(2) Disconnect the inlet air temperature sensor
(Fig. 16).
(3) Remove the inlet hose to throttle body.
(4) Remove the bolt for air box at upper radiator
cross member.
(5) Pull air box up and off over the single locating
pin.
(6) Remove air box from vehicle
INSTALLATION
(1) Install air box into vehicle and onto the locat-
ing pin.
(2) Install bolt to hold air box to the upper radia-
tor cross member.
(3) Install the inlet hose to the throttle body.
(4) Connect the inlet air temperature sensor (Fig.
16).
(5) Connect the negative battery cable.
CYLINDER HEAD
DESCRIPTION
The aluminum cylinder heads (Fig. 17) are
designed to create high flow combustion chambers to
improve performance, while minimizing the change
to the burn rate in the chamber. The cylinder head
incorporates the combustion chamber. Two valves
per-cylinder are used with inserted valve seats and
guides. A multi-layer steel (MLS) type gasket is used
between the cylinder head and engine block.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant 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 (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING). An
engine cylinder head gasket leaking between adja-
cent cylinders will result in approximately 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.
Fig. 16 Inlet Air Temperature Sensor
9 - 102 ENGINE 3.3/3.8LRS
AIR CLEANER HOUSING (Continued)
46) (Refer to 9 - ENGINE - SPECIFICATIONS). If
the cylinder walls are badly scuffed or scored, the
cylinder block should be replaced, and new pistons
and rings fitted.
Measure the cylinder bore at three levels in direc-
tions A and B (Fig. 46). Top measurement should be
10 mm (3/8 in.) down and bottom measurement
should be 10 mm (3/8 in.) up from bottom of bore.
(Refer to 9 - ENGINE - SPECIFICATIONS).
HYDRAULIC LIFTERS (CAM IN
BLOCK)
DESCRIPTION
The hydraulic lifters are a roller type design and
are positioned in the cylinder block. The lifters are
aligned and retained by a yoke and a retainer (Fig.
48).
Lifter alignment is maintained by machined flats
on lifter body. Lifters are fitted in pairs into six
aligning yokes. The aligning yokes are secured by a
yoke retainer (Fig. 48).
DIAGNOSIS AND TESTING - HYDRAULIC
LIFTERS
HYDRAULIC LIFTERS DIAGNOSIS - PRELIMINARY
STEP
Before disassembling any part of the engine to cor-
rect lifter noise, check the engine oil pressure. (Referto 9 - ENGINE/LUBRICATION - DIAGNOSIS AND
TESTING)
Check engine oil level. The oil level in the pan
should never be above the MAX mark on dipstick, or
below the MIN mark. Either of these two conditions
could cause noisy lifters.
OIL LEVEL TOO HIGH
If oil level is above the MAX mark on dipstick, it is
possible for the connecting rods to dip into the oil
while engine is running and create foaming. Foam in
oil pan would be fed to the hydraulic lifters by the oil
pump causing them to become soft and allow valves
to seat noisily.
OIL LEVEL TOO LOW
Low oil level may allow pump to take in air which
when fed to the lifters it causes them to become soft
and allows valves to seat noisily. Any leaks on intake
side of pump, through which air can be drawn, will
create the same lifter noise. Check the lubrication
system from the intake strainer to the oil pump
cover, including the relief valve retainer cap. When
lifter noise is due to aeration, it may be intermittent
or constant, and usually more than one lifter will be
noisy. When oil level and leaks have been corrected,
the engine should be operated at fast idle to allow all
of the air inside of the lifters to be bled out.
VALVE TRAIN NOISE
To determine source of valve train noise, operate
engine at idle with cylinder head covers removed and
listen for source of the noise.
NOTE: Worn valve guides or cocked springs are
sometimes mistaken for noisy lifters. If such is the
case, noise may be dampened by applying side
thrust on the valve spring. If noise is not apprecia-
bly reduced, it can be assumed the noise is in the
tappet. Inspect the rocker arm push rod sockets
and push rod ends for wear.
Valve lifter noise ranges from light noise to a
heavy click. A light noise is usually caused by exces-
sive leak-down around the unit plunger which will
necessitate replacing the lifter, or by the plunger par-
tially sticking in the lifter body cylinder. A heavy
click is caused either by a lifter check valve not seat-
ing, or by foreign particles becoming wedged between
the plunger and the lifter body causing the plunger
to stick in the down position. This heavy click will be
accompanied by excessive clearance between the
valve stem and rocker arm as valve closes. In either
case, lifter assembly should be removed for inspec-
tion.
