Crank DODGE RAM 1500 1998 2.G Repair Manual

8W-30 FUEL/IGNITION SYSTEM
Component Page
A/C Compressor Clutch Relay............ 8W-30-9, 58
A/C Pressure Transducer......... 8W-30-23, 28, 29, 45
Accelerator Pedal Position Sensor . . . 8W-30-29, 47, 64, 65
Adjustable Pedal Motor................. 8W-30-61
Adjustable Pedal Relay.................. 8W-30-61
Adjustable Pedal Switch................. 8W-30-61
Ambient Temperature Sensor............. 8W-30-30
Auto Shut Down Relay................... 8W-30-4
Battery............................ 8W-30-52
Battery Temperature Sensor............ 8W-30-12, 56
Brake Lamp Switch............. 8W-30-8, 36, 57, 63
Camshaft Position Sensor........ 8W-30-10, 29, 45, 46
Capacitor........................... 8W-30-13
Clockspring..................... 8W-30-8, 36, 59
Coil On Plug No. 1.................. 8W-30-14, 39
Coil On Plug No. 2.................. 8W-30-15, 37
Coil On Plug No. 3.................. 8W-30-14, 39
Coil On Plug No. 4.................. 8W-30-15, 37
Coil On Plug No. 5.................. 8W-30-16, 39
Coil On Plug No. 6.................. 8W-30-13, 37
Coil On Plug No. 7.................. 8W-30-16, 39
Coil On Plug No. 8.................. 8W-30-13, 37
Condenser Fan Relay.................... 8W-30-9
Controller Antilock Brake............ 8W-30-6, 11, 57
Crankshaft Position Sensor............ 8W-30-10, 46
Data Link Connector............... 8W-30-9, 22, 55
Data Link Connector-Engine.............. 8W-30-51
EGR Solenoid................... 8W-30-28, 29, 32
Electronic Throttle Control Module.......... 8W-30-35
Engine Control Module....... 8W-30-42, 43, 44, 45, 46,
47, 48, 49, 50, 51, 52, 53, 54,
55, 56, 57, 58, 59, 60, 62, 63, 64, 65
Engine Coolant Temperature Sensor.... 8W-30-23, 41, 47
Engine Oil Pressure Switch.......... 8W-30-2, 53, 56
EVAP/Purge Solenoid................... 8W-30-12
Front Control Module................... 8W-30-61
Fuel Control Actuator................... 8W-30-50
Fuel Heater......................... 8W-30-60
Fuel Heater Relay..................... 8W-30-60
Fuel Injector No. 1.................. 8W-30-14, 40
Fuel Injector No. 2.................. 8W-30-15, 38
Fuel Injector No. 3.................. 8W-30-14, 40
Fuel Injector No. 4.................. 8W-30-15, 38
Fuel Injector No. 5.................. 8W-30-14, 40
Fuel Injector No. 6.................. 8W-30-15, 38
Fuel Injector No. 7.................. 8W-30-16, 40
Fuel Injector No. 8.................. 8W-30-13, 38
Fuel Injector Pack No. 1................. 8W-30-42
Fuel Injector Pack No. 2............ 8W-30-42, 43, 44
Fuel Injector Pack No. 3................. 8W-30-44
Fuel Pump Module................... 8W-30-3, 58
Fuel Pump Motor...................... 8W-30-48
Fuel Pump Relay....................... 8W-30-3
Fuse 2.............................. 8W-30-4
Fuse 5........................... 8W-30-25, 62
Fuse 12............................ 8W-30-60
Fuse 17............................. 8W-30-3
Fuse 19............................ 8W-30-52
Fuse 23............................. 8W-30-2Component Page
Fuse 36.......................... 8W-30-54, 61
Fuse 40............................ 8W-30-61
Fuse 49............................. 8W-30-4
Fuse 50..................... 8W-30-2, 55, 58, 62
Fusible Link......................... 8W-30-52
G104........................ 8W-30-3, 8, 25, 60
G105............................ 8W-30-56, 58
G107........... 8W-30-2, 7, 15, 18, 19, 20, 21, 30, 32
G114 .............................. 8W-30-53
