1998 DODGE RAM 1500 Exhaust

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTIONS
NOISY VALVES 1. High or low oil level in
crankcase.1. (Refer to LUBRICATION &
MAINTENANCE -
SPECIFICATIONS)
2. Thin or diluted oil. 2. Change oil and filter.
3. Low oil pressure. 3. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
4. Dirt in lash adjusters. 4. Replace as necessary.
5. Worn rocker arms. 5. Replace as necessary.
6. Worn lash adjusters 6. Replace as necessary.
7. Worn valve guides. 7. (Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE)
8. Excessive runout of valve seats
on valve faces.8. (Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE)
CONNECTING ROD NOISE 1. Insufficient oil supply. 1. (Refer to LUBRICATION &
MAINTENANCE -
SPECIFICATIONS)
2. Low oil pressure. 2. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Connecting rod journal
out-of-round.5. Service or replace crankshaft.
6. Misaligned connecting rods. 6. Replace bent connecting rods.
MAIN BEARING NOISE 1. Insufficient oil supply. 1. (Refer to LUBRICATION &
MAINTENANCE -
SPECIFICATIONS)
2. Low oil pressure. 2. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Excessive end play. 5. Check thrust washers for wear.
6. Crankshaft journal out-of round. 6. Service or replace crankshaft.
7. Loose flywheel or torque
converter.7. Tighten to correct torque
DRENGINE - 5.7L 9 - 185
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)

(6) Remove the viscous fan/drive (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(7) Remove radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(8) Remove the upper crossmember and top core
support.
NOTE: It is not necessary to drain A/C system for
engine removal.
(9) Remove the A/C compressor with the lines
attached. Secure compressor out of the way.
(10) Remove generator assembly (Refer to 8 -
ELECTRICAL/CHARGING/GENERATOR -
REMOVAL).
(11) Remove the intake manifold and IAFM as an
assembly(Refer to 9 - ENGINE/MANIFOLDS/IN-
TAKE MANIFOLD - REMOVAL).
(12) Disconnect the heater hoses.
NOTE: It is not necessary to disconnect P/S hoses
from pump, for P/S pump removal.
(13) Remove the power steering pump and set
aside.
(14) Disconnect the fuel supply line (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/QUICK CON-
NECT FITTING - STANDARD PROCEDURE).
(15) Raise and support the vehicle on a hoist and
drain the engine oil.
(16) Remove engine front mount thru-bolt nuts.
(17) Remove right side axle retaining bolts.
(18) Disconnect the transmission oil cooler lines
from their retainers at the oil pan bolts.
(19) Disconnect exhaust pipe at manifolds.
(20) Disconnect the starter wires. Remove starter
motor (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - REMOVAL).
(21) Remove the structural dust cover and trans-
mission inspection cover,(Refer to 9 - ENGINE/EN-
GINE BLOCK/STRUCTURAL COVER - REMOVAL).
(22) Remove drive plate to converter bolts (Auto-
matic transmission equipped vehicles).
(23) Remove transmission bell housing to engine
block bolts.
(24) Lower the vehicle.
(25) Install engine lift fixture, special tool # 8984.
(26) Separate engine from transmission, remove
engine from vehicle, and install engine assembly on a
repair stand.
INSTALLATION
(1) Install engine lift fixture Special tool # 8984.
(2) Position the engine in the engine compartment.
(3) Lower engine into compartment and align
engine with transmission:²Manual Transmission: Align clutch disc assem-
bly (if disturbed). Install transmission input shaft
into clutch disc while mating engine and transmis-
sion surfaces. Install two transmission to engine
block mounting bolts finger tight.
²Automatic Transmission: Mate engine and trans-
mission and install two transmission to engine block
mounting bolts finger tight.
(4) Position the thru-bolt into the support cushion
brackets.
(5) Lower engine assembly until engine mount
through bolts rest in mount perches.
(6) Install remaining transmission to engine block
mounting bolts and tighten.
(7) Tighten engine mount through bolts.
(8) Install drive plate to torque converter bolts.
(Automatic transmission models)
(9) Install the structural dust cover and transmis-
sion dust cover,(Refer to 9 - ENGINE/ENGINE
BLOCK/STRUCTURAL COVER - INSTALLATION).
(10) Install the starter and connect the starter
wires (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - INSTALLATION).
(11) Install exhaust pipe to manifold.
(12) Lower the vehicle.
(13) Remove engine lift fixture, special tool # 8984.
(14) Connect the fuel supply line (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/QUICK CON-
NECT FITTING - STANDARD PROCEDURE).
(15) Reinstall the power steering pump.
(16) Connect the heater hoses.
(17) Install the intake manifold.
(18) Using a new gasket, install throttle body
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
THROTTLE BODY - INSTALLATION).
(19) Install the generator and wire connections
(Refer to 8 - ELECTRICAL/CHARGING/GENERA-
TOR - INSTALLATION).
(20) Install a/c compressor and lines (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION).
(21) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(22) Install upper radiator support crossmember.
(23) Install radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - INSTALLATION).
(24) Connect the radiator lower hose.
(25) Connect the transmission oil cooler lines to
the radiator.
(26) Install the fan shroud.
(27) Install the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION).
(28) Connect the radiator upper hose.
(29) Install the washer bottle.
(30) Connect the transmission cooler lines.
DRENGINE - 5.7L 9 - 191
ENGINE - 5.7L (Continued)