Fig. 46 Checking Cylinder Bore Size
9 - 116 ENGINE 3.3/3.8LRS
ENGINE BLOCK (Continued)
RIGHT MOUNT
REMOVAL
(1) Remove air cleaner housing lid and clean air
hose from throttle body.
(2) Remove air cleaner element and housing.
(3) Disconnect make-up air hose from cylinder
head cover.
(4) Remove the load on the right engine mount by
carefully supporting the engine assembly with a floor
jack.
(5) Disconnect electrical harness support clips from
engine mount bracket.
(6) Remove the bolts attaching the engine mount
to the frame rail (Fig. 94).
(7) Remove the three bolts attaching the engine
mount to the engine bracket (Fig. 94).
(8) Remove the right engine mount (Fig. 94).
INSTALLATION
(1) Install engine bracket (if removed). Tighten
bolts to 33 N´m (24 ft. lbs.).
(2) Position right engine mount and install frame
rail to mount bolts (Fig. 94). Tighten bolts to 68 N´m
(50 ft. lbs.).
(3) Install the mount to engine bracket bolts and
tighten to 54 N´m (40 ft. lbs.). (Fig. 94)
(4) Connect electrical harness support clips to
engine mount bracket.
(5) Remove jack from under engine.
(6) Connect make-up air hose to cylinder head
cover.
(7) Install air cleaner housing and element.
(8) Install air cleaner housing lid and clean air
tube to throttle body.
LUBRICATION
DESCRIPTION
The lubrication system is a full flow filtration pres-
sure feed type. The oil pump is mounted in the tim-
ing chain cover and is driven by the crankshaft
OPERATION
Oil from the oil pan is pumped by a internal gear
type oil pump directly coupled to the crankshaft. The
pressure is regulated by a relief valve located in the
timing chain cover. The oil is pumped through an oil
filter and feeds a main oil gallery. This oil gallery
feeds oil under pressure to the main and rod bear-
ings, camshaft bearings. Passages in the cylinder
block feed oil to the hydraulic lifters and rocker shaft
brackets which feeds the rocker arm pivots (Fig. 95).
DIAGNOSIS AND TESTING - ENGINE OIL
PRESSURE
(1) Disconnect and remove oil pressure switch
(Refer to 9 - ENGINE/LUBRICATION/OIL PRES-
SURE SENSOR/SWITCH - REMOVAL).
(2) Install Special Tools C-3292 Gauge with 8406
Adaptor. For Special Tool identification, (Refer to 9 -
ENGINE - SPECIAL TOOLS).
(3) Start engine and record oil pressure. Refer to
Oil Pressure in Engine Specifications for the correct
pressure (Refer to 9 - ENGINE - SPECIFICATIONS).
Fig. 94 Right Engine Mount
1 - RIGHT ENGINE MOUNT
2 - BOLT - MOUNT TO FRAME RAIL
3 - BOLT - MOUNT TO ENGINE
4 - ENGINE MOUNT BRACKET
5 - RIGHT FRAME RAIL
9 - 138 ENGINE 3.3/3.8LRS
STANDARD PROCEDURE - INTAKE MANIFOLD
VACUUM PORT REPAIR
The composite intake manifold vacuum ports can
be repaired. Although, if the manifold plenum cham-
ber is damaged or cracked, the manifold must be
replaced.
To repair a broken or damaged vacuum nipple
(port) on the composite intake manifold, perform the
following procedure:
PARTS REQUIRED TOOLS REQUIRED
´ Brass Nipple ± 1/49
O.D. x 1/89pipe thread
(LDP/Speed Control Port)´ Pipe Tap ± 1/89-18
NPT
´ Drill Bit ± 11/329
´ File/Sandpaper
´ Brass Nipple ± 1/29
O.D. x 1/49pipe thread
(Brake Booster Port)´ Pipe Tap ± 1/49-18
NPT
´ Drill Bit ± 7/169
´ File/Sandpaper
NOTE: While performing this procedure, avoid get-
ting the manifold material residue into the plenum
chamber.
(1) File or sand the remaining port back until a
flat surface is obtained (plane normal to nipple (port)
axis).
(2) Drill out the nipple (port) base using a 7/16º
(brake booster port) or 11/32º (LDP/speed control port
) drill bit (Fig. 114).
(3) Using a 1/4º±18 NPT (brake booster port) or
1/8º±18 NPT (LDP/speed control port ) pipe tap, cut
internal threads (Fig. 114). Use caution to start tap
in a axis same as original nipple.
