1998 DODGE RAM 1500 Exhaust manifold

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - GAS ENGINE
EXHAUST SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
EXCESSIVE EXHAUST NOISE OR
LEAKING EXHAUST GASES1. Leaks at pipe joints. 1. Tighten clamps/bolts at leaking
joints.
2. Rusted or blown out muffler. 2. Replace muffler. Inspect exhaust
system.
3. Broken or rusted out exhaust
pipe.3. Replace exhaust pipe.
4. Exhaust pipe leaking at manifold
flange.4. Tighten/replace flange attaching
nuts/bolts.
5. Exhaust manifold cracked or
broken.5. Replace exhaust manifold.
6. Leak between exhaust manifold
and cylinder head.6. Tighten exhaust manifold to
cylinder head bolts.
7. Catalytic converter rusted or
blown out.7. Replace catalytic converter assy.
8. Restriction in exhaust system. 8. Remove restriction, if possible.
Replace restricted part if necessary.
CAUTION:
When servicing and replacing exhaust system components, disconnect the oxygen sensor connector(s). Allowing
the exhaust to hang by the oxygen sensor wires will damage the harness and/or sensor.
11 - 4 EXHAUST SYSTEMDR
EXHAUST SYSTEM (Continued)

DIAGNOSIS AND TESTING - DIESEL ENGINE
EXHAUST SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
EXCESSIVE EXHAUST NOISE OR
LEAKING EXHAUST GASES1. Leaks at pipe joints. 1. Tighten clamps/bolts at leaking
joints.
2. Rusted or blown out muffler. 2. Replace muffler. Inspect exhaust
system.
3. Broken or rusted out exhaust
pipe.3. Replace exhaust pipe.
4. Exhaust pipe leaking at manifold
flange.4. Tighten/replace flange attaching
nuts/bolts.
5. Exhaust manifold cracked or
broken.5. Replace exhaust manifold.
6. Leak between exhaust manifold
and cylinder head.6. Tighten exhaust manifold to
cylinder head bolts. Replace gasket
if necessary.
7. Turbocharger mounting flange
cracked.7. Remove turbocharger and
inspect. (Refer to 11 - EXHAUST
SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER -
REMOVAL).
8. Restriction in exhaust system. 8. Remove restriction, if possible.
Replace restricted part if necessary.
SPECIFICATIONS - TORQUE
DESCRIPTION N´m Ft.
Lbs.In.
Lbs.
Bolt-Adjusting Strap 23 - 200
Nuts-Air Heater Power
Supply14 - 124
Bolts-Air Inlet Housing 24 18 -
Nuts-Cab Heater Supply/
Return Line24 18 -
Nuts-Exhaust Clamp 54.3 40 -
Bolts-Exhaust Manifold to
Cylinder Head-(Diesel
Engine)43 32 -
Bolts-Exhaust Manifold to
Cylinder Head-(5.9L)31 23 -
Bolts-Exhaust Manifold to
Cylinder Head-(8.0L)22 - 195
Bolts-Exhaust Pipe to
Manifold31 23 -
Bolts-Generator Mounting 41 30 -
DESCRIPTION N´m Ft.
Lbs.In.
Lbs.
Bolts-Charge Air Cooler
Mounting2-17
Nuts-Charge Air Cooler Duct 11 - 95
Bolt-Generator to Block-
Diesel24 18 -
Nuts and Bolts-Heat Shield 11 - 95
Turbocharger flange studs 24 18 -
Nuts-Turbocharger Mounting 43 32 -
Bolts-Turbocharger Oil Drain
Tube24 18 -
Fitting-Turbocharger Oil
Supply Line24 18 -
Nut-Turbocharger V-Band
Clamp5.6 - 70
Turbocharger Oil Supply
fitting (at Turbocharger)36 27 -
Turbocharger Oil Supply
fitting (at lube filter head)24 18 -
Turbocharger Drain Hose
Clamps8-71
DREXHAUST SYSTEM 11 - 5
EXHAUST SYSTEM (Continued)

