(4) Remove upper intake manifold. Refer to Group
11, Exhaust System and Intake Manifolds for proce-
dure.
(5) Remove cylinder head covers and spark plugs.
(6) Remove electrical connector from ignition coils.
(7) Using suitable socket and flex handle at crank-
shaft pulley retaining screw, turn engine so the num-
ber 1 piston is at Top Dead Center on the
compression stroke.
(8) Remove rocker arms with rocker shaft and
install a dummy shaft. The rocker arms should not
be disturbed and left on shaft.
(9) With air hose attached to spark plug adapter
installed in number 1 spark plug hole, apply 90 to
100 psi air pressure (620.5 to 689 kPa). This is to
hold valves in place while servicing components.
(10) Using Tool C-4682 or equivalent, compress
valve spring and remove retainer valve locks and
valve spring.
(11) The intake valve stem seals should be pushed
firmly and squarely over the valve guide using the
valve stem as guide.Do Not Forceseal against top
of guide. When installing the valve retainer locks,
compress the springonly enoughto install the
locks.
CAUTION: Do not pinch seal between retainer and
top of valve guide.
(12) Follow the same procedure on the remaining 5
cylinders using the firing sequence 1-2-3-4-5-6.Make
sure piston in cylinder is at TDC on the valve
spring that is being covered.
(13) Remove spark plug adapter tool.
(14) Remove dummy shaft and install rocker shaft
assembly and tighten screws to 28 N´m (250 in. lbs.).
(15) Install cylinder head covers tighten screws to
14 N´m (120 in. lbs.) and electrical connector to igni-
tion coils.
(16) Install Intake Manifold. Refer to Group 11,
Exhaust System and Intake Manifold for procedure.
(17) Connect negative cable to battery.
CYLINDER HEAD COVER
REMOVAL
NOTE: The cylinder head cover can be either an
isolated type (Fig. 32) or a non-isolated type.
FRONT CYLINDER HEAD COVER
(1) Disconnect ignition cables from spark plugs.
(2) Disconnect crankcase vent hose from cylinder
head cover.
(3) Remove front cylinder head cover bolts.
(4) Remove cylinder head cover and gasket.REAR CYLINDER HEAD COVER
(1) Disconnect negative cable from battery.
(2) Remove Wiper Unit. Refer to Group 8K, Wind-
shield Wipers and Washers for procedure.
(3) Remove intake manifold upper plenum. Refer
to Group 11, Exhaust System and Intake Manifold
for procedure.
(4) Disconnect PCV hose from cylinder head cover.
(5) Remove rear cylinder head cover bolts
(6) Remove cylinder head cover and gasket.
INSTALLATION
FRONT CYLINDER HEAD COVER
(1) Clean cylinder head and cover mating surfaces.
Inspect cylinder head cover surface for flatness.
Replace gasket as necessary.
(2) Install cylinder head cover and bolts.
(3) Tighten cylinder head cover bolts to the follow-
ing specifications:
²Non±isolatedcylinder head cover to 12 N´m
(105 in. lbs.).
²Isolatedcylinder head cover to 10 N´m (90 in.
lbs.) (Fig. 32).
(4) Connect crankcase vent hose.
(5) Connect ignition cables to spark plugs.
REAR CYLINDER HEAD COVER
(1) Clean cylinder head and cover mating surfaces.
Inspect cylinder head cover surface for flatness.
Replace gasket as necessary.
(2) Install cylinder head cover and bolts.
(3) Tighten cylinder head cover bolts to the follow-
ing specifications:
Fig. 32 Cylinder Head CoverÐIsolated Type
NS3.3/3.8L ENGINE 9 - 107
REMOVAL AND INSTALLATION (Continued)
(7) Inspect push rods and replace worn or bent
rods.
(8) Install push rods, rocker arm and shaft assem-
blies with the stamped steel retainers in the four
positions, tighten to 28 N´m (250 in. lbs.) (Fig. 36).
