
Connector Name/Number Color Location Fig.
G100 Left Fender Side Shield 16
G101 Left Fender Side Shield 16
G102 Left Fender Side Shield (RWAL
Ground)N/S
G103 Near T/O for Wiper Motor 14
G105 Front of Engine (Engine Ground) 4,5,6,9
G107 (Diesel) Left Rear of Engine 10
G113 (Diesel) Primary Battery Engine Ground N/S
G114 Battery Engine Ground N/S
G115 (Diesel) Primary Battery Body Ground N/S
G116 Battery Frame Ground N/S
G117 (Diesel) Auxilary Battery Engine Ground N/S
G118 (Diesel) Primary Frame Ground N/S
G120 (Diesel) Auxilary Battery Body Ground N/S
G200 Left Cowl 24
G201 Instrument Panel Right Center
Support23,25
G300 Left Lower Cowl 20
G301 Below Left Rear Speaker 18
G302 At Overhead Console 20
Generator BK Front of Engine 7,8
Glove Box Lamp At Glove Box 23
Headlamp Switch C1 BK Left Side of Instrument Panel 23,26
Headlamp Switch C2 Left Side of Instrument Panel 23,26
Heated Mirror Switch Center of Instrument Panel 25
High Note Horn BK Front Bumper Right Support 17
Idle Air Control Motor BK On Throttle Body 9
Ignition Coil GY Right Front of Engine 4,5,9
Ignition Coil 4 Pack BK Right Side of Engine 9
Ignition Coil 6 Pack BK Right Side of Engine 9
Ignition Switch C1 Steering Column 24
Ignition Switch C2 Steering Column 24
Instrument Cluster C1 Rear of Instrument Cluster 23
Instrument Cluster C2 Rear of Instrument Cluster 23
Intake Air Heater Relay Left Fender Side Shield 16
Intake Air Temperature Sensor (Diesel) Left Rear of Engine 10
Intake Air Temperature Sensor (Gas) GY On Intake Manifold 4,5,6
Joint Connector No. 1 In Power Distribution Center N/S
Joint Connector No. 2 In Power Distribution Center N/S
Joint Connector No. 3 Front Bumper Right support 17
Joint Connector No. 4 Left Front Engine Compartment 16
Joint Connector No. 5 NAT Left Side of Instrument Panel 24
Joint Connector No. 6 NAT Left Side of Instrument Pane 24
8W - 90 - 4 8W-90 CONNECTOR/GROUND LOCATIONSBR/BE
CONNECTOR/GROUND LOCATIONS (Continued)

Connector Name/Number Color Location Fig.
Joint Connector No. 7 NAT Left Side of Instrument Pane 24
Joint Connector No. 8 NAT Center of Instrument Panel 23
Junction Block C1 BL Left Cowl 27
Junction Block C2 NAT Left Cowl 27
Junction Block C3 Left Cowl 20
Junction Block C4 BR Left Cowl 25
Junction Block C5 GN Left Cowl 25
Junction Block C6 BK Left Cowl 25
Junction Block C7 LTGY Left Cowl 25
Junction Block C8 OR Left Cowl 25
Junction Block C9 NAT Left Cowl 25
Leak Detection Pump BK Right Fender Side Shield 17
Left Back-Up Lamp GY Rear of Lamp N/S
Left Fog Lamp BK Rear of Fog Lamp N/S
Left Front Door Speaker (Premium) BK In Door 19
Left Front Door Speaker (Standard) BK In Door 19
Left Front Fender Lamp On Fender 21
Left Front Wheel Speed Sensor BK Left Fender Side Shield 14
Left Headlamp BK At Headlamp N/S
Left License Lamp BK At Rear Bumper 21
Left Outboard Clearance Lamp BK Behind Front of Headliner 20
Left Outboard Headlamp BL At Headlamp N/S
Left Outboard Identification Lamp BK Behind Front of Headliner 20
Left Park/Turn Signal Lamp BK At Lamp N/S
Left Power Mirror BK In Door 19
Left Rear Fender Lamp BK On Fender 21
Left Rear Speaker (Premium) At B Pillar 18
Left Rear Speaker (Standard) At B Pillar 18
Left Rear Door Speaker In Door 18
Left Remote Radio Switch Steering Wheel N/S
Left Speed Control Switch Steering Wheel N/S
Left Tail/Stop Turn Signal Lamp BK At Rear Bumper 21
Left Tweeter Left A Pillar N/S
Left Visor/Vanity Lamp BK Left A-Pillar 20
Low Note Horn BK Front Bumper Right Support 17
Manifold Absolute Pressure Sensor (V6, V8) BK On Throttle Body 4,5
Manifold Absolute Pressure Sensor (V10) BK Top of Intake Manifold 9
Manifold Air Pressure Sensor (Diesel) BK Rear of Intake Manifold 10
Multi-Function Switch On Steering Column 24
Output Speed Sensor BK Left Side of Transmission 13
Overdrive Switch On Shift Lever Arm N/S
Overhead Console BK Front of Headliner 20
BR/BE8W-90 CONNECTOR/GROUND LOCATIONS 8W - 90 - 5