SPECIAL TOOLS
CATALYTIC CONVERTER
DESCRIPTION - CATALYTIC CONVERTER
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
CAUTION: DO NOT remove spark plug wires from
plugs or by any other means short out cylinders.
Failure of the catalytic converter can occur due to a
temperature increase caused by unburned fuel
passing through the converter.
The stainless steel catalytic converter body is
designed to last the life of the vehicle. Excessive heat
can result in bulging or other distortion, but exces-
sive heat will not be the fault of the converter. If
unburned fuel enters the converter, overheating may
occur. If a converter is heat-damaged, correct the
cause of the damage at the same time the converter
is replaced. Also, inspect all other components of the
exhaust system for heat damage.
Unleaded gasoline must be used to avoid con-
taminating the catalyst core.
50 State emission vehicles incorporate two mini
catalytic converters located after the exhaust mani-
folds and before the inline catalytic converter.
OPERATION
The catalytic converter captures and burns any
unburned fuel mixture exiting the combustion cham-
bers during the exhaust stroke of the engine. This
process aids in reducing emissions output.
REMOVAL
REMOVAL
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove the bolts from the crossover pipe to the
catalytic converter connection.
(4) Disconnect oxygen sensor wiring.
(5) Loosen the nuts from the clamp that hold the
catalytic converter to the exhaust pipe flange connec-
tion.
NOTE: Do not remove nut from T-Bolt. Only remove
nut far enough, so that the T end can be removed
from the clamp.
(6) Remove the T bolt end of the fastener, from the
clamp.
(7) Spread the clamp, and remove the catalytic
converter from the vehicle.
(8) Discard the clamp.
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.
REMOVAL
(1) Raise and support vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove clamps and nuts.
(4) Remove the catalytic converter.
INSPECTION
Look at the stainless steel body of the converter,
inspect for bulging or other distortion that could be a
result of overheating. If the converter has a heat
shield attached make sure it is not bent or loose.
If you suspect internal damage to the catalyst, tap-
ping the bottom of the catalyst with a rubber mallet
may indicate a damaged core.
INSTALLATION
INSTALLATION
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.
TURBOCHARGER TESTER 9022
11 - 6 EXHAUST SYSTEMDR
EXHAUST SYSTEM (Continued)

(1) Position the catalytic converter onto the
exhaust pipe flange connection. Tighten the nuts to
28 N´m (250 in. lbs.) torque.
(2) Install the muffler onto the catalytic converter
until the alignment tab is inserted into the align-
ment slot.
(3) Install the exhaust clamp at the muffler and
catalytic converter connection. Tighten the clamp
nuts to 54.2 N´m (40 ft. lbs.) torque.
(4) Connect oxygen sensor wiring.
(5) Lower the vehicle.
(6) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(7) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
INSTALLATION
(1) Assemble converter and clamps loosely in
place.
(2) Install the exhaust pipe onto exhaust mani-
folds, tighten 31 N´m (23 ft. lbs.).
(3) Tighten all clamp nuts to 52.2 N´m (40 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(6) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
EXHAUST PIPE
REMOVAL - 3.7L/4.7L/5.7L
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove exhaust pipe to manifold bolts, retain-
ers and nuts.
(4) Remove the clamp nuts.
(5) Remove the exhaust pipe (Fig. 4).
INSPECTION
Discard rusted clamps, broken or worn supports
and attaching parts. Replace a component with orig-
inal equipment parts, or equivalent. This will assure
proper alignment with other parts in the system and
provide acceptable exhaust noise levels.
INSTALLATION - 3.7L/4.7L/5.7L
(1) Position the exhaust pipe for proper clearance
with the frame and underbody parts. A minimum
clearance of 25.4 mm (1.0 in.) is required.
(2) Position the exhaust pipe to manifold. Install
the bolts, retainers and nuts. Tighten the nuts to 31
N´m (23 ft. lbs.) torque.
(3) Tighten the clamp nuts to 54.2 N´m (40 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
EXHAUST PIPE
REMOVAL - DIESEL
(1) Disconnect the battery negative cables.
(2) Raise and support the vehicle on a hoist.
(3) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(4) Remove the exhaust pipe-to-extension pipe
clamp. Separate the exhaust pipe and extension pipe.
(5) Remove the exhaust pipe-to-turbocharger elbow
clamp (Fig. 5).
(6) Remove the exhaust pipe from the transmis-
sion support (Fig. 5).
Fig. 4 Exhaust Pipe to Manifold Connection -
Typical
1 - BOLT
2 - RETAINER
3 - EXHAUST MANIFOLD
4 - NUT
5 - EXHAUST PIPE
DREXHAUST SYSTEM 11 - 7
CATALYTIC CONVERTER (Continued)