VALVE TIMING
DESCRIPTION SPECIFICATION
Intake
Opens (BTDC) 7.0É
Closes (ATDC) 253.0É
Exhaust
Opens (BTDC) 233É
Closes (ATDC) 27É
Duration 253.70É
Valve Overlap 34É
CYLINDER HEAD
DESCRIPTION SPECIFICATION
Valve Seat Angle 44.5É - 45.0É
Valve Seat Runout (MAX) 0.05 mm (0.0019 in.)
Valve Seat Width (Finish)
Intake 1.018 - 1.62 mm
(0.0464 - 0.0637 in.)
Exhaust 1.48 - 1.92 mm
(0.0582 - 0.0755 in.)
Guide Bore Diameter
(Std.)7.975 - 8.00 mm
(0.313 - 0.314 in.)
HYDRAULIC TAPPETS
DESCRIPTION SPECIFICATION
Metric Standard
Body Diameter 21.387 - 21.405
mm0.8420 - 0.8427
in.
Clearance (To
Bore)0.020 - 0.063
mm0.0007 - 0.0024
in.
Dry Lash 3.0 mm (at the
valve)0.1181 in.
VALVES
DESCRIPTION SPECIFICATION
Face Angle 45.0É - 45.5É
Head Diameter
Intake 50.67 - 50.93 mm
(1.99 - 2.00 in.)
Exhaust 39.27 - 39.53 mm
(1.54 - 1.55 in.)
Length (Overall)
Intake 123.38 - 123.76 mm
(4.857 - 4.872 in.)
Exhaust 120.475 - 120.855 mm
(4.743 - 4.758 in.)
Stem Diameter
Intake 7.935 - 7.953 mm
(0.312 - 0.313 in.)
Exhaust 7.905 - 7.925 mm
(0.311 - 0.312 in.)
Stem - to - Guide
Clearance
Intake 0.022 - 0.065 mm
(0.0008 - 0.0025 in.)
Exhaust 0.050 - 0.095 mm
(0.0019 - 0.0037 in.)
Valve Lift ( @ Zero Lash)
Intake 12.0 mm (0.472 in.)
Exhaust 11.70 mm (0.460 in.)
9 - 194 ENGINE - 5.7LDR
ENGINE - 5.7L (Continued)

VALVE SPRING
DESCRIPTION SPECIFICATION
Spring Force (Valve
Closed)
Intake and Exhaust 422.0 N @ 46.0 mm
(95lbs. @ 1.81 in.)
Spring Force (Valve
Open)
Intake and Exhaust @ 33.5 mm
Number of Coils
Intake and Exhaust 7.4
Wire Diameter
Intake and Exhaust 5.39 ý 4.52 mm
(0.212 - 0.177 in.)
Installed Height (Spring
Seat to Bottom of
Retainer)
Intake and Exhaust 46.0 mm (1.81 in.)
OIL PUMP
DESCRIPTION SPECIFICATION
Clearance Over Rotors
(MAX)0.095 mm (0.0038 in.)
Outer Rotor to Pump
Body Clearance (MAX).235 mm (.009 in.)
Tip Clearance Between
Rotors (MAX)0.150 mm (0.006 in.)
OIL PRESSURE
SPECIFICATION SPECIFICATION
At Curb Idle Speed
(MIN)*25 kPa (4 psi)
@ 3000 rpm 170 - 758 kPa (25 - 110
psi)
* CAUTION: If pressure is zero at curb idle, DO
NOT run engine
TORQUE
TORQUE CHART 5.7L ENGINE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Block Pipe Plugs
(1/4 NPT)20 Ð 177
(3/8 NPT) 27 Ð 240
Camshaft SprocketÐBolt 122 90 Ð
Camshaft Tensioner
PlateÐBolts28 Ð 250
Timing Chain Case CoverÐ
Bolts28 Ð 250
Lifting Stud 55 40 Ð
Connecting Rod CapÐBolts 21
plus
90É
Turn15
plus
90É
TurnÐ
Main Bearing CapÐBolts
M-1227
plus
90É
TurnÐÐ
Crossbolts
M-828 Ð Ð
Cylinder HeadÐBolts
M-12 Bolts
Step 1 34 25 Ð
Step 2 54 40 Ð
Step 3 Turn
90ÉTurn
90ÉÐ
M-8 Bolts Ð
Step 1 20 15 Ð
Step 2 34 25 Ð
Cylinder Head CoverÐBolts 8 Ð 70
Exhaust Manifold to Cylinder
Head25 Ð 220
Flexplate to crankshaftÐBolts 95 70 Ð
Flywheel to crankshaftÐBolts 75 55 Ð
Front InsulatorÐThrough
bolt/nut95 70 Ð
Front Insulator to Support
Bracket
ÐStud Nut (4WD) 41 30 Ð
ÐThrough Bolt/Nut (4WD) 102 75 Ð
Front Insulator to BlockÐ
Bolts (2WD)95 70 Ð
DRENGINE - 5.7L 9 - 195
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