CONNECTOR/GROUND LOCATIONS (Continued)

INSTALLATION...........................34
CRANKSHAFT OIL SEAL - REAR
DESCRIPTION...........................34
OPERATION.............................34
REMOVAL..............................35
INSTALLATION...........................35
DISTRIBUTOR BUSHING
REMOVAL..............................37
INSTALLATION...........................37
HYDRAULIC LIFTERS (CAM IN BLOCK)
DIAGNOSIS AND TESTING.................38
HYDRAULIC TAPPETS...................38
REMOVAL..............................39
CLEANING..............................39
INSTALLATION...........................39
PISTON & CONNECTING ROD
DESCRIPTION...........................40
STANDARD PROCEDURE..................40
PISTON FITTING.......................40
REMOVAL..............................40
CLEANING..............................41
INSPECTION............................41
INSTALLATION...........................41
PISTON RINGS
STANDARD PROCEDURE..................41
PISTON RING FITTING..................41
VIBRATION DAMPER
REMOVAL..............................42
INSTALLATION...........................42
FRONT MOUNT
REMOVAL..............................43
INSTALLATION...........................43
REAR MOUNT
REMOVAL..............................44
INSTALLATION...........................44
LUBRICATION
DESCRIPTION...........................45
OPERATION.............................45
DIAGNOSIS AND TESTING.................47
ENGINE OIL PRESSURE.................47
ENGINE OIL LEAKS.....................47
OIL
STANDARD PROCEDURE..................47
ENGINE OIL...........................47OIL FILTER
REMOVAL..............................48
INSTALLATION...........................48
OIL PAN
REMOVAL..............................48
CLEANING..............................49
INSPECTION............................49
INSTALLATION...........................49
OIL PRESSURE SENSOR/SWITCH
DESCRIPTION...........................49
OPERATION.............................49
OIL PUMP
REMOVAL..............................50
DISASSEMBLY...........................50
CLEANING..............................50
INSPECTION............................50
ASSEMBLY.............................51
INSTALLATION...........................52
INTAKE MANIFOLD
DESCRIPTION...........................52
OPERATION.............................52
DIAGNOSIS AND TESTING.................53
INTAKE MANIFOLD LEAKAGE.............53
REMOVAL..............................53
CLEANING..............................53
INSPECTION............................53
INSTALLATION...........................53
EXHAUST MANIFOLD
DESCRIPTION...........................55
OPERATION.............................55
REMOVAL..............................55
CLEANING..............................55
INSPECTION............................55
INSTALLATION...........................55
TIMING BELT / CHAIN COVER(S)
REMOVAL..............................56
INSTALLATION...........................56
TIMING BELT/CHAIN TENSIONER
DESCRIPTION...........................57
OPERATION.............................57
TIMING BELT/CHAIN AND SPROCKETS
REMOVAL..............................57
INSPECTION............................58
INSTALLATION...........................58
9 - 2 ENGINE 3.9LBR/BE

ENGINE 3.9L
DESCRIPTION
The 3.9 Liter (238 CID) six-cylinder engine is a
V-Type, lightweight, single cam, overhead valve
engine with hydraulic roller tappets. This engine is
designed to use unleaded fuel.
The engine lubrication system consists of a rotor
type oil pump and a full-flow oil filter.
The cylinders are numbered from front to rear; 1,
3, 5 on the left bank and 2, 4, 6 on the right bank.
The firing order is 1-6-5-4-3-2 (Fig. 1).
The engine serial number is stamped into a
machined pad located on the left front corner of the
cylinder block. When component part replacement is
necessary, use the engine type and serial number for
reference (Fig. 2).
