INTAKE MANIFOLD - UPPER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect connector from inlet air tempera-
ture sensor (Fig. 104).
(3) Disconnect air intake tube at throttle body and
remove upper air cleaner housing.
(4) Disconnect connector from throttle position
sensor (TPS) (Fig. 106).
(5) Disconnect connector from idle air control (IAC)
motor (Fig. 106).
(6) Disconnect connector from MAP sensor (Fig.
105).
(7) Remove vacuum lines for purge solenoid and
PCV valve at intake manifold.(8) Remove vacuum lines for power brake booster,
LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at upper intake manifold fittings.
(9) Disconnect throttle, speed control (if equipped),
and transaxle control (31TH equipped only) cables
from throttle lever and bracket. (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/THROTTLE CONTROL
CABLE - REMOVAL)
(10) Remove the EGR tube. (Refer to 25 - EMIS-
SIONS CONTROL/EXHAUST GAS RECIRCULA-
TION/TUBE - REMOVAL)
(11) Remove the upper manifold support bracket
bolt to manifold (Fig. 107).
Fig. 104 INLET AIR TEMPERATURE SENSOR - 2.4L
Fig. 105 MAP SENSOR - 2.4L
Fig. 106 Throttle Body Electrical Connectors -
Typical
1 - IDLE AIR CONTROL MOTOR CONNECTOR
2 - TPS CONNECTOR
Fig. 107 Upper Intake Manifold Support Bracket
1 - NUT - BRACKET TO CYLINDER HEAD COVER
2 - BOLT - BRACKET TO UPPER INTAKE MANIFOLD
3 - UPPER INTAKE MANIFOLD SUPPORT BRACKET
9 - 60 ENGINE 2.4LRS
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(12) Remove engine oil dipstick from tube.
(13) Remove upper intake manifold bolts (Fig.
108). Remove upper intake manifold.
CAUTION: Cover intake manifold to prevent foreign
material from entering engine.
INSPECTION
(1) Check manifold surfaces for flatness with
straight edge. Surface must be flat within 0.15 mm
per 300 mm (0.006 in. per foot) of manifold length.
(2) Inspect manifold for cracks or distortion.
Replace manifold if necessary.
INSTALLATION
(1) Clean manifold sealing surfaces.
(2) Apply a 1.5 mm (0.060 in.) bead MopartGas-
ket Maker to the perimeter of the lower intake man-
ifold runner openings.
(3) Install upper intake manifold and tighten fas-
teners to 28 N´m (250 in. lbs.) in sequence shown in
(Fig. 108). Repeat this procedures until all fasteners
are at specified torque.
(4) Install engine oil dipstick.
(5) Install upper bolt in intake manifold to front
support bracket (Fig. 107). Torque to 28 N´m (250 in.
lbs.).
(6) Install EGR tube. (Refer to 25 - EMISSIONS
CONTROL/EXHAUST GAS RECIRCULATION/
TUBE - INSTALLATION)
(7) Install throttle cables in bracket.
(8) Connect throttle, speed control, (if equipped),
transaxle control (31TH equipped only) cables to
throttle lever.
(9) Connect vacuum lines for power brake booster,
LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at upper intake manifold fittings.
(10) Connect vacuum lines for purge solenoid and
PCV valve.(11) Connect electrical connectors for MAP sensor,
throttle position sensor (TPS), and idle air control
(IAC) motor.
(12) Install air cleaner upper housing and air
intake tube to throttle body.
(13) Connect inlet air temperature sensor connec-
tor (Fig. 104).
(14) Connect negative cable to battery.
INTAKE MANIFOLD - LOWER
REMOVAL
(1) Perform fuel system pressure release proce-
durebefore attempting any repairs.(Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - STANDARD
PROCEDURE)
(2) Remove upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL)
CAUTION: Cover intake manifold openings to pre-
vent foreign material from entering engine.
(3) Disconnect fuel line. (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE)
(4) Drain the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
(5) Remove heater supply and radiator upper
hoses at intake manifold.
(6) Disconnect coolant temperature sensor/fuel
injector wire harness connector.
(7) Remove lower intake manifold support bracket
upper bolts (Fig. 109).
(8) Loosen the lower intake manfold support
bracket lower bolt (Fig. 109).
(9) Disconnect fuel injector harness.