(4) Apply MopartThread Sealant to threads of
repair nipple(s).
(5) Install repair nipple(s). Do not over torque
repair nipple(s).
REMOVAL - UPPER INTAKE MANIFOLD
(1) Disconnect battery negative cable.
(2) Disconnect inlet air temperature (IAT) sensor
electrical connector.
(3) Remove air inlet resonator to throttle body
hose assembly.
(4) Disconnect throttle and speed control cables
from throttle body (Refer to 14 - FUEL SYSTEM/
FUEL INJECTION/THROTTLE CONTROL CABLE -
REMOVAL).
(5) Disconnect make-up air hose support clip from
throttle cable bracket.(6) Disconnect the automatic idle speed (AIS)
motor and throttle position sensor (TPS) wiring con-
nectors from throttle body.
(7) Disconnect the manifold absolute pressure
(MAP) sensor electrical connector.
(8) Disconnect the vapor purge vacuum hose from
throttle body.
(9) Disconnect the PCV hose (Fig. 115).
(10) Remove the power steering reservoir attach-
ing bolts and only loosen the nut (Fig. 116). Lift res-
ervoir up to disengage lower mount from stud. Set
reservoir aside.Do notdisconnect hose.
(11) Disconnect the brake booster and leak detec-
tion pump (LDP) hoses from intake manifold (Fig.
117).
(12) Remove intake manifold bolts and remove the
manifold (Fig. 118).
(13) Cover the lower intake manifold with a suit-
able cover while the upper manifold is removed.
(14) Clean and inspect the upper intake manifold
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANI-
FOLD - CLEANING) and (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - INSPECTION).
CLEANING
(1) Discard gasket(s).
(2) Clean all sealing surfaces.
Fig. 114 Intake Manifold Port Repair
1 - BRAKE BOOSTER PORT = 1/49±18 NPT PIPE TAP
1 - LDP/SPEED CONTROL PORT = 1/89±18 NPT PIPE TAP
2 - DRILL BIT = 7/169BRAKE BOOSTER PORT
2 - DRILL BIT = 11/329LDP/SPEED CONTROL PORT
3 - INTAKE MANIFOLD
9 - 148 ENGINE 3.3/3.8LRS
INTAKE MANIFOLD - UPPER (Continued)
(5) Connect the MAP sensor electrical connector.
(6) Connect the brake booster and LDP vacuum
hose to intake manifold (Fig. 117).CAUTION: The special screws used for attaching
the EGR tube and power steering reservoir to the
manifold must be installed slowly using hand tools
only. This requirement is to prevent the melting of
material that causes stripped threads. If threads
become stripped, an oversize repair screw is avail-
able. For more information and procedure (Refer to
9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD - STAN-
DARD PROCEDURE - MANIFOLD STRIPPED
THREAD REPAIR).
(7) Install the power steering reservoir (Fig. 116).
Tighten screws to manifold to 5.6 N´m (50 in. lbs.).
(8) Connect throttle and speed control cables to
throttle body (Refer to 14 - FUEL SYSTEM/FUEL
INJECTION/THROTTLE CONTROL CABLE -
INSTALLATION)
(9) Attach make up air hose clip into the hole in
the throttle cable bracket.
(10) Connect the wiring connectors to the throttle
position sensor (TPS) and Automatic Idle Speed (AIS)
motor.
(11) Install air cleaner and air inlet hose assembly.
(12) Connect the inlet air temperature (IAT) sen-
sor electrical connector.
(13) Connect battery negative cable.
INTAKE MANIFOLD - LOWER
REMOVAL - LOWER INTAKE MANIFOLD
(1) Perform fuel system pressure release procedure
(before attempting any repairs).(Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - STANDARD
PROCEDURE)
(2) Drain the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
(3) Remove the upper intake manifold. (Refer to 9
- ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL)
(4) Remove the fuel line. (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/FUEL LINES - STANDARD
PROCEDURE) (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/QUICK CONNECT FITTING - STAN-
DARD PROCEDURE)
(5) Remove ignition coil and bracket (Fig. 120).
(6) Disconnect heater supply hose and engine cool-
ant temperature sensor (Fig. 121).
(7) Disconnect the fuel injector wire harness.
(8) Remove the fuel injectors and rail assembly
(Fig. 120).
(9) Remove radiator upper hose.
(10) Remove the intake manifold bolts.
(11) Remove lower intake manifold (Fig. 122).
