CAUTION: Avoid application of rust prevention com-
pounds or undercoating materials to exhaust sys-
tem floor pan exhaust heat shields. Light overspray
near the edges is permitted. Application of coating
will result in excessive floor pan temperatures and
objectionable fumes.

The diesel engine exhaust system consists of an

engine exhaust manifold, turbocharger, exhaust pipe,
resonator, extension pipe (if needed), muffler and
exhaust tailpipe (Fig. 1).

The exhaust system must be properly aligned and

secured to prevent stress, leakage and body contact.
The exhaust components should be kept a minimum
of 25.4 mm (1.0 in.) away from the body and frame.
If the system contacts any body panel, it may amplify
objectionable noises from the engine or body.

EXHAUST SYSTEM

11 - 1

DIAGNOSIS AND TESTING - DIESEL ENGINE

EXHAUST SYSTEM DIAGNOSIS CHART

CONDITION

POSSIBLE CAUSE

CORRECTION

EXCESSIVE EXHAUST NOISE OR

LEAKING EXHAUST GASES

1. Leaks at pipe joints.

1. Tighten/replace clamps/bolts at
leaking joints.

2. Rusted or expanded muffler.

2. Replace muffler. Inspect exhaust
system.

3. Broken or rusted 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/replace exhaust manifold
to cylinder head bolts.

7. Turbocharger mounting flange
cracked.

7. Remove turbocharger and in-
spect.

8. Restriction in exhaust system.

8. Remove restriction, if possible.
Replace restricted part if neces-
sary.

Fig. 1 Exhaust System

1 - TURBOCHARGER
2 - HEAT SHIELD
3 - CLAMP
4 - EXHAUST PIPE
5 - FRONT INSULATOR
6 - NUT

7 - WASHER
8 - INSULATOR
9 - BOLT
10 - MUFFLER/CATALYTIC CONVERTER ASSEMBLY
11 - TAILPIPE

11 - 2

EXHAUST SYSTEM

CATALYTIC CONVERTER

REMOVAL

(1) Raise and support the vehicle.
(2) Saturate the clamp nuts with heat valve lubri-

cant. Allow 5 minutes for penetration. Remove the
rear clamp. (Fig. 1)

(3) Saturate the clamp nuts with heat valve lubri-

cant. Allow 5 minutes for penetration. Remove the
front clamp.

(4) Remove the cataylic converter and muffler

assembly from the isolators.

(5) Seperat the cataylic converter and muffler

assembly from the tailpipe and the exhaust pipe.

(6) Remove the cataylic converter and muffler

assembly and isolators from the vehicle.

(7) Remove the bolt, nut and front isolator from

the cataylic converter and muffler assembly.

(8) Remove the rear isolator from the cataylic con-

verter and muffler assembly.

(9)

INSTALLATION

(1) Install bolt, front isolator and nut (Fig. 1).
(2) Install rear insulator onto the cataylic con-

verter and muffler assembly

(3) Position the cataylic conveter and muffler

assembly into the exhaust pipe and tailpipe until
alignment tab is inserted into the alignment slot.

(4) Install the front and rear insulators.
(5) Install the real clamp.
(6) Install the front clamp.
(7) Lower vehicle.
(8) Start the vehicle and inspect for exhaust leaks.

Repair exhaust leaks as necessary.

(9) Check the exhaust system for contact with the

body panels. Make necessary adjustments, if neces-
sary.

EXHAUST PIPE

REMOVAL

(1) Raise and support the vehicle.
(2) Saturate the clamp nuts with heat valve lubri-

cant. Allow 5 minutes for penetration. Remove the
front and rear clamp (Fig. 1).

(3) Remove the mounting bracket nuts.
(4) Remove the exhaust pipe.

INSTALLATION

(1) Position the exhaust pipe into the exhaust pipe

into the cataylic converter and muffler assembly
until alignment tab is inserted into the alignment
slot.

(2) Install mounting bracket and nuts (Fig. 1).
(3) Install clamp.

(4) Lower the vehicle.
(5) Start the vehicle and inspect for exhaust leaks.

Repair exhaust leaks as necessary.