(10) Remove the bolts attaching the power steering
reservoir to manifold. Set reservoir aside.Do not
disconnect line from reservoir.
(11) Remove lower intake manifold fasteners (Fig.
110). Remove the manifold from engine.
(12) Inspect the manifold. (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - INSPECTION)
INSPECTION
(1) Check manifold surfaces for flatness with
straight edge. Surface must be flat within 0.15 mm
per 300 mm (0.006 in. per foot) of manifold length.
(2) Inspect manifold for cracks or distortion.
Replace manifold if necessary.
INSTALLATION
If the following items were removed, install and
torque to specifications:
²Fuel rail bolts - 22 N´m (200 in. lbs.)
Fig. 108 Upper Intake Manifold Tightening Sequence
- 2.4L
RSENGINE 2.4L9-61
INTAKE MANIFOLD - UPPER (Continued)
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²Coolant outlet connector bolts - 28 N´m (250 in.
lbs.)
²Coolant temperature sensor - 7 N´m (60 in. lbs.)
(1) Position a new gasket on cylinder head and
install lower manifold.
(2) Install and tighten intake manifold fasteners to
28 N´m (250 in. lbs.) in the sequence shown in (Fig.
110). Repeat procedure until all bolts are at specified
torque.
(3) Install lower intake manifold support bracket
bolts (Fig. 109) and tighten to:
²Bolts to intake 28 N´m (250 in. lbs.)
²Bolt to engine block 54 N´m (40 ft. lbs.)
(4) Position power steering reservoir on manifold
and install bolts.(5) Connect the fuel line. (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE)
(6) Connect coolant temperature sensor/fuel injec-
tor wiring harness electrical connector.
(7) Install the radiator upper and heater supply
hoses.
(8) Install the upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION)
(9) Fill the cooling system. (Refer to 7 - COOLING
- STANDARD PROCEDURE)
EXHAUST MANIFOLD
DESCRIPTION
The exhaust manifold is made of Hi-Silicone Moly
nodular cast iron for strength and high tempera-
tures. The manifold attaches to the cylinder head.
OPERATION
The exhaust manifold collects the exhaust gasses
exiting the combustion chambers. Then it channels
the exhaust gasses to the exhaust pipe attached to
the manifold.
REMOVAL
(1) Raise vehicle and disconnect exhaust pipe from
the exhaust manifold.
(2) Disconnect upstream oxygen sensor connector
at the rear of exhaust manifold.
(3) Remove the bolts attaching the manifold to the
cylinder head.
(4) Remove exhaust manifold.
(5) Inspect the manifold. (Refer to 9 - ENGINE/
MANIFOLDS/EXHAUST MANIFOLD - INSPEC-
TION)
CLEANING
(1) Discard gasket (if equipped) and clean all sur-
faces of manifold and cylinder head.
INSPECTION
(1) Inspect manifold gasket surfaces for flatness
with straight edge. Surface must be flat within 0.15
mm per 300 mm (0.006 in. per foot) of manifold
length.
(2) Inspect manifolds for cracks or distortion.
Replace manifold as necessary.
INSTALLATION
(1) Install exhaust manifold with a new gasket.
Tighten attaching nuts in the sequence shown in
(Fig. 111) to 19 N´m (170 in. lbs.).
Fig. 109 Lower Intake Manifold Support Bracket
1 - SUPPORT BRACKET
2 - BOLTS - UPPER TO MANIFOLD
3 - BOLT - LOWER TO ENGINE BLOCK
Fig. 110 Lower Intake Manifold Tightening Sequence
9 - 62 ENGINE 2.4LRS
INTAKE MANIFOLD - LOWER (Continued)
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(2) Attach exhaust pipe to exhaust manifold and
tighten fasteners to 37 N´m (27 ft. lbs.).
(3) Install and connect the oxygen sensor. (Refer to
14 - FUEL SYSTEM/FUEL INJECTION/O2 SENSOR
- COMPONENT LOCATION)
TIMING BELT COVER(S)
REMOVAL
FRONT COVER
(1) Remove crankshaft vibration damper. (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL)
(2) Remove generator drive belt tensioner assem-
bly. (Refer to 7 - COOLING/ACCESSORY DRIVE/
BELT TENSIONERS - REMOVAL)
(3) Remove timing belt front cover bolts (Fig. 112)
and remove covers.