G120............................ 8W-30-51, 60
G201............................... 8W-30-6
G202.............................. 8W-30-61
Generator......................... 8W-30-7, 51
Idle Air Control Motor................... 8W-30-9
Ignition Switch..................... 8W-30-6, 22
Inlet Air Temperature Sensor............. 8W-30-49
Input Speed Sensor.................... 8W-30-24
Instrument Cluster.................... 8W-30-30
Intake Air Heater Relay No. 1............. 8W-30-56
Intake Air Heater Relay No. 2............. 8W-30-56
Intake Air Temperature Sensor.......... 8W-30-23, 41
Intake Air Temperature/Manifold Absolute
Pressure Sensor..................... 8W-30-50
Integrated Power Module.... 8W-30-2, 3, 4, 9, 25, 52, 54,
55, 58, 60, 61, 62, 64
Knock Sensor........................ 8W-30-31
Knock Sensor-Left..................... 8W-30-33
Knock Sensor-Right.................... 8W-30-33
Lift Pump Motor...................... 8W-30-51
Line Pressure Sensor................... 8W-30-17
Manifold Absolute Pressure Sensor..... 8W-30-23, 29, 41
Natural Vacuum Leak Detection Assembly..... 8W-30-7
Output Speed Sensor................. 8W-30-24, 62
Oxygen Sensor 1/1 Upstream........... 8W-30-20, 21
Oxygen Sensor 1/2 Downstream......... 8W-30-18, 19
Oxygen Sensor 2/1 Upstream........... 8W-30-20, 21
Oxygen Sensor 2/2 Downstream......... 8W-30-18, 19
Oxygen Sensor Downstream Relay........... 8W-30-4
Power Steering Pressure Switch............ 8W-30-7
Powertrain Control Module....... 8W-30-2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29, 30, 31, 32,
33, 35, 36, 37, 38, 39, 40, 41
PTCNo.1 ....................... 8W-30-3, 9, 58
Pto Switch........................... 8W-30-6
Speed Control Servo.................. 8W-30-8, 63
Speed Control Switch-Left............. 8W-30-36, 59
Speed Control Switch-Right............ 8W-30-36, 59
Starter Motor Relay.................. 8W-30-2, 64
Throttle Position Sensor................. 8W-30-17
Tow/Haul Overdrive Switch............. 8W-30-6, 64
Transmission Control Relay............ 8W-30-25, 62
Transmission Range Sensor............... 8W-30-64
Transmission Solenoid Assembly......... 8W-30-54, 62
Transmission Solenoid/TRS Assembly . 8W-30-5, 25, 26, 27
Vacuum Pump........................ 8W-30-58
Vistronic Fan Drive.................... 8W-30-54
Water In Fuel Sensor................ 8W-30-47, 48
DR8W-30 FUEL/IGNITION SYSTEM 8W - 30 - 1

Component Page
C315............................. 8W-80-39
C316 (Heated Seats)................. 8W-80-39
C316............................. 8W-80-40
C319............................. 8W-80-40
C319............................. 8W-80-40
C320............................. 8W-80-40
C320............................. 8W-80-41
C322 (Except Heated Seats)........... 8W-80-41
C322............................. 8W-80-41
C323 (Except Heated Seats)........... 8W-80-42
C323 (Except Heated Seats)........... 8W-80-42
C323 (Heated Seats)................. 8W-80-42
C323 (Heated Seats)................. 8W-80-43
C327 (Dual Rear Wheels)............. 8W-80-43
C327 (Dual Rear Wheels)............. 8W-80-43
C328 (Dual Rear Wheels)............. 8W-80-43
C328 (Dual Rear Wheels)............. 8W-80-44
Camshaft Position Sensor (NGC)....... 8W-80-44
Camshaft Position Sensor (Diesel)...... 8W-80-44
Capacitor (3.7L/4.7L)................ 8W-80-44
Center High Mounted Stop Lamp/cargo
Lamp.......................... 8W-80-45
Cigar Lighter Outlet................. 8W-80-45
