE capscrew
through fan pulley into water pump flange. This will
maintain the pulley and water pump in alignment
when crankshaft is rotated.
(27) Remove the power brake vacuum check valve
from the booster, if equipped.
(28) If equipped with power steering (Fig. 19):
(a) Disconnect the hoses from the fittings at the
steering gear.
(b) Drain the pump reservoir.
(c) Cap the fittings on the hoses and steering
gear to prevent foreign objects from entering the
system.
(29) Lift the vehicle and support it with support
stands.
(30) Remove the starter motor.
(31) Remove the flywheel housing access cover.
(32) Remove the engine support cushion-to-bracket
through bolts.
(33) Disconnect the exhaust pipe from the mani-
fold.
(34) Remove the upper flywheel housing bolts and
loosen the bottom bolts.
(35) Lower the vehicle.
(36) Attach a lifting device to the engine.(37) Raise the engine off the front supports.
(38) Place a support stand under the flywheel
housing.
(39) Remove the remaining flywheel housing bolts.
(40) Lift the engine out of the engine compartment
and install on an engine stand.
INSTALLATION
(1) Lift the engine off the stand and lower it into
the engine compartment. For easier installation, it
may be useful to remove the engine support cushions
from the engine support brackets as an aide for
alignment of the engine-to-transmission.
(2) Insert the transmission shaft into the clutch
spline.
(3) Align the flywheel housing with the engine.
(4) Install and finger tighten the flywheel housing
lower bolts.
(5) Install the engine support cushions (if re-
moved).
(6) Remove the support stand from beneath the
flywheel housing.
(7) Lower the engine and engine support cushions
onto the engine compartment brackets. Ensure that
the bolt holes are aligned. Install the bolts and
tighten the nuts.
(8) Remove the engine lifting device.
(9) Raise the vehicle.
(10) Attach the exhaust pipe to the manifold. In-
stall and tighten the nuts to 31 Nzm (23 ft. lbs.)
torque.
(11) Install the flywheel housing access cover.
(12) Install the remaining flywheel housing bolts.
Tighten the bolts to 38 Nzm (28 ft. lbs.) torque.
(13) Install the starter motor and connect the ca-
ble. Tighten the bolts to 45 Nzm (33 ft. lbs.) torque.
(14) Lower the vehicle.
(15) Connect the coolant hoses and tighten the
clamps.
Fig. 18 Fuel Line Quick-Connect Couplings, Air
Cleaner Assembly, Throttle & Speed Control CablesFig. 19 Upper Radiator Hose, Coolant Recovery
Hose, Fan Shroud & Power Steering Pump
J4.0L ENGINE 9 - 63

(16) Remove the pulley-to-water pump flange
alignment capscrew and install the fan and spacer or
Tempatrol fan assembly.
(17) Tighten the serpentine drive belt according to
the specifications listed in Group 7, Cooling System.
(18) Install the fan shroud and radiator (refer to
Group 7, Cooling System for the proper procedure).
(19) Connect the radiator hoses.
(20) Connect the throttle valve rod and retainer.
(21) Connect the throttle cable and install the rod.
(22) Install the throttle valve rod spring.
(23) Connect the speed control cable, if equipped.
(24) Connect the oxygen sensor wire connector.
(25) Install the vacuum hose and check valve on
the brake booster.
(26) Connect the coolant temperature sensor wire
connector.
(27) Connect the idle speed actuator wire connec-
tor.
(28) 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.
(29) Install the fuel line bracket to the intake man-
ifold.
(30) Connect all fuel injection wire connections.
(31) Install the engine ground strap.
(32) Connect the ignition coil wire connector.
(33) 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.
(34) 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.
(35) Install the battery and connect the battery ca-
bles.
(36) Install the air cleaner bonnet to the throttle
body.
(37) Install the air cleaner.
(38) Lower the hood and secure in place.
(39) Start the engine and inspect for leaks.
(40) 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 and oil filler cap from the origi-
nal cover to the replacement cover.
(2) Install engine cylinder head cover. Tighten the
mounting bolts to 13 Nzm (115 in. lbs.) torque.
(3) Connect the CCV hoses (Fig. 1).
(4) Connect negative cable to battery.
Fig. 1 Engine Cylinder Head Cover
9 - 64 4.0L ENGINEJ

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 excessivelyworn 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 originally 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 STEM SEAL AND SPRING REPLACEMENT
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) 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.
(7) 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. 3).
(8) Remove valve spring and retainer (Fig. 3).
Fig. 2 Rocker Arm Assembly
J4.0L ENGINE 9 - 65

(9) If equipped, disconnect the power steering
pump bracket. Set the pump and bracket aside. DO
NOT disconnect the hoses.
(10) Perform the Fuel System Pressure Release
procedure (refer to Group 14, Fuel System).
(11) Remove the fuel lines and vacuum advance
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) Disconnect the ignition wires and remove the
spark plugs.
(14) Disconnect the temperature sending unit wire
connector.
(15) Remove the ignition coil and bracket assem-
bly.
(16) Remove the engine cylinder head bolts. Bolt
No.14 cannot be removed until the head is moved for-
ward (Fig. 6). Pull bolt No.14 out as far as it will go
and then suspend the bolt in this position (tape
around the bolt).
(17) Remove the engine cylinder head and gasket
(Fig. 6).
(18) 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.
(19) 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
engine exhaust manifold and engine cylinder head
mating surfaces. Remove all gasket material and car-
bon.
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) Remove the shop towels from the cylinder
bores. Coat the bores with clean engine oil.
(2) Position the engine cylinder head gasket (with
the numbers facing up) onto the cylinder block.
CAUTION: Engine cylinder head bolts should be re-
used only once. Replace the head bolts if they were
used before or if they have a paint dab on the top
of the bolt.
(3) With bolt No.14 held in place (tape around
bolt), install the engine cylinder head. Remove the
tape from bolt No.14.
(4) Coat the threads of stud bolt No.11 with Loctite
592 sealant, or equivalent.
(5) Tighten the engine cylinder head bolts in se-
quence according to the following procedure (Fig. 7):
(a) Tighten all bolts in sequence (1 through 14)
to 30 Nzm (22 ft. lbs.) torque.
(b) Tighten all bolts in sequence (1 through 14)
to 61 Nzm (45 ft. lbs.) torque.
(c) Check all bolts to verify they are set to 61
Nzm (45 ft. lbs.) torque.
(d) Tighten bolts (in sequence):
²Bolts 1 through 10 to 149 Nzm (110 ft. lbs.) torque.
²Bolt 11 to 13 Nzm (100 ft. lbs.) torque.
²Bolts 12 through 14 to 149 Nzm (110 ft. lbs.)
torque.
CAUTION: During the final tightening sequence,
bolt No.11 will be tightened to a lower torque than
the rest of the bolts. DO NOT overtighten bolt
No.11.
(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 en-
Fig. 6 Engine Cylinder Head Assembly
9 - 68 4.0L ENGINEJ