1998 DODGE RAM 1500 Ignition cylinder

INSTALLATION
(1) Position the oil pump onto the crankshaft and
install one oil pump retaining bolts.
(2) Position the primary timing chain tensioner
and install three retaining bolts.
(3) Tighten the oil pump and primary timing chain
tensioner retaining bolts to 28 N´m (250 in. lbs.) in
the sequence shown (Fig. 107).
(4) Install the secondary timing chain tensioners
and timing chains (Refer to 9 - ENGINE/VALVE
TIMING/TIMING BELT/CHAIN AND SPROCKETS -
INSTALLATION).
(5) Install the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(6) Install the pick-up tube and oil pan (Refer to 9
- ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
INTAKE MANIFOLD
DESCRIPTION
The intake manifold is made of a composite mate-
rial and features long runners which maximizes low
end torque. The intake manifold uses single plane
sealing which consist of eight individual press in
place port gaskets to prevent leaks. Eight studs and
two bolts are used to fasten the intake to the head.
DIAGNOSIS AND TESTINGÐINTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.
(3) If a change in RPM is observed the area of the
suspected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove resonator assembly and air inlet hose.
(3) Disconnect throttle and speed control cables.
(4) Disconnect electrical connectors for the follow-
ing components:
²Manifold Absolute Pressure (MAP) Sensor
²Intake Air Temperature (IAT) Sensor
²Throttle Position (TPS) Sensor
²Coolant Temperature (CTS) Sensor
²Idle Air Control (IAC) Motor
(5) Disconnect brake booster hose and positive
crankcase ventilation (PCV) hose.
(6) Disconnect generator electrical connections.
(7) Disconnect air conditioning compressor electri-
cal connections.
(8) Disconnect left and right radio suppressor
straps.
(9) Disconnect and remove ignition coil towers
(Refer to 8 - ELECTRICAL/IGNITION CONTROL/
IGNITION COIL - REMOVAL).
(10) Remove top oil dipstick tube retaining bolt
and ground strap.
(11) Bleed fuel system (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY - STANDARD PROCE-
DURE).
(12) Remove fuel rail (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/FUEL RAIL - REMOVAL).
(13) Remove throttle body assembly and mounting
bracket.
(14) Drain cooling system below coolant tempera-
ture level (Refer to 7 - COOLING - STANDARD
PROCEDURE).
(15) Remove the heater hoses from the engine
front cover and the heater core.
Fig. 107 Oil Pump And Primary Timing Chain
Tensioner Tightening Sequence
DRENGINE - 4.7L 9 - 159
OIL PUMP (Continued)

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either per-
formance (e.g., engine idles rough and stalls) or
mechanical (e.g., a strange noise).
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING) - PERFORMANCE and (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)ÐMECHANICAL for
possible causes and corrections of malfunctions.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
DIAGNOSIS AND TESTING) and (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION - DIAGNOSIS
AND TESTING) for the fuel system diagnosis.Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following diagnosis:
²Cylinder Compression Pressure Test (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).
²Cylinder Combustion Pressure Leakage Test
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING).
²Engine Cylinder Head Gasket Failure Diagnosis
(Refer to 9 - ENGINE/CYLINDER HEAD - DIAGNO-
SIS AND TESTING).
²Intake Manifold Leakage Diagnosis (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
DIAGNOSIS AND TESTING).
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
6. Dirt or water in fuel system. 6. Clean system and replace fuel
filter.
7. Faulty fuel pump, relay or wiring. 7. Repair or replace as necessary.
DRENGINE - 5.7L 9 - 183
ENGINE - 5.7L (Continued)