þ Loss of engine power
þ Engine misfiring
þ Poor fuel economy
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 battery negative cable.
(2) Drain cooling system.
(3) Remove the air cleaner resonator and duct
work.
(4) Remove the generator.
(5) Remove closed crankcase ventilation system.
(6) Disconnect the evaporation control system.
(7) Perform the Fuel System Pressure Release pro-
cedure (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY - STANDARD PROCEDURE). Disconnect the
fuel supply line (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/QUICK CONNECT FITTING - STAN-
DARD PROCEDURE).
(8) Disconnect heater hoses.
(9) Remove cylinder head covers and gaskets.
(10) Remove intake manifold and throttle body as
an assembly.
(11) Remove rocker arm assemblies and push rods.
Identify to ensure installation in original locations.
(12) Remove the head bolts from each cylinder
head and remove cylinder heads. Discard the cylin-
der head gasket.
CLEANING
Clean all surfaces of cylinder block and cylinder
heads.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
INSPECTION
(1) Inspect the cylinder head for out-of-flatness,
using a straightedge and a feeler gauge. If tolerances
exceed 0.0508 mm (0.002 in.) replace the cylinder
head.
(2) Inspect the valve seats for damage. Service the
valve seats as necessary.
(3) Inspect the valve guides for wear, cracks or
looseness. If either condition exist, replace the cylin-
der head.
(4) Inspect pushrods. Replace worn or bent push-
rods.
INSTALLATION
(1) Clean all surfaces of cylinder block and cylin-
der heads.
(2) Clean cylinder block front and rear gasket sur-
faces using a suitable solvent.
CAUTION: The head gaskets are not interchange-
able between left and right sides. They are marked
ªLº and ªRº to indicate left and right sides.
(3) Position new cylinder head gaskets onto the
cylinder block.
9 - 200 ENGINE - 5.7LDR
CYLINDER HEAD (Continued)

INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
DESCRIPTION - VALVE GUIDES
The valve guides are made of powered metal and
are pressed into the cylinder head. The guides are
not replaceable or serviceable, and valve guide ream-
ing is not recommended. If the guides are worn
beyond acceptable limits, replace the cylinder heads.
DESCRIPTION
Both the intake and exhaust valves are made of
steel. The intake valve is 50.93 mm (2.00 inches) in
diameter and the exhaust valve is 39.53 mm (1.55
inches) in diameter. All valves use three bead lock
keepers to retain the springs and promote valve rota-
tion.
STANDARD PROCEDURE - REFACING
NOTE: Valve seats that are worn or burned can be
reworked, provided that correct angle and seat
width are maintained. Otherwise the cylinder head
must be replaced.
NOTE: When refacing valves and valve seats, it is
important that the correct size valve guide pilot be
used for reseating stones. A true and complete sur-
face must be obtained.
(1) Using a suitable dial indicator measure the
center of the valve seat Total run out must not
exceed 0.051 mm (0.002 in).
(2) Apply a small amount of Prussian blue to the
valve seat, insert the valve into the cylinder head,
while applying light pressure on the valve rotate the
valve. Remove the valve and examine the valve face.
If the blue is transferred below the top edge of the
valve face, lower the valve seat using a 15 degree
stone. If the blue is transferred to the bottom edge of
the valve face, raise the valve seat using a 65 degree
stone.
(3) When the seat is properly positioned the width
of the intake seat must be 1.018 - 1.62 mm (0.0464 -
0.0637 in.) and the exhaust seat must be 1.48 - 1.92
mm (0.058 - 0.075 in.).
(4) Check the valve spring installed height after
refacing the valve and seat. The installed height for
both intake and exhaust valve springs must not
exceed 46.0 mm (1.81 in.).
VALVE FACE AND VALVE SEAT ANGLE CHART
DESCRIPTION SPECIFICATION
SEAT WIDTH
INTAKE 1.018 - 1.62 mm
(0.0464 - 0.0637 in.)
EXHAUST 1.48 - 1.92 mm
(0.058 - 0.075 in.)
FACE ANGLE
(INT. AND EXT.) 45É - 45
1¤2É
SEAT ANGLE
(INT. AND EXT.) 44
1¤2É - 45É
(5)
The valve seat must maintain an angle of 44.5 ±
45.0 degrees angle.
(6) The valve face must maintain a face angle of
45.0 ± 45.5 degrees angle (Fig. 5).
Fig. 5 Valve Assembly Configuration
1 - VALVE LOCKS (3±BEAD)
2 - RETAINER
3 - VALVE STEM OIL SEAL
4 - INTAKE VALVE
5 - EXHAUST VALVE
6 - VALVE SPRING
9 - 202 ENGINE - 5.7LDR