DIAGNOSIS AND TESTINGÐENGINE
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 9 - ENGINE - DIAGNOSIS AND TEST-
ING - Preformance) or (Refer to 9 - ENGINE - DIAG-
NOSIS AND TESTING - Mechanical). Refer to 14 -
FUEL SYSTEM for fuel system diagnosis.
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
²Cylinder Head Gasket Failure Diagnosis
²Intake Manifold Leakage Diagnosis
²Lash Adjuster (Tappet) Noise Diagnosis
²Engine Oil Leak Inspection
Fig. 1 Firing Order
Fig. 2 Engine Identification (Serial) Number
BR/BEENGINE 3.9L 9 - 3
ENGINE 3.9L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
11. Faulty ignition cables 11. Replace any cracked or shorted
cables
12. Faulty ignition coil 12. Test and replace, as necessary (Refer
to 8 - ELECTRICAL/IGNITION
CONTROL/IGNITION COIL - REMOVAL).
ENGINE STALLS OR
ROUGH IDLE1. Carbon build-up on throttle plate 1. Remove throttle body and de-carbon.
(Refer to 14 - FUEL SYSTEM/FUEL
INJECTION/THROTTLE BODY -
REMOVAL).
2. Engine idle speed too low 2. Check Idle Air Control circuit. (Refer to
14 - FUEL SYSTEM/FUEL INJECTION/
IDLE AIR CONTROL MOTOR -
DESCRIPTION)
3. Worn or incorrectly gapped spark
plugs3. Replace or clean and re-gap spark
plugs (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING)
4. Worn or burned distributor rotor 4. Install new distributor rotor
5. Spark plug cables defective or
crossed5. Check for correct firing order or
replace spark plug cables. (Refer to 8 -
ELECTRICAL/IGNITION CONTROL/
SPARK PLUG CABLE - DIAGNOSIS
AND TESTING)
6. Faulty coil 6. Test and replace, if necessary (Refer
to 8 - ELECTRICAL/IGNITION
CONTROL/IGNITION COIL - REMOVAL)
7. Intake manifold vacuum leak 7. Inspect intake manifold gasket and
vacuum hoses (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD -
DIAGNOSIS AND TESTING).
ENGINE MISSES ON
ACCELERATION1. Worn or incorrectly gapped spark
plugs1. Replace spark plugs or clean and set
gap. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING)
2. Spark plug cables defective or
crossed2. Replace or rewire secondary ignition
cables. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
CABLE - REMOVAL)
3. Dirt in fuel system 3. Clean fuel system
4. Burned, warped or pitted valves 4. Install new valves
5. Faulty coil 5. Test and replace as necessary (Refer
to 8 - ELECTRICAL/IGNITION
CONTROL/IGNITION COIL - REMOVAL)
BR/BEENGINE 3.9L 9 - 5
ENGINE 3.9L (Continued)

(4) A controlled hone motor speed between 200 and
300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50É to 60É
angle. Faster up and down strokes increase the cross-
hatch angle.
(5) After honing, it is necessary that the block be
cleaned to remove all traces of abrasive. Use a brush
to wash parts with a solution of hot water and deter-
gent. Dry parts thoroughly. Use a clean, white, lint-
free cloth to check that the bore is clean. Oil the
bores after cleaning to prevent rusting.
STANDARD PROCEDUREÐHYDROSTATIC
LOCK
CAUTION: DO NOT use the starter motor to rotate
the crankshaft. Severe damage could occur.
When an engine is suspected of hydrostatic lock
(regardless of what caused the problem), follow the
steps below.
(1) Perform the Fuel Pressure Release Procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(2) Disconnect the negative cable(s) from the bat-
tery.
(3) Inspect air cleaner, induction system, and
intake manifold to ensure system is dry and clear of
foreign material.
(4) Place a shop towel around the spark plugs to
catch any fluid that may possibly be under pressure
in the cylinder head. Remove the spark plugs.
(5) With all spark plugs removed, rotate the crank-
shaft using a breaker bar and socket.
(6) Identify the fluid in the cylinders (coolant, fuel,
oil, etc.).
(7) Be sure all fluid has been removed from the
cylinders.
(8) Repair engine or components as necessary to
prevent this problem from occurring again.
(9) Squirt a small amount of engine oil into the
cylinders to lubricate the walls. This will prevent
damage on restart.
(10) Install new spark plugs. Tighten the spark
plugs to 41 N´m (30 ft. lbs.) torque.
(11) Drain engine oil. Remove and discard the oil
filter.