CONDITION POSSIBLE CAUSE CORRECTION
ENGINE STALLS OR ROUGH IDLE 1. Idle speed set to low. 1. (Refer to 14 - FUEL SYSTEM/
FUEL INJECTION/IDLE AIR
CONTROL MOTOR - REMOVAL).
2. Idle mixture too lean or too rich. 2. Refer to Powertrain Diagnosis
Information.
3. Vacuum leak. 3. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
5. Incorrect engine timing. 5. (Refer to 9 - ENGINE/VALVE
TIMING - STANDARD PROCEDURE).
1. ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped spark
plugs.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
2. Dirt or water in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/FUEL PUMP -
DIAGNOSIS AND TESTING).
4. Blown cylinder head gasket. 4. Replace cylinder head gasket.
5. Low compression. 5. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
6. Burned, warped or pitted valves. 6. Replace as necessary.
7. Plugged or restricted exhaust
system.7. Inspect and replace as necessary.
8. Faulty coil. 8. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
1. ENGINE MISSES ON
ACCELERATION1. Spark plugs dirty or incorrectly
gapped.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
2. Dirt in fuel system. 2. Clean fuel system.
3. Burned, warped or pitted valves. 3. Replcae as necessary.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
1. ENGINE MISSES AT HIGH SPEED 1. Spark plugs dirty or incorrectly
gapped.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
2. Faulty coil. 2. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
3. Dirt or water in fuel system. 3. Clean system and replace fuel
filter.
9 - 184 ENGINE - 5.7LDR
ENGINE - 5.7L (Continued)

DIAGNOSIS AND TESTING - CYLINDER
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.
(3) Disable the fuel system (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DESCRIPTION).
(4) Remove the ASD relay (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/AUTO SHUT DOWN
RELAY - REMOVAL).
(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 3rd
revolution. Continue the test for the remaining cylin-
ders.
(7) (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
jacket.
²Any causes for combustion/compression pressure
loss.
(1) Check the coolant level and fill as required. DO
NOT install the radiator cap.
(2) Start and operate the engine until it attains
normal operating temperature, then turn the engine
OFF.
(3) Remove the spark plugs.
(4) Remove the oil filler cap.
(5) Remove the air cleaner hose.
(6) Calibrate the tester according to the manufac-
turer'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.
(7) Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
Set piston of cylinder to be tested at TDC compres-
sion,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 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. Inspect
valve springs. Replace as necessary.
AIR ESCAPES THROUGH TAILPIPE Exhaust valve bent, burnt, or not
seated properlyInspect valve and valve seat. Reface
or replace, as necessary. Inspect
valve springs. 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
9 - 186 ENGINE - 5.7LDR
ENGINE - 5.7L (Continued)

AIR INTAKE SYSTEM
REMOVAL
Filter Element Only
Housing removal is not necessary for element (fil-
ter) replacement.
(1) Loosen clamp (Fig. 2) and disconnect air duct
at air cleaner cover.
(2) Pry over 4 spring clips (Fig. 2) from housing
cover (spring clips retain cover to housing).
(3) Release housing cover from locating tabs on
housing (Fig. 2) 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. 2) and disconnect air duct
at air cleaner cover.
(2) Lift entire housing assembly from 4 locating
pins (Fig. 3).
INSTALLATION
(1) Install filter element into housing.
(2) Position housing cover into housing locating
tabs (Fig. 2).(3) Pry up 4 spring clips (Fig. 2) 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
OPERATIONÐCYLINDER HEAD
The cylinder head closes the combustion chamber
allowing the pistons to compress the air fuel mixture
to the correct ratio for ignition. The valves located in
the cylinder head open and close to either allow clean
air into the combustion chamber or to allow the
exhaust gases out, depending on the stroke of the
engine.
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:
Fig. 2 AIR CLEANER HOUSING COVER
1 - CLAMP
2 - AIR DUCT
3 - AIR CLEANER COVER
4 - LOCATING TABS
5 - CLIPS (4)
Fig. 3 AIR CLEANER HOUSING
1 - AIR CLEANER HOUSING ASSEMBLY
2 - LOCATING PINS (4)
DRENGINE - 5.7L 9 - 199