Clearance Lamp No. 1 (Heavy Duty).... 8W-80-45
Clearance Lamp No. 2 (Heavy Duty).... 8W-80-45
Clearance Lamp No. 3 (Heavy Duty).... 8W-80-46
Clearance Lamp No. 4 (Heavy Duty).... 8W-80-46
Clearance Lamp No. 5 (Heavy Duty).... 8W-80-46
Clockspring C1..................... 8W-80-46
Clockspring C2..................... 8W-80-47
Clockspring C3..................... 8W-80-47
Clockspring C4..................... 8W-80-47
Clutch Interlock Brake Switch......... 8W-80-47
Coil On Plug No. 1 (3.7L/4.7L)......... 8W-80-47
Coil On Plug No. 1 (5.7L)............. 8W-80-48
Coil On Plug No. 2 (3.7L/4.7L)......... 8W-80-48
Coil On Plug No. 2 (5.7L)............. 8W-80-48
Coil On Plug No. 3 (3.7L/4.7L)......... 8W-80-48
Coil On Plug No. 3 (5.7L)............. 8W-80-49
Coil On Plug No. 4 (3.7L/4.7L)......... 8W-80-49
Coil On Plug No. 4 (5.7L)............. 8W-80-49
Coil On Plug No. 5 (3.7L/4.7L)......... 8W-80-49
Coil On Plug No. 5 (5.7L)............. 8W-80-50
Coil On Plug No. 6 (3.7L/4.7L)......... 8W-80-50
Coil On Plug No. 6 (5.7L)............. 8W-80-50
Coil On Plug No. 7 (4.7L)............. 8W-80-50
Coil On Plug No. 7 (5.7L)............. 8W-80-51
Coil On Plug No. 8 (4.7L)............. 8W-80-51
Coil On Plug No. 8 (5.7L)............. 8W-80-51
Compass/Mini-Trip Computer (Except
Base).......................... 8W-80-51
Condenser Fan (NGC)............... 8W-80-52
Controller Anitlock Brake C1.......... 8W-80-52
Controller Antilock Brake C2 (ABS)..... 8W-80-52Component Page
Crankshaft Position Sensor (3.7L)...... 8W-80-52
Crankshaft Position Sensor (4.7L)...... 8W-80-53
Crankshaft Position Sensor (5.7L)...... 8W-80-53
Crankshaft Position Sensor (Diesel)..... 8W-80-53
Cylinder Lock Switch-Driver (Premium) . . 8W-80-53
Data Link Connector................ 8W-80-53
Data Link Connector-Engine (Diesel).... 8W-80-54
Dome Lamp....................... 8W-80-54
Door Ajar Switch-Driver.............. 8W-80-54
Door Ajar Switch-Left Rear........... 8W-80-54
Door Ajar Switch-Passenger........... 8W-80-55
Door Ajar Switch-Right Rear.......... 8W-80-55
Door Lock Motor/Ajar Switch-Driver.... 8W-80-55
Door Lock Motor/Ajar Switch-Left Rear . . 8W-80-55
Door Lock Motor/Ajar Switch-Passenger . 8W-80-56
Door Lock Motor/Ajar Switch-Right Rear . 8W-80-56
Door Lock Switch-Passenger........... 8W-80-56
Driver Blend Door Actuator (Dual Zone) . 8W-80-56
Driver Door Module C1.............. 8W-80-57
Driver Door Module C2.............. 8W-80-57
EGR Solenoid (4.7L/5.7L)............. 8W-80-57
Electric Brake Provision.............. 8W-80-58
Electric Throttle Control Module....... 8W-80-58
Engine Control Module C1 (Diesel)..... 8W-80-58
Engine Control Module C2 (Diesel)..... 8W-80-60
Engine Coolant Temperature Sensor
(Diesel)......................... 8W-80-61
Engine Coolant Temperature Sensor
(Gas)........................... 8W-80-61
Engine Oil Pressure Switch........... 8W-80-61
EVAP/Purge Solenoid (NGC).......... 8W-80-61
Evaporator Temperature Sensor........ 8W-80-62
Fender Lamp-Front Left (Dual Rear
Wheels)......................... 8W-80-62
Fender Lamp-Front Right (Dual Rear
Wheels)......................... 8W-80-62
Fender Lamp-Rear Left (Dual Rear
Wheels)......................... 8W-80-62
Fender Lamp-Rear Right (Dual Rear
Wheels)......................... 8W-80-62
Fog Lamp-Left..................... 8W-80-63
Fog Lamp-Right.................... 8W-80-63
Fuel Control Actuator (Diesel)......... 8W-80-63
Fuel Heater (Diesel)................. 8W-80-63