Fig. 118 INTAKE MANIFOLD - UPPER
1 - BOLT
2 - MAP SENSOR
3 - SCREW
4 - MANIFOLD - UPPER
5 - WIRE HARNESS
6 - GASKET (3 PER CYL. BANK)
Fig. 119 UPPER MANIFOLD TIGHTENING
SEQUENCE
9 - 150 ENGINE 3.3/3.8LRS
INTAKE MANIFOLD - UPPER (Continued)
(5) Apply the park brake and start the engine.
(6) With transmission in Park or Neutral, raise
engine speed to 2000 RPM. Monitor the pressure
readings on the DRBIIIt. Back pressure should not
exceed specified limit. Refer to specification in table
below EXHAUST BACK PRESSURE LIMITS.
(7) If pressure exceeds maximum limits, inspect
exhaust system for restricted component. For further
catalytic converter inspection procedures, (Refer to 11
- EXHAUST SYSTEM/CATALYTIC CONVERTER -
INSPECTION). Replace component(s) as necessary.
EXHAUST BACK PRESSURE LIMITS
Exhaust Back Pressure Limit (Max)
Vehicle in Park/Neutral
(no load) @2000 RPM3.45 Kpa (0.5 psi)
INSPECTION
Inspect the exhaust pipes, catalytic converters,
muffler, and resonators for cracked joints, broken
welds and corrosion damage that would result in a
leaking exhaust system. Inspect the clamps, support
brackets, and insulators for cracks and corrosion
damage.
NOTE: Slip joint band clamps are spot welded to
exhaust system. If a band clamp must be replaced,
the spot weld must be ground off.
ADJUSTMENTS
A misaligned exhaust system is usually indicated
by a vibration, rattling noise, or binding of exhaust
system components. These noises are sometimes hard
to distinguish from other chassis noises. Inspect
exhaust system for broken, damaged or loose compo-
nents such as; clamps, heat shields, isolators, and
hanger brackets. Replace or tighten as necessary. It
is important that exhaust system clearances and
alignment be maintained.
Perform the following procedures to align the
exhaust system:
(1) Loosen band clamp at catalytic converter pipe
to muffler/resonator assembly.
(2) Align the exhaust system by inserting pipe
inward or outward until specification is achieved as
shown in (Fig. 2).
(3) Tighten band clamp to 54 N´m (40 ft. lbs.).
SPECIFICATIONS
TORQUE
DESCRIPTION N´m Ft.
Lbs.In.
Lbs.
Band Clamp 54 40 Ð
Cross-over PipeÐFastener 41 30 Ð
Exhaust Manifold FlangeÐFastener 37 Ð 325
Heat Shield (Muffler)ÐFastener 2.6 Ð 23
Heat Shield (Toe Board)ÐFastener 2.6 Ð 23
Heat Shield (Resonator Pipe)Ð
Fastener2.6 Ð 23
Insulator Mounting BracketÐBolts 28 Ð 250
Fig. 2 Exhaust System Alignment
1 - HANGER BRACKET TO BODY
2 - ISOLATOR
3 - HANGER - MUFFLER/RESONATOR SUPPORT
4-6mm(0.25 in.)
RSEXHAUST SYSTEM11-3
EXHAUST SYSTEM (Continued)
INSPECTION
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER ATTEMPT TO SERVICE ANY
PART OF THE EXHAUST SYSTEM UNTIL IT IS
COOLED. SPECIAL CARE SHOULD BE TAKEN
WHEN WORKING NEAR THE CATALYTIC CON-
VERTER. THE TEMPERATURE OF THE CONVERTER
RISES TO A HIGH LEVEL AFTER A SHORT PERIOD
OF ENGINE OPERATION TIME.
Check catalytic converter for a flow restriction.
(Refer to 11 - EXHAUST SYSTEM - DIAGNOSIS
AND TESTING) Exhaust System Restriction Check
for procedure.
Visually inspect the catalytic converter element by
using a borescope or equivalent. Remove oxygen sen-
sor(s) and insert borescope. If borescope is not avail-
able, remove converter and inspect element using a
flashlight. Inspect element for cracked or melted sub-
strate.
NOTE: Before replacing a catalytic converter, deter-
mine the root cause of failure. Most catalytic con-
verter failures are caused by air, fuel or ignition
problems. (Refer to Appropriate Diagnostic Informa-
tion) for test procedures.
INSTALLATION
(1) Position new gasket onto the manifold flange
and install catalytic converter (Fig. 5). Tighten fas-
teners to 37 N´m (325 in. lbs.).
