Engine system DODGE RAM 2003 Service Repair Manual

DIAGNOSIS AND TESTINGÐCYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise, the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs (Refer to 8 - ELEC-
TRICAL/IGNITION CONTROL/SPARK PLUG -
REMOVAL).
(3) Secure the throttle in the wide-open position.
(4) Disconnect the ignition coil.
(5) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(6) Record the compression pressure on the third
revolution. Continue the test for the remaining cylin-
ders.
(Refer to 9 - ENGINE - SPECIFICATIONS) for the
correct engine compression pressures.
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing)
²Leaks between adjacent cylinders or into water
jacket²Any causes for combustion/compression pressure
loss
WARNING: DO NOT REMOVE THE RADIATOR CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM HOT 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 OFF the
engine.
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 procedure on each cylinder accord-
ing to the tester manufacturer's instructions. While
testing, listen for pressurized air escaping through
the throttle body, tailpipe or 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 CYLINDER COMBUSTION
PRESSURE LEAKAGE DIAGNOSIS CHART.
CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
AIR ESCAPES THROUGH
THROTTLE BODYIntake valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary
AIR ESCAPES THROUGH
TAILPIPEExhaust valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary
AIR ESCAPES THROUGH
RADIATORHead gasket leaking or cracked
cylinder head or blockRemove cylinder head and inspect.
Replace defective part
MORE THAN 50% LEAKAGE
FROM ADJACENT CYLINDERSHead gasket leaking or crack in
cylinder head or block between
adjacent cylindersRemove cylinder head and inspect.
Replace gasket, head, or block as
necessary
MORE THAN 25% LEAKAGE AND
AIR ESCAPES THROUGH OIL
FILLER CAP OPENING ONLYStuck or broken piston rings;
cracked piston; worn rings and/or
cylinder wallInspect for broken rings or piston.
Measure ring gap and cylinder
diameter, taper and out-of-round.
Replace defective part as necessary
DRENGINE 8.0L 9 - 359
ENGINE 8.0L (Continued)

MopartGasket Maker is an anaerobic type gasket
material. The material cures in the absence of air
when squeezed between two metallic surfaces. It will
not cure if left in the uncovered tube. The anaerobic
material is for use between two machined surfaces.
Do not use on flexible metal flanges.
MOPARtGASKET SEALANT
MopartGasket Sealant is a slow drying, perma-
nently soft sealer. This material is recommended for
sealing threaded fittings and gaskets against leakage
of oil and coolant. Can be used on threaded and
machined parts under all temperatures. This mate-
rial is used on engines with multi-layer steel (MLS)
cylinder head gaskets. This material also will pre-
vent corrosion. MopartGasket Sealant is available in
a 13 oz. aerosol can or 4oz./16 oz. can w/applicator.
FORM-IN-PLACE GASKET AND SEALER
APPLICATION
Assembling parts using a form-in-place gasket
requires care but it's easier than using precut gas-
kets.
MopartGasket Maker material should be applied
sparingly 1 mm (0.040 in.) diameter or less of sealant
to one gasket surface. Be certain the material sur-
rounds each mounting hole. Excess material can eas-
ily be wiped off. Components should be torqued in
place within 15 minutes. The use of a locating dowel
is recommended during assembly to prevent smear-
ing material off the location.
MopartEngine RTV GEN II or ATF RTV gasket
material should be applied in a continuous bead
approximately 3 mm (0.120 in.) in diameter. All
mounting holes must be circled. For corner sealing, a
3.17 or 6.35 mm (1/8 or 1/4 in.) drop is placed in the
center of the gasket contact area. Uncured sealant
may be removed with a shop towel. Components
should be torqued in place while the sealant is still
wet to the touch (within 10 minutes). The usage of a
locating dowel is recommended during assembly to
prevent smearing material off the location.
MopartGasket Sealant in an aerosol can should be
applied using a thin, even coat sprayed completely
over both surfaces to be joined, and both sides of a
gasket. Then proceed with assembly. Material in a
can w/applicator can be brushed on evenly over the
sealing surfaces. Material in an aerosol can should be
used on engines with multi-layer steel gaskets.
STANDARD PROCEDURE - REPAIR DAMAGED
OR WORN THREADS
CAUTION: Be sure that the tapped holes maintain
the original center line.Damaged or worn threads can be repaired. Essen-
tially, this repair consists of:
²Drilling out worn or damaged threads.
²Tapping the hole with a special Heli-Coil Tap, or
equivalent.