(12) Install the drain plug. Tighten the plug to 34
N´m (25 ft. lbs.) torque.
(13) Install a new oil filter.
(14) Fill engine crankcase with the specified
amount and grade of oil. (Refer to LUBRICATION &
MAINTENANCE - SPECIFICATIONS).
(15) Connect the negative cable(s) to the battery.
(16) Start the engine and check for any leaks.
STANDARD PROCEDUREÐREPAIR DAMAGED
OR WORN THREADS
CAUTION: Be sure that the tapped holes maintain
the original center line.
Damaged or worn threads can be repaired. Essen-
tially, this repair consists of:
²Drilling out worn or damaged threads.
²Tapping the hole with a special Heli-Coil Tap, or
equivalent.
²Installing an insert into the tapped hole to bring
the hole back to its original thread size.
STANDARD PROCEDUREÐFORM-IN-PLACE
GASKETS & SEALERS
There are numerous places where form-in-place
gaskets are used on the engine. Care must be taken
when applying form-in-place gaskets to assure
obtaining the desired results.Do not use form-in-
place gasket material unless specified.Bead size,
continuity, and location are of great importance. Too
thin a bead can result in leakage while too much can
result in spill-over which can break off and obstruct
fluid feed lines. A continuous bead of the proper
width is essential to obtain a leak-free gasket.
There are numerous types of form-in-place gasket
materials that are used in the engine area. Mopart
Engine RTV GEN II, MopartATF-RTV, and Mopart
Gasket Maker gasket materials, each have different
properties and can not be used in place of the other.
MOPARtENGINE RTV GEN II
MopartEngine RTV GEN II is used to seal com-
ponents exposed to engine oil. This material is a spe-
cially designed black silicone rubber RTV that
retains adhesion and sealing properties when
exposed to engine oil. Moisture in the air causes the
material to cure. This material is available in three
ounce tubes and has a shelf life of one year. After one
year this material will not properly cure. Always
inspect the package for the expiration date before
use.
MOPARtATF RTV
MopartATF RTV is a specifically designed black
silicone rubber RTV that retains adhesion and seal-
ing properties to seal components exposed to auto-
matic transmission fluid, engine coolants, and
moisture. This material is available in three ounce
tubes and has a shelf life of one year. After one year
this material will not properly cure. Always inspect
the package for the expiration date before use.
MOPARtGASKET MAKER
MopartGasket Maker is an anaerobic type gasket
material. The material cures in the absence of air
when squeezed between two metallic surfaces. It will
not cure if left in the uncovered tube. The anaerobic
BR/BEENGINE 3.9L 9 - 11
ENGINE 3.9L (Continued)

material is for use between two machined surfaces.
Do not use on flexible metal flanges.
MOPARtGASKET SEALANT
MopartGasket Sealant is a slow drying, perma-
nently soft sealer. This material is recommended for
sealing threaded fittings and gaskets against leakage
of oil and coolant. Can be used on threaded and
machined parts under all temperatures. This mate-
rial is used on engines with multi-layer steel (MLS)
cylinder head gaskets. This material also will pre-
vent corrosion. MopartGasket Sealant is available in
a 13 oz. aerosol can or 4oz./16 oz. can w/applicator.
FORM-IN-PLACE GASKET AND SEALER
APPLICATION
Assembling parts using a form-in-place gasket
requires care but it's easier then using precut gas-
kets.
MopartGasket Maker material should be applied
sparingly 1 mm (0.040 in.) diameter or less of sealant
to one gasket surface. Be certain the material sur-
rounds each mounting hole. Excess material can eas-
ily be wiped off. Components should be torqued in
place within 15 minutes. The use of a locating dowel
is recommended during assembly to prevent smear-
ing material off the location.
MopartEngine RTV GEN II or ATF RTV gasket
material should be applied in a continuous bead
approximately 3 mm (0.120 in.) in diameter. All
mounting holes must be circled. For corner sealing, a
3.17 or 6.35 mm (1/8 or 1/4 in.) drop is placed in the
center of the gasket contact area. Uncured sealant
may be removed with a shop towel. Components
should be torqued in place while the sealant is still
wet to the touch (within 10 minutes). The usage of a
locating dowel is recommended during assembly to
prevent smearing material off the location.
MopartGasket Sealant in an aerosol can should be
applied using a thin, even coat sprayed completely
over both surfaces to be joined, and both sides of a
gasket. Then proceed with assembly. Material in a
can w/applicator can be brushed on evenly over the
sealing surfaces. Material in an aerosol can should be
used on engines with multi-layer steel gaskets.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove the upper crossmember and top core
support.