REAR COVER
(1) Remove front covers.
(2) Remove engine mount bracket (Fig. 113).
(3) Remove timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(4) Hold camshaft sprocket with Special Tool 6847
while removing center bolt (Fig. 114).
(5) Remove timing belt idler pulley.
(6) Remove rear cover fasteners and remove cover
from engine (Fig. 115).
INSTALLATION
REAR COVER
(1) Install timing belt rear cover and bolts (Fig.
115).CAUTION: Do not use an impact wrench for tighten-
ing camshaft sprocket bolt. Damage to the timing
locating pin can occur. Hand tighten using a
wrench ONLY.
(2) Install camshaft sprockets. Hold sprockets with
Special Tool 6848 and tighten center bolt to 101 N´m
(75 ft. lbs.).
(3) Install timing belt idler pulley and tighten
mounting bolt to 61 N´m (45 ft. lbs.).
(4) Install timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
(5) Install engine mount bracket and tighten bolts
to 61 N´m (45 ft. lbs.) (Fig. 113).
(6) Install front covers.
FRONT COVER
(1) Install timing belt front covers (Fig. 112).
Tighten fasteners to 7 N´m (60 in. lbs.).
(2) Install generator drive belt tensioner. (Refer to
7 - COOLING/ACCESSORY DRIVE/BELT TEN-
SIONERS - INSTALLATION)
Fig. 111 Exhaust Manifold Tightening Sequence
Fig. 112 Timing Belt Front Covers
1 - BOLTS - UPPER FRONT COVER 7 N´m (60 in. lbs.)
2 - BOLTS - LOWER FRONT COVER 7 N´m (60 in. lbs.)
RSENGINE 2.4L9-63
EXHAUST MANIFOLD (Continued)
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DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either
mechanical (e.g., a strange noise), or performance
(e.g., engine idles rough and stalls).
Refer to the Engine Mechanical and the Engine
Performance diagnostic charts, for possible causes
and corrections of malfunctions (Refer to 9 - ENGINE
- DIAGNOSIS AND TESTING - MECHANICAL)
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING
- PERFORMANCE).
For fuel system diagnosis, (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DIAGNOSIS AND
TESTING).
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can-
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following:
²Cylinder Compression Pressure Test
²Cylinder Combustion Pressure Leakage Test
²Engine Cylinder Head Gasket Failure Diagnosis
²Intake Manifold Leakage Diagnosis
²Hydraulic Lash Adjuster Noise Diagnosis
²Engine Oil Leak Inspection
Fig. 1 3.3/3.8L V-6 Engines
Fig. 2 Engine Identification
RSENGINE 3.3/3.8L9-77
ENGINE 3.3/3.8L (Continued)
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DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery. 1. Test battery. Charge or replace
as necessary. (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM -
DIAGNOSIS AND TESTING)
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to terminals.
3. Faulty starter. 3. Test starting system. (Refer to 8 -
ELECTRICAL/STARTING -
DIAGNOSIS AND TESTING)
4. Faulty coil(s) or control unit. 4. Test and replace as needed.
(Refer to Appropriate Diagnostic
Information)
5. Incorrect spark plug gap. 5. Set gap. (Refer to 8 -
ELECTRICAL/IGNITION CONTROL
- SPECIFICATIONS)
6. Contamination in fuel system. 6. Clean system and replace fuel
filter.
7. Faulty fuel pump. 7. Test fuel pump and replace as
needed. (Refer to Appropriate
Diagnostic Information)
8. Incorrect engine timing. 8. Check for a skipped timing
belt/chain.
ENGINE STALLS OR IDLES
ROUGH1. Idle speed too low. 1. Test minimum air flow. (Refer to
Appropriate Diagnostic Information)
2. Incorrect fuel mixture. 2. (Refer to Appropriate Diagnostic
Information)
3. Intake manifold leakage. 3. Inspect intake manifold, manifold
gasket, and vacuum hoses.
4. Faulty ignition coil(s). 4. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
9 - 78 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)
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CONDITION POSSIBLE CAUSE CORRECTION
ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped plugs. 1. Clean plugs and set gap.