²Installing an insert into the tapped hole to bring
the hole back to its original thread size.
STANDARD PROCEDUREÐHYDROSTATIC
LOCK
CAUTION: DO NOT use the starter motor to rotate
the crankshaft. Severe damage could occur.
When an engine is suspected of hydrostatic lock
(regardless of what caused the problem), follow the
steps below.
(1) Perform the Fuel Pressure Release Procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(2) Disconnect the negative cable(s) from the bat-
tery.
(3) Inspect air cleaner, induction system, and
intake manifold to ensure system is dry and clear of
foreign material.
(4) Place a shop towel around the spark plugs to
catch any fluid that may possibly be under pressure
in the cylinder head. Remove the spark plugs.
(5) With all spark plugs removed, rotate the crank-
shaft using a breaker bar and socket.
(6) Identify the fluid in the cylinders (coolant, fuel,
oil, etc.).
(7) Be sure all fluid has been removed from the
cylinders.
(8) Repair engine or components as necessary to
prevent this problem from occurring again.
(9) Squirt a small amount of engine oil into the
cylinders to lubricate the walls. This will prevent
damage on restart.
(10) Install new spark plugs. Tighten the spark
plugs to 41 N´m (30 ft. lbs.) torque.
(11) Drain engine oil. Remove and discard the oil
filter.
(12) Install the drain plug. Tighten the plug to 34
N´m (25 ft. lbs.) torque.
(13) Install a new oil filter.
(14) Fill engine crankcase with the specified
amount and grade of oil. (Refer to LUBRICATION &
MAINTENANCE - SPECIFICATIONS).
(15) Connect the negative cable(s) to the battery.
(16) Start the engine and check for any leaks.
REMOVAL
(1) Remove the battery.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
DRENGINE 8.0L 9 - 361
ENGINE 8.0L (Continued)

(3) Discharge the air conditioning system, if
equipped (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE).
(4) Remove the upper crossmember.
(5) Remove the transmission oil cooler (Refer to 7 -
COOLING/TRANSMISSION/TRANS COOLER -
REMOVAL).
(6) Remove the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - REMOV-
AL).
(7) Remove the A/C compressor with the lines
attached (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/A/C COMPRESSOR -
REMOVAL). Set aside.
(8) If equipped, remove the condenser (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING/
A/C CONDENSER - REMOVAL).
(9) Remove the washer fluid reservoir bottle (Refer
to 8 - ELECTRICAL/WIPERS/WASHERS -
REMOVAL AND INSTALLATION).
(10) Disconnect the top radiator hose.
(11) Remove the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - REMOVAL).
(12) Remove the fan shroud.
(13) Disconnect the lower radiator hose.
(14) Disconnect the transmission cooler lines.
(15) Remove radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(16) Remove the generator with the wire connec-
tions (Refer to 8 - ELECTRICAL/CHARGING/GEN-
ERATOR - REMOVAL).
(17) Remove the air cleaner.
(18) Disconnect the throttle linkage.
(19) Remove throttle body (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/THROTTLE BODY -
REMOVAL).
(20) Remove the upper intake manifold (Refer to 9
- ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL).
(21) Remove the coil assemblies with the ignition
cables.
(22) Disconnect the heater hoses.
(23) Disconnect the power steering hoses, if
equipped.
(24) Perform the Fuel System Pressure release
procedure (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY - STANDARD PROCEDURE). Disconnect
the fuel line (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/QUICK CONNECT FITTING - STAN-
DARD PROCEDURE).
(25) On Manual Transmission vehicles, remove the
shift lever.
(26) Raise and support the vehicle on a hoist.
(27) Remove the drain plug and drain the engine
oil.
(28) Loosen front engine mount thru-bolt nuts.(29) Remove the transmission cooler line brackets
from oil pan.
(30) Disconnect exhaust pipe at manifold.
(31) Disconnect the starter wires. Remove starter
motor (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - REMOVAL).
(32) Remove transmission.
(33) Lower vehicle.
CAUTION: DO NOT lift the engine by the intake
manifold.
(34) Install an engine lifting fixture.
(35) Remove engine from vehicle and install
engine assembly on a repair stand.
INSTALLATION
(1) Remove engine from the repair stand and posi-
tion in the engine compartment. Position the thru-
bolt into the support cushion brackets.
(2) Install an engine support fixture.
(3) Raise and support the vehicle on a hoist.
(4) Install Transmission.
(5) Install the starter and connect the starter
wires (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - INSTALLATION).
(6) Install exhaust pipe to manifold.