(9) Place new cylinder head cover gaskets in posi-
tion and install cylinder head covers. Tighten to 12
N´m (105 in. lbs.).
INTAKE MANIFOLD SEALING
The intake manifold gasket is a one-piece stamped
steel gasket with a sealer applied from the manufac-
turer. This gasket has end seals incorporated with it.
WARNING: INTAKE MANIFOLD GASKET IS MADE
OF VERY THIN METAL AND MAY CAUSE PER-
SONAL INJURY, HANDLE WITH CARE.
(1) Clean all surfaces of cylinder block and cylin-
der heads.
(2) Place a drop (about 1/4 in. diameter) of Mopart
Silicone Rubber Adhesive Sealant or equivalent, onto
each of thefourmanifold to cylinder head gasket
corners (Fig. 37).
(3) Carefully install the intake manifold gasket
(Fig. 38). Torque end seal retainer screws to 12 N´m
(105 in. lbs.).(4) Install intake manifold and (8) bolts and torque
to 1 N´m (10 in. lbs.). Then tighten bolts to 22 N´m
(200 in. lbs.) in sequence shown in (Fig. 39). Then
tighten again to 22 N´m (200 in. lbs.). After intake
manifold is in place,inspect to make sure seals
are in place.Refer to Group 11, Exhaust System
and Intake Manifold to complete intake manifold
installation.
(5) Install exhaust manifolds and tighten bolts to
27 N´m (20 ft. lbs.) and nuts to 20 N´m (15 ft. lbs.).
(6) Adjust spark plugs to specification in Group 8,
Electrical Section and install the plugs.
VALVES AND VALVE SPRINGS
REMOVAL
(1) With cylinder head removed, compress valve
springs using Valve Spring Compressor Tool
C-3422-B with adapter 6412 as shown in (Fig. 40).
(2) Remove valve retaining locks, valve spring
retainers, valve stem seals and valve springs.
Fig. 36 Rocker Arm Shaft Retainers
Fig. 37 Intake Manifold Gasket Sealing
Fig. 38 Intake Manifold Gasket Retainers
Fig. 39 Intake Manifold Removal and Installation
NS3.3/3.8L ENGINE 9 - 109
REMOVAL AND INSTALLATION (Continued)
EXHAUST SYSTEM AND INTAKE MANIFOLD
CONTENTS
page page
GENERAL INFORMATION
CATALYTIC CONVERTERS................. 1
EXHAUST FLEX-JOINT COUPLING........... 2
EXHAUST GAS RECIRCULATION (EGR)....... 2
EXHAUST SYSTEM....................... 1
HEAT SHIELDS.......................... 2
DESCRIPTION AND OPERATION
INTAKE/EXHAUST MANIFOLDÐ2.4L ENGINE . . 3
INTAKE/EXHAUST MANIFOLDÐ3.0L ENGINE . . 3
INTAKE/EXHAUST MANIFOLDÐ3.3/3.8L
ENGINES............................. 3
DIAGNOSIS AND TESTING
EXHAUST SYSTEM....................... 3REMOVAL AND INSTALLATION
EXHAUST MANIFOLDÐ2.4L ENGINE........ 8
EXHAUST MANIFOLDÐ3.0L ENGINE....... 11
EXHAUST MANIFOLDSÐ3.3/3.8L ENGINE . . . 16
EXHAUST PIPES, MUFFLERS AND TAILPIPES . 4
INTAKE MANIFOLD LOWERÐ2.4L ENGINE.... 6
INTAKE MANIFOLDÐ3.0L ENGINE.......... 8
INTAKE MANIFOLDÐ3.3/3.8L ENGINE...... 12
UPPER INTAKE MANIFOLDÐ2.4L ENGINE.... 4
CLEANING AND INSPECTION
EXHAUST MANIFOLD.................... 17
INTAKE MANIFOLD...................... 17
SPECIFICATIONS
TORQUE CHART........................ 18
GENERAL INFORMATION
EXHAUST SYSTEM
The exhaust systems are produced in several con-
figurations, depending on engine and vehicle (Fig. 1).