INSTALLATION
(1) Install the tailpipe into the muffler.
(2) Install the tailpipe hanger rods into the isola-
tors (Fig. 11)
(3) Install the exhaust clamp, align the exhaust
system, and tighten the clamp 48 N´m (35 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Connect the battery negative cables.
(6) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(7) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
TAILPIPE
REMOVAL
(1) Raise and support the vehicle.
(2) Saturate the clamp nuts with heat valve lubri-
cant. Allow 5 minutes for penetration.
(3) Disconnect the exhaust tailpipe support hanger
(Fig. 12).(4) Remove clamps and nuts.
(5) Remove the exhaust tailpipe.
INSPECTION
Discard rusted clamps, broken or worn supports
and attaching parts. Replace a component with orig-
inal equipment parts, or equivalent. This will assure
proper alignment with other parts in the system and
provide acceptable exhaust noise levels.
INSTALLATION
(1) Loosely assemble exhaust tailpipe to permit
proper alignment of all parts.
(2) Connect the support hangers.
(3) Position the exhaust tailpipe for proper clear-
ance with the underbody parts.
(4) Tighten all clamp nuts to 54.2 N´m (40 ft. lbs.)
torque.
(5) Lower the vehicle.
(6) Start the engine and inspect for exhaust leaks.
Reair exhaust leaks as necessary.
(7) Check the exhaust system for contact with the
body panels. A minimum of 25.4 mm (1.0 in.) is
required between the exhaust system components
and body/frame parts. Make the necessary adjust-
ments, if needed..
TURBOCHARGER SYSTEM
DIAGNOSIS AND TESTING - TURBOCHARGER
BOOST PRESSURE
NOTE: This diagnostic procedure is to be used with
the DRB IIITwhile test driving the vehicle under
normal load and driving conditions.
Low turbocharger boost pressure can cause poor
engine performance and driveability concerns. The
following procedure will test the turbocharger boost
pressure.
(1) Loosen clamps holding air inlet duct rubber
sleeve to the intake manifold and air inlet duct.
Remove rubber sleeve (Fig. 13).
(2) Position Special Tool 8462 onto air inlet duct
and intake manifold. Using the existing clamps
tighten to 8 N´m (72 in. lbs.).
(3) Install the 3447.5 kPa 500 psi (gray) Pressure
Transducer (part of OT-CH8520 Transducer Kit) into
Special Tool 8462.
(4) Connect the DRB IIItto the pressure trans-
ducer following the instructions supplied with the
DRB IIIt.
(5) Enter DRB IIItinto pressure reading mode
and test drive vehicle.
Fig. 12 TAILPIPE
1 - INSULATOR
2 - TAILPIPE
3 - CLAMP
4 - MUFFLER
5 - CLAMP
6 - INSULATOR
7 - INSULATOR
8 - INSULATOR
DREXHAUST SYSTEM 11 - 11
TAILPIPE - 5.9L DIESEL (Continued)

(6) Full load boost pressure at rated speed will be
158 - 186 kPa (23 - 27 psi.) depending on engine hp
rating.. If pressure readings are are not within this
range inspect for the following:
²Restricted air inlet system
²Leak in the charge air cooler system (Refer to 11
- EXHAUST SYSTEM/TURBOCHARGER SYSTEM/
CHARGE AIR COOLER AND PLUMBING - DIAG-
NOSIS AND TESTING)
²Turbocharger wastegate broken or misadjusted
²Restricted/high pressure drop across charge air
cooler
²Turbocharger damaged (Refer to 11 - EXHAUST
SYSTEM/TURBOCHARGER SYSTEM/TURBO-
CHARGER - INSPECTION)
TURBOCHARGER
DESCRIPTION
The turbocharger is an exhaust-driven super-
charger which increases the pressure and density of
the air entering the engine. With the increase of air
entering the engine, more fuel can be injected into
the cylinders, which creates more power during com-
bustion.
The turbocharger assembly consists of four (4)
major component systems (Fig. 14) (Fig. 15) :²Turbine section
²Compressor section
²Bearing housing
²Wastegate
Fig. 13 INTAKE MANIFOLD TO AIR INLET DUCT
RUBBER SLEEVE
1 - INTAKE MANIFOLD AIR INLET
2 - CLAMPS
3 - AIR INLET DUCT
4 - AIR INLET DUCT RUBBER SLEEVE
Fig. 14 Turbocharger Operation
1 - TURBINE SECTION
2 - EXHAUST GAS
3 - BEARING HOUSING
4 - COMPRESSOR SECTION
5 - INLET AIR
6 - COMPRESSED AIR TO ENGINE
7 - EXHAUST GAS
8 - EXHAUST GAS TO EXHAUST PIPE
Fig. 15 Turbocharger Wastegate Actuator
1 - TURBOCHARGER
2 - DIAPHRAGM
3 - WASTE GATE ACTUATOR
11 - 12 EXHAUST SYSTEMDR
TURBOCHARGER SYSTEM (Continued)