CAUTION: The head gaskets are marked ªTOPº to
indicate which side goes up.
(4) Position cylinder heads onto head gaskets and
cylinder block.
(5) Tighten the cylinder head bolts in three steps
(Fig. 4):
²Step 1Ð Snug tighten M12 cylinder head bolts,
in sequence, to 34 N´m (25 ft. lbs.) and M8 bolts to
20 N´m (15 ft. lbs.) torque.
²Step 2Ð Tighten M12 cylinder head bolts, in
sequence, to 54 N´m (40 ft. lbs.) and verify M8 bolts
to 20 N´m (15 ft. lbs.) torque..
²Step 3Ð Turn M12 cylinder head bolts, in
sequence, 90 degrees and tighten M8 bolts to 34 N´m
(25 ft. lbs.) torque.
(6) Install push rods and rocker arm assemblies in
their original position.
(7) Install the intake manifold and throttle body
assembly.
(8) If required, adjust spark plugs to specifications.
Install the plugs.
(9) Connect the heater hoses.
(10) Install the fuel supply line.
(11) Install the generator and drive belt.
(12) Install cylinder head covers(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(13) Connect the evaporation control system.
(14) Install the air cleaner.
(15) Fill cooling system.
(16) Connect the negative cable to the battery.
(17) Start engine check for leaks.CYLINDER HEAD COVER(S)
REMOVAL
(1) Disconnect battery negative cable.
(2) Disconnect coil on plug connectors.
CAUTION: The ground straps must be installed in
the same location as removed. The covers are
machined to accept the ground straps in those
locations only.
(3) Remove cylinder head cover retaining bolts,
and ground straps.
(4) Remove cylinder head cover.
NOTE: The gasket may be used again, provided no
cuts, tears, or deformation has occurred.
INSTALLATION
CAUTION: Do not use harsh cleaners to clean the
cylinder head covers. Severe damage to covers
may occur.
CAUTION: DO NOT allow other components includ-
ing the wire harness to rest on or against the
engine cylinder head cover. Prolonged contact with
other objects may wear a hole in the cylinder head
cover.
(1) Clean cylinder head cover and both sealing sur-
faces. Inspect and replace gasket as necessary.
(2)
Install cylinder head cover and hand start all fas-
teners. Verify that all double ended studs are in the cor-
rect location and install left and right ground straps.
CAUTION: The ground straps must be installed in
the same location as removed. The covers are
machined to accept the ground straps in those
locations only.
NOTE: The right hand ground strap is located on
the front inboard stud. The left hand ground strap
is located on the rear inboard stud.
(3) Tighten cylinder head cover bolts and double
ended studs to 8 N´m (70 in. lbs). Begin torque
sequence in the middle of head cover and torque
bolts moving outward in a crisscross pattern from top
to bottom.
(4) Install ignition coil on plug, and torque fasten-
ers to 12 N´m (105 in. lbs)
(5) Connect, ignition coil electrical connectors.
(6) Install PCV hose.
(7) Connect battery negative cable.
Fig. 4 CYLINDER HEAD TIGHTENING SEQUENCE
DRENGINE - 5.7L 9 - 201
CYLINDER HEAD (Continued)

VALVE SPRINGS
REMOVAL
(1) Disconnect negative battery cable.
(2) Remove air cleaner assembly.
(3) Remove air intake resonator.
(4) Remove spark plug cables.
(5) Remove ignition coil connectors (Fig. 6).
(6) Remove ignition coils.
(7) Remove one spark plug.
(8) Remove valve cover.
CAUTION: The piston must be at TDC, and both
valves closed on the cylinder to be serviced.
NOTE: If removing intake valve spring, install spe-
cial tool# 9070, pushrod retaining plate, to retain
the intake pushrods.
(9) Remove exhaust/intake rocker arm shafts.
(10) Install spring compressor, special tool# 9065.
NOTE: All valve springs and seals are removed in
the same manner.(11) Charge cylinder with air.
NOTE: Tap the top of the valve spring retainer to
loosen the spring retainers locks.
(12) Compress valve spring and remove valve
retainer locks.
(13) Release spring compressor and remove valve
spring.
NOTE: The valve springs are interchangeable
between intake and exhaust.
(14) Remove valve seal.
INSTALLATION
(1) Install valve seal.
(2) Install valve spring.
(3) Using special tool# 9065, compress valve spring
and install valve spring retainer and locks.
(4) Release air charge in cylinder.
(5) Remove spring compressor tool # 9065.
CAUTION: Verify that the pushrods are fully seated
into lifter and rocker arm. Recheck after rocker arm
shaft has been torqued to specification.
(6) Install rocker arm shaft and pushrods(Refer to
9 - ENGINE/CYLINDER HEAD/ROCKER ARM /
ADJUSTER ASSY - INSTALLATION).
(7) Tighten the rocker shaft bolts to 22 N´m (195
in. lbs.) torque,using the following sequence:Center,
center-right, center-left, right, left.
(8) Remove special tool# 9070, pushrod retaining
plate, if used.
(9) Install cylinder head cover.
(10) Tighten cylinder head cover bolts and double
ended studs(Refer to 9 - ENGINE/CYLINDER
HEAD/CYLINDER HEAD COVER(S) - INSTALLA-
TION).
(11) Install spark plugs.
(12) Install ignition coil on plug, and torque fas-
teners to 12 N´m (105 in. lbs)
(13) Install ignition coil connectors.
(14) Install spark plug cables.
(15) Install air intake resonator.
(16) Install air cleaner assembly.
(17) Connect negative battery cable.
Fig. 6 IGNITION COIL R/I Ð 5.7L V-8
1 - SLIDE LOCK (SLIDE OUTWARD TO UNLOCK)
2 - SPARK PLUG CABLE (TO OPPOSITE CYLINDER BANK
SPARK PLUG)
3 - RELEASE LOCK / TAB (PUSH HERE)
4 - ELEC. CONNECTOR
5 - IGNITION COIL
6 - COIL MOUNTING BOLTS (2)
7 - SPARK PLUG CABLE (TO OPPOSITE CYLINDER BANK
IGNITION COIL)
9 - 204 ENGINE - 5.7LDR