(7) Install the transmission cooler line brackets
from oil pan.
(8) Tighten the Front mount thru-bolts and nuts to
102N´m (75 ft. lbs.).
(9) Install the drain plug and tighten to 34 N´m
(25 ft. lbs.) torque.
(10) Prime oil pump by squirting oil in the oil fil-
ter mounting hole and filling the J-trap of the front
timing cover. When oil is running out, install oil filter
that has been filled with oil.
(11) Lower the vehicle.
(12) Remove engine lifting fixture.
(13) On Manual Transmission vehicles, install the
shift lever.
(14) Connect the fuel lines (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE).
(15) Connect the heater hoses.
(16) Install the upper intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(17) Install the coil assemblies with the ignition
cables.
(18) Using a new gasket, install throttle body
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
THROTTLE BODY - INSTALLATION).
(19) Connect the throttle linkage.
(20) Install the air cleaner box.
9 - 362 ENGINE 8.0LDR
ENGINE 8.0L (Continued)

(21) Install the generator and wire connections
(Refer to 8 - ELECTRICAL/CHARGING/GENERA-
TOR - INSTALLATION).
(22) Install the upper crossmember.
(23) Install radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - INSTALLATION).
(24) Connect the lower radiator hose.
(25) Install the transmission oil cooler (Refer to 7 -
COOLING/TRANSMISSION/TRANS COOLER -
INSTALLATION).
(26) Connect the transmission cooler lines.
(27) Connect the power steering hoses, if equipped.
(28) Install the fan shroud.
(29) Install the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION).
(30) Connect the top radiator hose.
(31) Install the washer fluid reservoir bottle (Refer
to 8 - ELECTRICAL/WIPERS/WASHERS - INSTAL-
LATION).
(32) If equipped, install the condenser (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING/
A/C CONDENSER - INSTALLATION).
(33) Install the A/C compressor with the lines
attached (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/A/C COMPRESSOR -
INSTALLATION).
(34) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(35) Evacuate (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE) and charge the air conditioning system, if
equipped (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE).
(36) Add coolant to the cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(37) Install the battery.
(38) Warm engine and adjust as required.
(39) Road test vehicle.SPECIFICATIONS
TORQUE
TORQUE CHART 8.0L ENGINE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Camshaft SprocketÐBolt 75 55 Ð
Camshaft Thrust PlateÐ
Bolts22 16 Ð
Coil Pack BracketÐBolts 21 Ð 190
Connecting Rod CapÐBolts 61 45 Ð
Main BearingÐBolts
Step 1 27 20 Ð
Step 2 115 85 Ð
Crankshaft Pulley/DamperÐ
Bolt312 230 Ð
Crankshaft Rear Seal
RetainerÐ22 16 Ð
Bolts
Cylinder HeadÐBolts
Step 1 58 43 Ð
Step 2 143 105 Ð
Cylinder Head CoverÐBolts 16 Ð 144
Drive Plate to CrankshaftÐ
Bolts75 55 Ð
Drive Plate to Torque
ConverterÐ47 35 Ð
Bolts
EGR TubeÐNut 34 25 Ð
EGR ValveÐBolts 20 Ð 174
Engine Support Bracket/
InsulatorÐ68 50 Ð
Through Bolt
Engine Support Bracket/
Insulator to47 35 Ð
BlockÐBolts
Exhaust Manifold to Cylinder
HeadÐ22 16 Ð
Bolt
Generator MountingÐBolt 41 30 Ð
Generator to Intake Manifold
Bracket41 30 Ð
ÐBolts
DRENGINE 8.0L 9 - 363
ENGINE 8.0L (Continued)

AIR CLEANER ELEMENT
REMOVAL
Filter Element Only
Housing removal is not necessary for element (fil-
ter) replacement.
(1) Loosen clamp (Fig. 4) and disconnect air duct
at air cleaner cover.
(2) Pry over 4 spring clips (Fig. 4) from housing
cover (spring clips retain cover to housing).
(3) Release housing cover from locating tabs on
housing (Fig. 4) and remove cover.
(4) Remove air cleaner element (filter) from hous-
ing.
(5) Clean inside of housing before replacing ele-
ment.
Housing Assembly
(1) Loosen clamp (Fig. 4) and disconnect air duct
at air cleaner cover.
(2) Lift entire housing assembly from 4 locating
pins (Fig. 5).
INSTALLATION
(1) Install filter element into housing.
(2) Position housing cover into housing locating
tabs (Fig. 4).(3) Pry up 4 spring clips (Fig. 4) and lock cover to
housing.