Fuel Injector No. 1 (Gas)............. 8W-80-63
Fuel Injector No. 2 (Gas)............. 8W-80-64
Fuel Injector No. 3 (Gas)............. 8W-80-64
Fuel Injector No. 4 (Gas)............. 8W-80-64
Fuel Injector No. 5 (Gas)............. 8W-80-64
Fuel Injector No. 6 (Gas)............. 8W-80-65
Fuel Injector No. 7 (Gas)............. 8W-80-65
Fuel Injector No. 8 (Gas)............. 8W-80-65
Fuel Injector Pack No. 1 (Diesel)....... 8W-80-65
Fuel Injector Pack No. 2 (Diesel)....... 8W-80-66
Fuel Injector Pack No. 3 (Diesel)....... 8W-80-66
8W - 80 - 2 8W-80 CONNECTOR PIN-OUTSDR

CONDENSER FAN (NGC) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 Z823 16BK/DG GROUND
2 C123 16LB/WT CONDENSER FAN RELAY OUTPUT
CONTROLLER ANITLOCK BRAKE C1 - BLACK 14 WAY
CAV CIRCUIT FUNCTION
1 B4 20DG/GY REAR WHEEL SPEED SENSOR (+)
2 B222 20DG/WT (ETC) VEHICLE SPEED SIGNAL NO. 2
3 D25 20WT/VT PCI BUS
4 F500 20DG/PK FUSED IGNITION SWITCH OUTPUT (RUN)
5 B9 20DG/LG (ETC) LEFT FRONT WHEEL SPEED SENSOR (+)
6 Z107 12BK/DG GROUND
7 A111 14DG/RD FUSED B(+)
8 B3 20DG/YL REAR WHEEL SPEED SENSOR (-)
9 B29 20DG/WT BRAKE SWITCH SIGNAL
10 B8 20DG/TN (ETC) LEFT FRONT WHEEL SPEED SENSOR (-)
11 B20 20DG/OR BRAKE FLUID LEVEL SWITCH SENSE
12 B22 20DG/YL VEHICLE SPEED SIGNAL NO. 1
13 Z127 12BK/DG (ABS) GROUND
14 A111 14DG/RD (ABS) FUSED B(+)
CONTROLLER ANTILOCK BRAKE C2 (ABS) - BLACK 4 WAY
CAV CIRCUIT FUNCTION
1 B9 20DG/LG LEFT FRONT WHEEL SPEED SENSOR (+)
2 B8 20DG/TN LEFT FRONT WHEEL SPEED SENSOR (-)
3 B6 20DG/WT RIGHT FRONT WHEEL SPEED SENSOR (-)
4 B7 20DG/VT RIGHT FRONT WHEEL SPEED SENSOR (+)
CRANKSHAFT POSITION SENSOR (3.7L)-3WAY
CAV CIRCUIT FUNCTION
1 K24 20BR/LB CKP SIGNAL
2 K900 20DB/DG SENSOR GROUND
3 F855 20PK/YL 5 VOLT SUPPLY
8W - 80 - 52 8W-80 CONNECTOR PIN-OUTSDR

CRANKSHAFT POSITION SENSOR (4.7L)-3WAY
CAV CIRCUIT FUNCTION
1 K24 20BR/LB CKP SIGNAL
2 K900 20DB/DG SENSOR GROUND
3 F855 20PK/YL 5 VOLT SUPPLY
CRANKSHAFT POSITION SENSOR (5.7L)-3WAY
CAV CIRCUIT FUNCTION
1 F855 20PK/YL 5 VOLT SUPPLY
2 K900 20DB/DG SENSOR GROUND
3 K24 20BR/LB CKP SIGNAL
CRANKSHAFT POSITION SENSOR (DIESEL)-3WAY
CAV CIRCUIT FUNCTION
1 K853 18DB/BR 5 VOLT SUPPLY
2 K975 18BR/BK SENSOR GROUND
2 K975 18BR/OR SENSOR GROUND
3 K24 18BR/LB CKP SIGNAL
3 K24 18LB/BR CKP SIGNAL
CYLINDER LOCK SWITCH-DRIVER (PREMIUM)-2WAY
CAV CIRCUIT FUNCTION
1 G163 20VT/LB DRIVER CYLINDER LOCK SWITCH MUX
2 Z463 20BK/LB GROUND
DATA LINK CONNECTOR - BLACK 16 WAY
CAV CIRCUIT FUNCTION
1- -
2 D25 20WT/VT PCI BUS
3- -
4 Z11 18BK/LG GROUND
5 Z111 18BK/WT GROUND
6- -
7 D21 18WT/BR SCI TRANSMIT (PCM)
8- -
9 D16 18WT/OR SCI RECEIVE (TCM)
10 - -
11 - -
DR8W-80 CONNECTOR PIN-OUTS 8W - 80 - 53

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
C315 DK GY At Driver Seat N/S
C316 BK At Passenger Seat N/S
C317 BK At Passenger Seat N/S
C319 BK Bottom Left of Left Door N/S
C320 Right Rear Door 43
C322 DK GY Left Rear of Frame 44, 46
C323 BK Left Side of Instrument Panel N/S
C327 BK Right Rear Fender 50, 51
C328 BK Left Rear Fender 50, 51, 52
Camshaft Position Sensor GY Right Front Side of Engine 3, 9
Capacitor Left Rear of Engine Compartment 4
Center High Mounted Stop
Lamp/Cargo LampBK Rear of Cab 49
Cigar Lighter Outlet NAT Rear of Cigar Lighter 32, 35, 36
Clearance Lamp No. 1 BK Left Roof 48
Clearance Lamp No. 2 BK Left-Center Roof 48
Clearance Lamp No. 3 BK Center Roof 48
Clearance Lamp No. 4 BK Right-Center Roof 48
Clearance Lamp No. 5 BK Right Roof 48
Clockspring C1 BK Steering Column 31
Clockspring C2 YL Steering Column 31