AWD vehicles have a catalytic converter mounted
heat shield. The tailpipes, mufflers, and resonators
are tuned to each vehicle/powertrain combination.
CATALYTIC CONVERTERS
There is no regularly scheduled maintenance on
any Chrysler catalytic converter. If damaged, the con-
verter must be replaced.CAUTION: Due to exterior physical similarities of
some catalytic converters with pipe assemblies,
extreme care should be taken with replacement
parts. There are internal converter differences
required in some parts of the country.
The combustion reaction caused by the catalyst
releases additional heat in the exhaust system. Caus-
ing temperature increases in the area of the reactor
under severe operating conditions. Such conditions
can exist when the engine misfires or otherwise does
not operate at peak efficiency.Do notremove spark
plug wires from plugs or by any other means short
out cylinders of the exhaust system if equipped with
Fig. 1 Exhaust SystemÐTypical (All Vehicles)
NSEXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 1
A defective fuel injection pump, defective fuel tim-
ing solenoid or misadjusted mechanical pump timing
can cause starting problems or prevent the engine
from revving up. It can also cause:
²Engine surge at idle
²Rough idle (warm engine)
²Low power
²Excessive fuel consumption
²Poor performance
²Low power
²Black smoke from the exhaust
²Blue or white fog like exhaust
²Incorrect idle or maximum speed
The electronically controlled fuel pump has no
mechanical governor like older mechanically con-
trolled fuel pumps. Do not remove the top cover of
the fuel pump, or the screws fastening the wiring
pigtail to the side of the pump.The warranty of
the injection pump and the engine may be void
if those seals have been removed or tampered
with.
FUEL SUPPLY RESTRICTIONS
LOW±PRESSURE LINES
Restricted or Plugged supply lines or fuel filter can
cause a timing fault that will cause the PCM to oper-
ate the engine in a ªLimp Homeº mode. See the
introduction of the Fuel Injection System in this
group for more information on the Limp Home mode.
Fuel supply line restrictions can cause starting prob-
lems and prevent the engine from revving up. The
starting problems include; low power and blue or
white fog like exhaust. Test all fuel supply lines for
restrictions or blockage. Flush or replace as neces-
sary. Bleed the fuel system of air once a fuel supply
line has been replaced. Refer to the Air Bleed Proce-
dure section of this group for procedures.
HIGH±PRESSURE LINES
Restricted (kinked or bent) high±pressure lines can
cause starting problems, poor engine performance
and black smoke from exhaust.
Examine all high±pressure lines for any damage.
Each radius on each high±pressure line must be
smooth and free of any bends or kinks.
Replace damaged, restricted or leaking high±pres-
sure fuel lines with the correct replacement line.
CAUTION: The high±pressure fuel lines must be
clamped securely in place in the holders. The lines
cannot contact each other or other components. Do
not attempt to weld high±pressure fuel lines or to
repair lines that are damaged. Only use the recom-
mended lines when replacement of high±pressure
fuel line is necessary.
FUEL SHUTDOWN SOLENOID TEST
Since diesel fuel injection does not use spark plugs
to start combustion, the only way to stop the engine
is to cut off the fuel supply. This is done with the
Fuel Shutdown Solenoid. If the engine cranks, but
refuses to start, it may be caused by a defective fuel
shutdown solenoid.
The fuel shutdown solenoid is not controlled
or operated by the PCM.Voltage to operate the
solenoid is supplied from the ignition (key) switch.
NOTE: Although the fuel shutdown solenoid is not
operated by the PCM, if the Fuel Shutdown Solenoid
has been disconnected, and the key turned on, the
PCM will sense that the solenoid is not in the circuit,
and will switch to a ªLimp Homeº mode. After recon-
necting the solenoid, the PCM will have to be reset
by clearing the codes with the DRBIII scan tool, or
disconnecting the vehicle's battery for several min-
utes. The DRBIII scan tool is the preferred method
for resetting the PCM. Refer to the 1998 GS 2.5L Die-
sel Powertrain Diagnostic Manual for procedure.