(4) Install air duct to air cleaner cover and tighten
hose clamp to 3 N´m (30 in. lbs.) torque.
(5) If any other hose clamps were removed from
air intake system, tighten them to 3.4 N´m (30 in.
lbs.) torque.
(6) If any bolts were removed from air resonator
housing or air intake tubing, tighten them to 4.5 N´m
(40 in. lbs.) torque.
CYLINDER HEAD
DESCRIPTION
The alloy cast iron cylinder heads (Fig. 6) are held
in place by 12 bolts. The spark plugs are located in
the peak of the wedge between the valves.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET FAILURE
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
²Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
þ Loss of engine power
þ Engine misfiring
þ Poor fuel economy
Fig. 4 AIR CLEANER HOUSING COVER
1 - CLAMP
2 - AIR DUCT
3 - AIR CLEANER COVER
4 - LOCATING TABS
5 - CLIPS (4)
Fig. 5 AIR CLEANER HOUSING
1 - AIR CLEANER HOUSING ASSEMBLY
2 - LOCATING PINS (4)
9 - 370 ENGINE 8.0LDR

²Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
þ Engine overheating
þ Loss of coolant
þ Excessive steam (white smoke) emitting from
exhaust
þ Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test in this
section. An engine cylinder head gasket leaking
between adjacent cylinders will result in approxi-
mately a 50±70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove the heat shields (Fig. 7).
(4) Remove the intake manifold-to-generator
bracket support rod. Remove the generator (Refer to
8 - ELECTRICAL/CHARGING/GENERATOR -
REMOVAL).
(5) Remove closed crankcase ventilation system.
(6) Disconnect the evaporation control system.
(7) Remove the air cleaner.
(8) Perform the Fuel System Pressure release pro-
cedure (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY - STANDARD PROCEDURE). Disconnect the
Fig. 6 Cylinder Head Assembly
1 - SPARK PLUG
2 - INTAKE VALVES
3 - SPARK PLUG
4 - INTAKE VALVES
5 - SPARK PLUG
6 - SPARK PLUG
7 - INTAKE VALVE
8 - SPARK PLUG
9 - EXHAUST VALVE
10 - EXHAUST VALVES
11 - EXHAUST VALVES
Fig. 7 Spark Plug Wire Heat Shields (Left Side
Shown)
1 - EXHAUST MANIFOLD
2 - HEAT SHIELD
DRENGINE 8.0L 9 - 371
CYLINDER HEAD (Continued)

fuel line (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY/QUICK CONNECT FITTING - STANDARD
PROCEDURE).
(9) Disconnect accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(10) Remove coil pack and bracket (Fig. 8).
(11) Disconnect the coil wires.
(12) Disconnect heat indicator sending unit wire.
(13) Disconnect heater hoses and bypass hose.
(14) Remove upper intake manifold and throttle
body as an assembly (Refer to 9 - ENGINE/MANI-
FOLDS/INTAKE MANIFOLD - REMOVAL).
(15) Remove cylinder head covers and gaskets
(Refer to 9 - ENGINE/CYLINDER HEAD/CYLIN-
DER HEAD COVER(S) - REMOVAL).
(16) Remove the EGR tube. Discard the gasket, for
right side only.
(17) Remove lower intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL). Discard the flange side gaskets and the
front and rear cross-over gaskets.
(18) Disconnect exhaust pipe from exhaust mani-
fold.
(19) Remove exhaust manifolds and gaskets (Refer
to 9 - ENGINE/MANIFOLDS/EXHAUST MANIFOLD
- REMOVAL).
(20) Remove rocker arm assemblies and push rods
(Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER
ARM / ADJUSTER ASSY - REMOVAL). Identify to
ensure installation in original locations.(21) Remove the head bolts from each cylinder
head and remove cylinder heads. Discard the cylin-
der head gasket.
(22) Remove spark plugs.
CLEANING
Clean all surfaces of cylinder block and cylinder
heads. Be sure material does not fall into the lifters
and surrounding valley.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
Clean the exhaust manifold to cylinder head mat-
ing areas.
INSPECTION
Inspect all surfaces with a straightedge if there is
any reason to suspect leakage. The out-of-flatness
specifications are 0.0007 mm/mm (0.0004 inch/inch),
0.127 mm/152 mm (0.005 inch/6 inches) any direction
or 0.254 mm (0.010 inch) overall across head. If
exceeded, either replace head or lightly machine the
head surface.