Clockspring C3 BK Steering Column N/S
Clockspring C4 BK Steering Column N/S
Clutch Interlock Brake Switch BK At Clutch Pedal 22, 24
Coil On Plug No.1 BK Left Top Side of Intake Manifold 6
Coil On Plug No.2 BK Right Top Side of Intake Manifold 3
Coil On Plug No.3 BK Left Top Side of Intake Manifold 6
Coil On Plug No.4 BK Right Top Side of Intake Manifold 3
Coil On Plug No.5 BK Left Top Side of Intake Manifold 5, 6
Coil On Plug No.6 BK Right Top Side of Intake Manifold 3
Coil On Plug No.7 BK Left Top Side of Intake Manifold 6
Coil On Plug No.8 BK Right Top Side of Intake Manifold 3
Compass/Mini-Trip Computer BK In Overhead Console N/S
Condenser Fan BK Near Condenser 23, 24
Controller Anti-Lock Brake C1 BK Left Fender Side Shield 22, 24, 25
Controller Anti-Lock Brake C2
(ABS)BK Left Fender Side Shield 22, 25
Crankshaft Position Sensor BK Right Rear of Engine Block 3, 9
Cylinder Lock Switch-Driver
(Premium)BK In Left Front Door 41
Cylinder Lock Switch-Passenger
(Premium)LT GY In Right Front Door N/S
Data Link Connector BK Left Bottom of Instrument Panel 35, 38
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 3
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

REMOVAL.............................38
INSTALLATION.........................38
ENGINE BLOCK
DESCRIPTION.........................38
STANDARD PROCEDURE - CYLINDER BORE
HONING............................38
CLEANING............................39
INSPECTION..........................39
CRANKSHAFT
DESCRIPTION.........................40
REMOVAL.............................40
INSPECTION..........................41
INSTALLATION.........................42
CRANKSHAFT MAIN BEARINGS
STANDARD PROCEDURE
MAIN BEARING FITTING................44
CRANKSHAFT OIL SEAL - FRONT
REMOVAL.............................46
INSTALLATION.........................46
CRANKSHAFT OIL SEAL - REAR
REMOVAL.............................47
INSTALLATION.........................47
FLEX PLATE
REMOVAL.............................48
INSTALLATION.........................48
PISTON & CONNECTING ROD
DESCRIPTION.........................48
STANDARD PROCEDURE
CONNECTING ROD BEARING FITTING....49
STANDARD PROCEDURE - PISTON FITTING..51
REMOVAL.............................51
CLEANING............................52
INSPECTION..........................52
INSTALLATION.........................52
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING.............................53
VIBRATION DAMPER
REMOVAL.............................55
INSTALLATION.........................56
STRUCTURAL COVER
DESCRIPTION.........................57
OPERATION...........................57
REMOVAL.............................57
INSTALLATION.........................57
FRONT MOUNT
REMOVAL.............................58
INSTALLATION.........................59
REAR MOUNT
REMOVAL.............................61
INSTALLATION.........................61
LUBRICATION
DESCRIPTION.........................61
OPERATION...........................61
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE OIL
LEAK...............................64DIAGNOSIS AND TESTING - CHECKING
ENGINE OIL PRESSURE................65
DIAGNOSIS AND TESTING - REAR SEAL
AREA LEAKS.........................65
OIL PAN
DESCRIPTION.........................66
REMOVAL.............................66
CLEANING............................66
INSPECTION..........................66
INSTALLATION.........................66
OIL PRESSURE SENSOR/SWITCH