REMOVAL
3.7L V-6
WARNING: THE FUEL SYSTEM IS UNDER CON-
STANT PRESSURE EVEN WITH ENGINE OFF.
BEFORE SERVICING FUEL RAIL, FUEL SYSTEM
PRESSURE MUST BE RELEASED.
CAUTION: The left and right fuel rails are replaced
as an assembly. Do not attempt to separate rail
halves at connector tubes (Fig. 18). Due to design
of tubes, it does not use any clamps. Never attempt
to install a clamping device of any kind to tubes.
When removing fuel rail assembly for any reason,
be careful not to bend or kink tubes.
(1) Remove fuel tank filler tube cap.
(2) Perform Fuel System Pressure Release Proce-
dure.
(3) Remove negative battery cable at battery.
(4) Remove air duct at throttle body air box.
(5) Remove air box at throttle body.
(6) Remove air resonator mounting bracket at
front of throttle body (2 bolts).
(7) Disconnect fuel line latch clip and fuel line at
fuel rail. A special tool will be necessary for fuel line
disconnection. Refer to Quick-Connect Fittings.
(8) Remove necessary vacuum lines at throttle
body.
(9) Disconnect electrical connectors at all 6 fuel
injectors. To remove connector refer to (Fig. 17). Push
red colored slider away from injector (1). While push-
ing slider, depress tab (2) and remove connector (3)
from injector. The factory fuel injection wiring har-
ness is numerically tagged (INJ 1, INJ 2, etc.) for
injector position identification. If harness is not
tagged, note wiring location before removal.
(10) Disconnect electrical connectors at all throttle
body sensors.
(11) Remove 6 ignition coils. Refer to Ignition Coil
Removal/Installation.
(12) Remove 4 fuel rail mounting bolts (Fig. 18).
(13) Gently rock and pullleftside of fuel rail until
fuel injectors just start to clear machined holes in
cylinder head. Gently rock and pullrightside of rail
until injectors just start to clear cylinder head holes.
Repeat this procedure (left/right) until all injectors
have cleared cylinder head holes.
(14) Remove fuel rail (with injectors attached)
from engine.
(15) If fuel injectors are to be removed, refer to
Fuel Injector Removal/Installation.
Fig. 17 REMOVE/INSTALL INJECTOR CONNECTOR
Fig. 18 FUEL RAIL REMOVE/INSTALL - 3.7L V-6
1 - MOUNTING BOLTS (4)
2 - QUICK-CONNECT FITTING
3 - FUEL RAIL
4 - INJ. #1
5 - INJ. #3
6 - INJ. #5
7 - INJ. #2
8 - INJ. #4
9 - INJ. #6
10 - CONNECTOR TUBE
DRFUEL DELIVERY - GAS 14 - 13
FUEL RAIL (Continued)