The cylinder head surface finish should be
1.78-4.57 microns (15-80 microinches).
Inspect push rods. Replace worn or bent rods.
Inspect rocker arms. Replace if worn or scored.
INSTALLATION
(1) Position the new cylinder head gaskets onto
the cylinder block.
(2) Position the cylinder heads onto head gaskets
and cylinder block.
(3) Tighten the cylinder head bolts in two steps
(Fig. 9):
²Step 1ÐTighten all cylinder head bolts, in
sequence, to 58 N´m (43 ft. lbs.) torque.
²Step 2ÐTighten all cylinder head bolts, in
sequence, to 143 N´m (105 ft. lbs.) torque.
²
CAUTION: When tightening the rocker arm bolts,
make sure the piston in that cylinder is NOT at
TDC. Contact between the valves and piston could
occur.
Fig. 8 Coil Pack and Bracket
1 - COIL PACKS AND BRACKET
2 - MOUNTING BOLTS (4)
Fig. 9 Cylinder Head Bolt Tightening Sequence
9 - 372 ENGINE 8.0LDR
CYLINDER HEAD (Continued)

(4) Install push rods and rocker arm assemblies in
their original position (Refer to 9 - ENGINE/CYLIN-
DER HEAD/ROCKER ARM / ADJUSTER ASSY -
INSTALLATION).
(5) Install lower intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(6) Install the upper intake manifold onto the
lower intake manifold (Refer to 9 - ENGINE/MANI-
FOLDS/INTAKE MANIFOLD - INSTALLATION).
(7) Install the exhaust manifolds and new gaskets
(Refer to 9 - ENGINE/MANIFOLDS/EXHAUST
MANIFOLD - INSTALLATION).
(8) Install exhaust pipe to the exhaust manifold.
Tighten the bolts to 34 n´m (25 ft. lbs.) torque.
(9) Using a new gasket, position the EGR tube to
the intake manifold and the exhaust manifold.
Tighten the EGR tube nut to 34 N´m (25 ft. lbs.)
torque. Tighten the bolts to 20 N´m (174 in. lbs.)
torque.
(10) Install the heat shields and the washers.
Make sure that heat shields tabs hook over the
exhaust gasket.Tighten the nuts to 15 N´m (132 in.
lbs.) torque.
(11) Adjust and Install the spark plugs (Refer to 8
- ELECTRICAL/IGNITION CONTROL/SPARK
PLUG - INSTALLATION).
(12) Install coil packs and bracket. Tighten the
bracket bolts to 21 N´m (190 in. lbs.) torque. Connect
the coil wires.
(13) Connect heat indicator sending unit wire.
(14) Connect the heater hoses and bypass hose.
(15) Connect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(16) Install the fuel line (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE).
(17) Install the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - INSTALLATION)
and drive belt (Refer to 7 - COOLING/ACCESSORY
DRIVE/DRIVE BELTS - INSTALLATION).
(18) Install the intake manifold-to-generator
bracket support rod. Tighten the bolts to 41 N´m (30
ft. lbs.) torque.
(19) The cylinder head cover gasket can be used
again. Install the gasket onto the head rail.For the
left side the number tab is at the front of
engine with the number up. For the right side
the number tab is at the rear of engine with the
number up.
CAUTION: The cylinder head cover fasteners have a
special plating. DO NOT use alternative fasteners.(20) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(21) Install closed crankcase ventilation system.
(22) Connect the evaporation control system.
(23) Install the air cleaner.
(24) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(25) Connect the negative cable to the battery.
(26) Check for leaks (fuel, oil, antifreeze, etc.).
CYLINDER HEAD COVER(S)
DESCRIPTION
Die-cast magnesium cylinder head covers (Fig. 10)
reduce noise and provide a good sealing surface. A
steel backed silicon gasket is used with the cylinder
head cover. This gasket can be used again.
REMOVAL
Die-cast magnesium cylinder head covers (Fig. 12)
reduce noise and provide a good sealing surface. A
steel backed silicon gasket is used with the cylinder
head cover (Fig. 11).
(1) Disconnect the negative cable from the battery.
(2) Disconnect closed ventilation system and evap-
oration control system from cylinder head cover.
Identify each system for installation.
(3) Remove the upper intake manifold to remove
the right side head cover (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - REMOVAL).
Fig. 10 Cylinder Head Cover
1 - CYLINDER HEAD COVER
DRENGINE 8.0L 9 - 373
CYLINDER HEAD (Continued)

(4) Remove cylinder head cover bolts and stud
bolts. Remove the covers and gaskets (Fig. 11). The
gasket may be used again.