(4) Remove the transmission oil cooler (Refer to 7 -
COOLING/TRANSMISSION/TRANS COOLER -
REMOVAL).(5) Discharge the air conditioning system, if
equipped (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE).
(6) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(7) Remove the A/C compressor with the lines
attached. Set aside.
(8) If equipped, remove the condenser (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING/
A/C CONDENSER - REMOVAL).
(9) Remove the washer bottle.
(10) Remove the fan and fan shroud (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(11) Remove radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(12) Remove the generator with the wire connec-
tions (Refer to 8 - ELECTRICAL/CHARGING/GEN-
ERATOR - REMOVAL).
(13) Remove the air cleaner box.
(14) Disconnect the throttle linkage.
(15) Remove throttle body (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/THROTTLE BODY -
REMOVAL).
(16) Remove the intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL).
(17) Remove the distributor cap and wiring.
(18) Disconnect the heater hoses.
(19) Disconnect the power steering hoses, if
equipped.
(20) Perform the Fuel System Pressure release
procedure (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY - STANDARD PROCEDURE).Disconnect
the fuel supply line (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/QUICK CONNECT FITTING -
STANDARD PROCEDURE).
(21) On Manual Transmission vehicles, remove the
shift lever.
(22) Raise and support the vehicle on a hoist.
(23) Remove the drain plug and drain the engine
oil.
(24) Remove engine front mount through-bolt nuts.
(25)Automatic TransmissionRemove the trans-
mission cooler line brackets from oil pan.
(26) Disconnect exhaust pipe at manifold.
(27) Remove starter motor (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL).
(28)Manual TransmissionRemove the transmis-
sion.(Refer to 21 - TRANSMISSION/TRANSAXLE/
MANUAL - REMOVAL).
(29) Lower the vehicle.
CAUTION: DO NOT lift the engine by the intake
manifold.
(30) Install an engine lifting fixture.
9 - 12 ENGINE 3.9LBR/BE
ENGINE 3.9L (Continued)

(31) Remove engine from vehicle and install
engine assembly on a repair stand.
INSTALLATION
(1) Remove engine from the repair stand and posi-
tion in the engine compartment. Position the
through-bolt into the support cushion brackets.
(2) Install an engine support fixture.
(3) Raise and support the vehicle on a hoist.
(4)Manual TransmissionInstall the transmis-
sion (Refer to 21 - TRANSMISSION/TRANSAXLE/
MANUAL - INSTALLATION).
(5) Install the starter and connect the starter
wires (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - INSTALLATION).
(6) Install exhaust pipe to manifold.
(7)Automatic TransmissionInstall the trans-
mission cooler line brackets on oil pan.
(8) Install engine front mount through-bolt nuts.
Tighten the nuts.
(9) Install the drain plug and tighten to 34 N´m
(25 ft. lbs.) torque.
(10) Lower the vehicle.
(11) Remove engine-lifting fixture.
(12) On Manual Transmission vehicles, install the
shift lever.
(13) Connect the fuel supply line (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/QUICK CON-
NECT FITTING - STANDARD PROCEDURE).
(14) Connect the power steering hoses, if equipped.
(15) Connect the heater hoses.
(16) Install the distributor cap and wiring.
(17) Install the intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).(18) Using a new gasket, install throttle body
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
THROTTLE BODY - INSTALLATION).
(19) Connect the throttle linkage.
(20) Install the air cleaner box.
(21) Install the generator and wire connections
(Refer to 8 - ELECTRICAL/STARTING/STARTER
MOTOR - INSTALLATION).
(22) Install radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - INSTALLATION).
(23) Install the fan and fan shroud (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - INSTALLA-
TION).
(24) Install the washer bottle.
(25) If equipped, install the condenser (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING/
A/C CONDENSER - INSTALLATION).
(26) Install the A/C compressor with the lines
attached.
(27) Install accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(28) Evacuate and charge the air conditioning sys-
tem, if equipped (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE).
(29) Install the transmission oil cooler (Refer to 7 -
COOLING/TRANSMISSION/TRANS COOLER -
INSTALLATION).
(30) Install the upper crossmember and top core
support.
(31) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(32) Connect the negative cable to the battery.
(33) Start engine and check for leaks.
BR/BEENGINE 3.9L 9 - 13
ENGINE 3.9L (Continued)