OPERATION
Exhaust gas pressure and energy drive the tur-
bine, which in turn drives a centrifugal compressor
that compresses the inlet air, and forces the air into
the engine through the charge air cooler and plumb-
ing. Since heat is a by-product of this compression,
the air must pass through a charge air cooler to cool
the incoming air and maintain power and efficiency.
Increasing air flow to the engine provides:
²Improved engine performance
²Lower exhaust smoke density
²Improved operating economy
²Altitude compensation
²Noise reduction.
The turbocharger also uses a wastegate (Fig. 16),
which regulates intake manifold air pressure and
prevents over boosting at high engine speeds. When
the wastegate valve is closed, all of the exhaust gases
flow through the turbine wheel. As the intake mani-
fold pressure increases, the wastegate actuator opens
the valve, diverting some of the exhaust gases away
from the turbine wheel. This limits turbine shaft
speed and air output from the impeller.
The turbocharger is lubricated by engine oil that is
pressurized, cooled, and filtered. The oil is delivered
to the turbocharger by a supply line that is tapped
into the oil filter head. The oil travels into the bear-
ing housing, where it lubricates the shaft and bear-
ings (Fig. 17). A return pipe at the bottom of the
bearing housing, routes the engine oil back to the
crankcase.
The most common turbocharger failure is bearing
failure related to repeated hot shutdowns with inad-
equate ªcool-downº periods. A sudden engine shut
down after prolonged operation will result in the
transfer of heat from the turbine section of the tur-
bocharger to the bearing housing. This causes the oil
to overheat and break down, which causes bearing
and shaft damage the next time the vehicle is
started.
Letting the engine idle after extended operation
allows the turbine housing to cool to normal operat-
ing temperature. The following chart should be used
as a guide in determining the amount of engine idle
time required to sufficiently cool down the turbo-
charger before shut down, depending upon the type
of driving and the amount of cargo.
Fig. 16 Wastegate Operation
1 - SIGNAL LINE
2 - EXHAUST BYPASS VALVE
3 - WASTEGATE
4 - EXHAUST
5 - TURBINE
DREXHAUST SYSTEM 11 - 13
TURBOCHARGER (Continued)

(9) Remove the turbocharger and gasket from the
exhaust manifold.
(10) If the turbocharger is not to be installed
immediately, cover the opening to prevent material
from entering into the manifold.
(11) If replacing the turbocharger, transfer the tur-
bocharger oil supply fitting to the new assembly.
Tighten fitting to 36 N´m (27 ft. lbs.).
(12) Clean and inspect the sealing surface.
CAUTION: The turbocharger is only serviced as an
assembly. Do not attempt to repair the turbocharger
as turbocharger and/or engine damage can result.
CLEANING
WARNING: To prevent damage or personal injury,
do not use a combustable cleaner to clean the tur-
bocharger.
Clean the turbocharger and exhaust manifold
mounting surfaces with a suitable scraper.
INSPECTION
Visually inspect the turbocharger and exhaust
manifold gasket surfaces. Replace stripped or eroded
mounting studs.
(1) Visually inspect the turbocharger for cracks.
The following cracks are NOT acceptable:
²Cracks in the turbine and compressor housing
that go completely through.
²Cracks in the mounting flange that are longer
than 15 mm (0.6 in.).
²Cracks in the mounting flange that intersect
bolt through-holes.
²Two (2) Cracks in the mounting flange that are
closer than 6.4 mm (0.25 in.) together.
(2) Visually inspect the impeller and compressor
wheel fins for nicks, cracks, or chips. Note: Some
impellers may have a factory placed paint mark
which, after normal operation, appears to be a crack.
Remove this mark with a suitable solvent to verify
that it is not a crack.
(3) Visually inspect the turbocharger compressor
housing for an impeller rubbing condition (Fig. 20).
Replace the turbocharger if the condition exists.
(4) Measure the turbocharger axial end play:
(a) Install a dial indicator as shown in (Fig. 21).
Zero the indicator at one end of travel.
(b) Move the impeller shaft fore and aft and
record the measurement. Allowable end play is
0.026 mm (0.0001 in.) MIN. and 0.127 mm (0.005
in.) MAX. If the recorded measurement falls out-
side these parameters, replace the turbocharger
assembly.(5) Measure the turbocharger bearing radial clear-
ance:
(a) Insert a narrow blade or wire style feeler
gauge between the compressor wheel and the hous-
ing (Fig. 22).
(b) Gently push the compressor wheel toward
the housing and record the clearance.
(c) With the feeler gauge in the same location,
gently push the compressor wheel away from the
housing and again record the clearance.
(d) Subtract the smaller clearance from the
larger clearance. This is the radial bearing clear-
ance.
(e) Allowable radial bearing clearance is 0.33
mm (0.013 in.) MIN. and 0.50 mm (0.020 in.) MAX.
If the recorded measurement falls outside these
specifications, replace the turbocharger assembly.
INSTALLATION
(1) Install the turbocharger. Apply anti-seize to the
studs and then tighten the turbocharger mounting
nuts to 43 N´m (32 ft. lbs.) torque.
Fig. 20 Inspect Compressor Housing for Impeller
Rubbing Condition
Fig. 21 Measure Turbocharger Axial End Play
DREXHAUST SYSTEM 11 - 15
TURBOCHARGER (Continued)