2. Contamination in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
4. Incorrect valve timing. 4. Correct valve timing.
5. Leaking cylinder head gasket. 5. Replace cylinder head gasket.
6. Low compression. 6. Test compression of each
cylinder.
7. Burned, warped, or pitted valves. 7. Replace valves.
8. Plugged or restricted exhaust
system.8. Perform exhaust restriction test.
(Refer to 11 - EXHAUST SYSTEM -
DIAGNOSIS AND TESTING) Install
new parts, as necessary.
9. Faulty ignition coil(s). 9. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
ENGINE MISSES ON
ACCELERATION1. Dirty or incorrectly gapped spark
plugs.1. Clean spark plugs and set gap.
2. Contamination in Fuel System. 2. Clean fuel system and replace
fuel filter.
3. Burned, warped, or pitted valves. 3. Replace valves.
4. Faulty ignition coil(s). 4. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
ENGINE MISSES AT HIGH SPEED 1. Dirty or incorrect spark plug gap. 1. Clean spark plugs and set gap.
2. Faulty ignition coil(s). 2. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
3. Dirty fuel injector(s). 3. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
4. Contamination in fuel system. 4. Clean system and replace fuel
filter.
RSENGINE 3.3/3.8L9-79
ENGINE 3.3/3.8L (Continued)
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STANDARD PROCEDURE - HYDROSTATIC
LOCKED ENGINE
When an engine is suspected to be hydrostatically
locked, regardless of what caused the problem, the
following steps should be used.
CAUTION: DO NOT use starter motor to rotate the
engine, severe damage may occur.
(1) Inspect air cleaner, induction system and
intake manifold to insure system is dry and clear of
foreign material.
(2) Remove negative battery cable.
(3) Place a shop towel around the spark plugs
when removing them from the engine. This will catch
any fluid that may possibly be in the cylinder under
pressure.
(4) With all spark plugs removed, rotate engine
crankshaft using a breaker bar and socket.
(5) Identify the fluid in the cylinder(s) (i.e., cool-
ant, fuel, oil or other).
(6) Make sure all fluid has been removed from the
cylinders. Inspect engine for damage (i.e., connecting
rods, pistons, valves, etc.)
(7) Repair engine or components as necessary to
prevent this problem from re-occurring.
CAUTION: Squirt approximately one teaspoon of oil
into the cylinders, rotate engine to lubricate the cyl-
inder walls to prevent damage on restart.
(8) Install new spark plugs.
(9) Drain engine oil and remove oil filter.
(10) Install a new oil filter.
(11) Fill engine with specified amount of approved
oil.
(12) Connect negative battery cable.
(13) Start engine and check for any leaks.
STANDARD PROCEDURE - REPAIR OF
DAMAGED OR WORN THREADS
Damaged or worn threads (excluding spark plug
and camshaft bearing cap attaching threads) can be
repaired. Essentially, this repair consists of drilling
out worn or damaged threads, tapping the hole with
a special Heli-Coil Tap, (or equivalent) and installing
an insert into the tapped hole. This brings the hole
back to its original thread size.CAUTION: Be sure that the tapped holes maintain
the original center line.
Heli-Coil tools and inserts are readily available
from automotive parts jobbers.
STANDARD PROCEDURE - ENGINE CORE AND
OIL GALLERY PLUGS
Using a blunt tool such as a drift and a hammer,
strike the bottom edge of the cup plug. With the cup
plug rotated, grasp firmly with pliers or other suit-
able tool and remove plug (Fig. 5).
CAUTION: Do not drive cup plug into the casting as
restricted cooling can result and cause serious
engine problems.
Thoroughly clean inside of cup plug hole in cylin-
der block or head. Be sure to remove old sealer.
Lightly coat inside of cup plug hole with Mopart
Stud and Bearing Mount. Make certain the new plug
is cleaned of all oil or grease. Using proper drive
plug, drive plug into hole so that the sharp edge of
the plug is at least 0.5 mm (0.020 in.) inside the
lead-in chamfer.
It is not necessary to wait for curing of the sealant.
The cooling system can be refilled and the vehicle
placed in service immediately.
Fig. 5 Core Hole Plug Removal
1 - CYLINDER BLOCK
2 - REMOVE PLUG WITH PLIERS
3 - STRIKE HERE WITH HAMMER
4 - DRIFT PUNCH
5 - CUP PLUG
9 - 86 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)
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