(6) Check the exhaust system for contact with the

body panels. Make necessary adjustments, if neces-
sary.

TAILPIPE

REMOVAL

(1) Raise and support the vehicle.
(2) Saturate the clamp nuts with heat valve lubri-

cant. Allow 5 minutes for penetration (Fig. 1).

(3) Remove the clamp.
(4) Remove the tailpipe and insulator form the

vehicle

(5) Remove the insulator from the tailpipe.

INSTALLATION

(1) Position the tail pipe into the cataylic converter

and muffler assembly until alignment tab is inserted
into the alignment slot.

(2) Install the insulator.
(3) Install the clamp.
(4) Lower the vehicle.
(5) Start the vehicle and inspect for exhaust leaks.

Repair exhaust leaks as necessary.

(6) Check the exhaust system for contact with the

body panels. Make necessary adjustments, if neces-
sary.

TURBOCHARGER SYSTEM

DESCRIPTION

CAUTION: The turbocharger is a performance part
and must not be tampered with. The boost pressure
bracket is an integral part of the turbocharger. Tam-
pering with the boost pressure components can
reduce durability by increasing cylinder pressure
and thermal loading due to incorrect inlet and
exhaust manifold pressure. Poor fuel economy and
failure to meet regulatory emissions laws may
result. Increasing the turbocharger boost WILL NOT
increase engine power.

The turbocharger used on this vehicle is of the

variable turbine type. These turbochargers use the
entire exhaust energy to boost efficiency of the turbo-
charger and the engine.

The advantages of a turbocharger with variable

turbine geometry are:

• Higher charge pressure already in the lower and

in upper engine speed ranges.

• Higher torque as a result of improved cylinder

charge.

EXHAUST SYSTEM

11 - 3

• Reduction in exhaust emissions as a result of an

improvement in the air supply of the engine.

• Increased power output as a result of the higher

charge pressure combined with a reduced exhaust
backpressure and thus improved charge cycle.

OPERATION

The exhaust gases of the engine are directed

through the exhaust manifold into the turbine hous-
ing onto the turbine wheel (Fig. 2). The flow energy
of the exhaust gases cause the turbine wheel to
rotate. Consequently, the compressor wheel, which is
connected through the turbine shaft with the turbine
wheel, is driven at the same speed. The fresh air
inducted by the compressor wheel is compressed and
passed to the engine (Fig. 2).

The charge pressure is controlled by varying the

position of the guide vanes (Fig. 2). The guide stud of
the control linkage of the boost pressure actuator
turns the adjusting ring in the turbine housing (Fig.
2). As a result, all the guide vanes whose guide studs
likewise mesh into the adjusting ring, are also
turned (Fig. 2).

At low speeds, the flow cross-section is reduced by

closing the guide vanes (Fig. 2). Consequently the
speed at which the exhaust gas impacts on the tur-
bine wheel is increased, as a result of which the
speed of the turbocharger and thus the charge pres-
sure rises.

At high engine speeds the guide vanes are increas-

ingly opened and the flow cross-section is thus
enlarged, as a result of which the speed of the turbo-
charger reduces and the charge pressure drops.

CHARGE AIR COOLER AND
PLUMBING

DESCRIPTION

The charge air system consists of the charge air

cooler and charge air cooler piping.

The charge air cooler is a heat exchanger that uses

air flow from vehicle motion to dissipate heat from
the intake air. As the turbocharger increases air
pressure, the air temperature increases. Lowering
the intake air temperature increases engine effi-
ciency and power.

Fig. 2 TURBOCHARGER COMPONENTS

1 - COMPRESSOR HOUSING
2 - GUIDE VANE
3 - GUIDE STUD OF GUIDE VANE
4 - GUIDE STUD OF CONTROL LINKAGE
5 - CONTROL LINKAGE
6 - ADJUSTING RING
7 - TURBINE HOUSING
8 - BOOST PRESSURE CONTROL UNIT
1A - EXHAUST GASES TO TURBINE WHEEL
2A - TURBO INLET (FRESH AIR)
3A - TURBO OUTLET (COMPRESSED AIR)
4A - EXHAUST OUTLET

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EXHAUST SYSTEM

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