NOTE: Be careful not to twist or kink the oxygen
sensor wires.
(2) Install (if removed) and connect the down-
stream oxygen sensor (Fig. 4).
(3) Install the muffler/resonator assembly. (Refer
to 11 - EXHAUST SYSTEM/MUFFLER - INSTALLA-
TION)
(4) Start the engine and inspect for exhaust leaks.
Repair exhaust leaks as necessary.
(5) Check the exhaust system for contact with the
body panels. Make the necessary adjustments, if
needed.
CROSS-OVER PIPE - 3.3/3.8L
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the fasteners attaching the left bank
manifold connection to cross-over pipe (Fig. 6).
(3) Raise vehicle and remove the left front wheel.(4) Access the lower right bank pipe connection
fastener through the left front wheel opening using a
long ratchet extension. Loosen and remove the lower
fastener.
(5) Remove the upper right bank pipe connection
fastener by accessing though the catalytic converter
floor pan tunnel.
(6) Lower the vehicle.
(7) Remove the cross-over pipe (Fig. 6).
(8) Remove gaskets and discard (Fig. 6).
INSTALLATION
(1) Position cross-over pipe to the manifold connec-
tions (Fig. 6).
(2) Position new gasket on left bank (front) pipe
connection and loosely install fasteners (Fig. 6).
(3) Raise the vehicle.
(4) Position new gasket on the right bank pipe con-
nection and install fasteners.
(5) Tighten right bank upper fastener to 41 N´m
(30 ft. lbs.).
(6) Tighten right bank lower fastener to 41 N´m
(30 ft. lbs.) using a long ratchet extension accessing
through the left wheel opening.
(7) Install the left front wheel and lower vehicle.
(8) Tighten the left bank pipe connection fasteners
to 41 N´m (30 ft. lbs.) (Fig. 6).
(9) Start the engine and inspect for exhaust leaks.
Repair exhaust leaks as necessary.
(10) Check the exhaust system for contact with the
body panels. Make the necessary adjustments, if
needed.
Fig. 6 CROSS-OVER PIPE
1 - CROSS-OVER PIPE
2 - BOLT
3 - GASKET
4 - FLAG NUT
11 - 6 EXHAUST SYSTEMRS
CATALYTIC CONVERTER (Continued)
HEAT SHIELDS
DESCRIPTION
The exhaust system heat shields (Fig. 7), (Fig. 8),
or (Fig. 9) are attached to the under body of the vehi-
cle. On vehicles equipped with All Wheel Dive
(AWD), an additional heat shield is mounted to the
catalytic converter.
OPERATION
Heat shields are needed to protect both the vehicle
and the environment from the high temperatures
developed near the catalytic converter.Avoid application of rust prevention com-
pounds or undercoating materials to exhaust
system floor pan heat shields on cars so
equipped. Light over spray near the edges is
permitted. Application of coating will greatly
reduce the efficiency of the heat shields result-
ing in excessive floor pan temperatures and
objectionable fumes.
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove fasteners attaching applicable heat
shield (Fig. 7), (Fig. 8), or (Fig. 9).
(3) Remove heat shield(s).
INSTALLATION
(1) Position heat shield(s) to underbody.
(2) Install heat shield fasteners and tighten to 2.6
N´m (23 in. lbs.) (Fig. 7), (Fig. 8), or (Fig. 9).
(3) Lower vehicle.
(4) Start the engine and inspect for exhaust leaks.
Repair exhaust leaks as necessary.
(5) Check the exhaust system for contact with the
body panels. Make the necessary adjustments, if
needed.
MUFFLER
REMOVAL
(1) Raise vehicle on a body contact type hoist.
NOTE: To provide removal clearance between muf-
fler/resonator pipe and rear axle parts, the rear sus-
pension must be relieved of all body weight.
(2) Apply a penetrating oil to clamp nuts of com-
ponent requiring removal.
Fig. 7 CATALYTIC CONVERTER HEAT SHIELD
1 - HEAT SHIELD - CATALYTIC CONVERTER
2 - SCREW (QTY. 4)
Fig. 8 MUFFLER HEAT SHIELD
1 - HEAT SHIELD - MUFFLER
2 - SCREW (QTY. 6)
Fig. 9 RESONATOR PIPE HEAT SHIELD
1 - SCREW (QTY. 3)
2 - HEAT SHIELD - RESONATOR PIPE
3 - MUFFLER
RSEXHAUST SYSTEM11-7