CLEANING
Clean cylinder head cover gasket surface.
Clean head rail, if necessary.
INSPECTION
Inspect cover for distortion and straighten, if nec-
essary.
Check the gasket for use in head cover installation.
If damaged, use a new gasket.
INSTALLATION
(1) Check the gasket for use in head cover instal-
lation. If damaged, use a new gasket.
(2) Install the gasket onto the head rail.For the
left side the number tab is at the front of
engine with the number up. For the right side
the number tab is at the rear of engine with the
number up.
CAUTION: The cylinder head cover fasteners have a
special plating. DO NOT use alternative fasteners.
(3) Position the cylinder head cover onto the gas-
ket. Install the stud bolts and hex head bolts in theproper positions (Fig. 12). Tighten the stud bolts and
the bolts to 16 N´m (144 in. lbs.) torque.
(4) If removed, install the upper intake manifold
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANI-
FOLD - INSTALLATION).
(5) Install closed crankcase ventilation system and
evaporation control system onto the proper head
cover. DO NOT switch the systems.
(6) Connect the negative cable to the battery.
(7) Start engine and check for leaks.
Fig. 11 Cylinder Head Cover Gaskets
1 - CYLINDER HEAD COVER GASKETS
2 - TAB WITH NUMBER UP
Fig. 12 Cylinder Head Covers
1 - CYLINDER HEAD COVER
2 - CYLINDER HEAD COVER GASKET
9 - 374 ENGINE 8.0LDR
CYLINDER HEAD COVER(S) (Continued)

(8) The cylinder head cover gasket can be used
again. Install the gasket onto the head rail.For the
left side the number tab is at the front of
engine with the number up. For the right side
the number tab is at the rear of engine with the
number up.
CAUTION: The cylinder head cover fasteners have a
special plating. DO NOT use alternative fasteners.
(9) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION) (Fig. 24).
(10) Install closed crankcase ventilation system.
(11) Connect the evaporation control system.
(12) Install air cleaner.
(13) Connect the negative cable to the battery.
(14) Road test vehicle and check for leaks.
INSTALLATIONÐVALVES AND VALVE SPRINGS
(1) Clean valves thoroughly. Discard burned,
warped and cracked valves.(2) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
(3) Measure valve stems for wear. If wear exceeds
0.051 mm (0.002 inch), replace the valve.
(4) Make sure there are no burrs on valve stems.
(5) Coat valve stems with lubrication oil. Insert
valves into valve guides in cylinder head.
(6) Install new seals on all valve guides(BLACK
on intake and BROWN on exhaust). Install valve
springs and valve retainers.
(7) Compress valve springs with Valve Spring
Compressor Tool MD-998772A and adapter 6716A,
install locks and release tool. Tap the retainer with a
brass or heavy plastic hammer to ensure locks have
been seated.
(8) If valves and/or seats were ground, measure
the installed height of springs. Make sure the mea-
surement is taken from bottom of spring seat in cyl-
inder head to the bottom surface of spring retainer. If
spacers are installed, measure from the top of spacer.
If height is greater than 42.86 mm (1-11/16 inches),
install a 1.587 mm (1/16 inch) spacer in head coun-
terbore. Ensure this brings spring height back to nor-
mal, 41.27 to 42.86 mm (1-5/8 to 1-11/16 inch).
(9) Install the cylinder head (Refer to 9 - ENGINE/
CYLINDER HEAD - INSTALLATION).
ROCKER ARM / ADJUSTER
ASSY
REMOVAL
(1) Disconnect spark plug wires by pulling the boot
straight out in line with plug.
(2) Remove cylinder head cover and gasket (Refer
to 9 - ENGINE/CYLINDER HEAD/CYLINDER
HEAD COVER(S) - REMOVAL).
(3) Remove the rocker arm bolts and the rocker
arm assembly (Fig. 25). Place rocker arm assemblies
on a bench in the same order as removed.
(4) Remove the push rods and place them on a
bench in the same order as removed.
INSTALLATION
CAUTION: DO NOT rotate or crank the engine dur-
ing or immediately after rocker arm installation.
Allow the hydraulic roller tappets adequate time to
bleed down (about 5 minutes).
Fig. 24 Cylinder Head Covers
1 - CYLINDER HEAD COVER
2 - CYLINDER HEAD COVER GASKET
DRENGINE 8.0L 9 - 379
INTAKE/EXHAUST VALVES & SEATS (Continued)