The fuel shutdown (shut±off) solenoid is used to
electrically shut off the diesel fuel supply to the high-
±pressure fuel injection pump. The solenoid is
mounted to the rear of the injection pump (Fig. 23).
The solenoid controls starting and stopping of the
engine regardless of the position of the accelerator
pedal. When the ignition (key) switch is OFF, the sole-
noid is shut off and fuel flow is not allowed to the fuel
injection pump. When the key is placed in the ON or
Fig. 23 Fuel Shutdown Solenoid Location
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 13
DIAGNOSIS AND TESTING (Continued)
IGNITION COILÐPCM OUTPUTÐ2.0L ENGINE
Refer to the Ignition Coil for 2.4/3.0/3.3/3.8L
engines under Description and Operation in the Fuel
Injection System section of group 14 for more infor-
mation.
MALFUNCTION INDICATOR (CHECK ENGINE)
LAMPÐPCM OUTPUTÐ2.0L ENGINE
Refer to the Malfunction Indicator Lamp for 2.4/
3.0/3.3/3.8L engines under Description and Operation
in the Fuel Injection System section of group 14 for
more information.
RADIATOR FAN CONTROL MODULEÐPCM
OUTPUTÐ2.0L ENGINE
Refer to the Radiator Fan Control Module for 2.4/
3.0/3.3/3.8L engines under Description and Operation
in the Fuel Injection System section of group 14 for
more information.
SPEED CONTROL SOLENOIDSÐPCM OUTPUTÐ
2.0L ENGINE
Refer to the Speed Control Solenoids for 2.4/3.0/3.3/
3.8L engines under Description and Operation in the
Fuel Injection System section of group 14 for more
information.
TACHOMETERÐPCM OUTPUTÐ2.0L ENGINE
Refer to the Tachometer for 2.4/3.0/3.3/3.8L engines
under Description and Operation in the Fuel Injec-
tion System section of group 14 for more information.
THROTTLE BODYÐ2.0L ENGINE
Refer to the Throttle Body for 2.4/3.0/3.3/3.8L
engines under Description and Operation in the Fuel
Injection System section of group 14 for more infor-
mation.
DIAGNOSIS AND TESTING
VISUAL INSPECTIONÐSOHC
Before diagnosing or servicing the fuel injection
system, perform a visual inspection for loose, discon-
nected, or misrouted wires and hoses. A thorough
visual inspection that includes the following checks
saves unnecessary test and diagnostic time.
(1) Inspect the battery connections. Clean corroded
terminals.
(2) Check the 2 PCM 40-way connector for
stretched wires on pushed out terminals
(3) Open the Power Distribution Center (PDC).
Check for blown fuses. Ensure the relays and fuses
are fully seated in the PDC. A label on the underside
of the PDC cover shows the locations of each relay
and fuse.
(4) Verify the throttle cable operates freely.
(5) Check the electrical connections at the idle air
control motor and throttle position sensor.
(6) Check hose connections between the PCV
valve, vacuum port - intake manifold and the oil sep-
arator (Fig. 13).
(7) Inspect the electrical connections at the MAP
sensor/intake air temperature sensor and the (Fig.
14).
(8) Inspect the fuel injector electrical connections
(Fig. 15).
(9) Inspect the ignition coil electrical connector.
Ensure the spark plug insulators are firmly seated
over the spark plugs (Fig. 16).
(10) Check the electrical connection to the radiator
fan.
(11) Inspect for corrosion on the electrical connec-
tions at the starter motor solenoid. Check the ground
cable connection below the starter motor (Fig. 17).
(12) Inspect the air cleaner filter element. Replace
as necessary. Check the air induction system for
restrictions.
Fig. 10 Ignition CoilÐ2.0L engine
Fig. 11 Throttle BodyÐ2.0L engine
14 - 36 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DESCRIPTION AND OPERATION (Continued)