DESCRIPTION.........................67
OPERATION...........................67
REMOVAL.............................67
INSTALLATION.........................67
OIL PUMP
REMOVAL.............................67
DISASSEMBLY.........................68
INSPECTION..........................68
ASSEMBLY............................69
INSTALLATION.........................69
OIL FILTER
REMOVAL.............................70
INSTALLATION.........................70
OIL
STANDARD PROCEDURE - ENGINE OIL
SERVICE............................71
INTAKE MANIFOLD
DESCRIPTION.........................72
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKS.....................72
REMOVAL.............................73
INSTALLATION.........................73
EXHAUST MANIFOLD
DESCRIPTION.........................74
REMOVAL.............................74
INSTALLATION.........................74
VALVE TIMING
DESCRIPTION.........................76
OPERATION...........................76
STANDARD PROCEDURE
MEASURING TIMING CHAIN WEAR.......77
SERVICE PROCEDURE - TIMING
VERIFICATION........................77
BALANCE SHAFT
REMOVAL.............................80
INSTALLATION.........................80
IDLER SHAFT
REMOVAL.............................81
INSTALLATION.........................81
TIMING BELT / CHAIN COVER(S)
REMOVAL.............................81
INSTALLATION.........................81
TIMING BELT/CHAIN AND SPROCKETS
REMOVAL.............................83
INSPECTION..........................84
INSTALLATION.........................85
9 - 2 ENGINE - 3.7LDR

ENGINE - 3.7L
DESCRIPTION
The 3.7 liter (226 CID) six-cylinder engine is an
90É single overhead camshaft engine (Fig. 1). The
cast iron cylinder block is made up of two different
components; the first component is the cylinder bore
and upper block, the second component is the bed-
plate that comprises the lower portion of the cylinderblock and houses the lower half of the crankshaft
main bearings. The cylinders are numbered from
front to rear with the left bank being numbered 1,3,
and 5 and the right bank being numbered 2,4, and 6.
The firing order is 1±6±5±4±3±2. The engine serial
number is located at the right front side of the
engine block
Fig. 1 3.7 L ENGINE
DRENGINE - 3.7L 9 - 3

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 per-
formance (e.g., engine idles rough and stalls) or
mechanical (e.g., a strange noise).
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING) - PERFORMANCE and (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)ÐMECHANICAL for
possible causes and corrections of malfunctions.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
DIAGNOSIS AND TESTING) and (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION - DIAGNOSIS
AND TESTING) for the 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 diagnosis:
²Cylinder Compression Pressure Test (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).
²Cylinder Combustion Pressure Leakage Test
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING).
²Engine Cylinder Head Gasket Failure Diagnosis
(Refer to 9 - ENGINE/CYLINDER HEAD - DIAGNO-
SIS AND TESTING).
²Intake Manifold Leakage Diagnosis (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
DIAGNOSIS AND TESTING).
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
6. Incorrect right bank cam timing. 6. Refer to engine timing in this
section.
7. Dirt or water in fuel system. 7. Clean system and replace fuel
filter.
8.Faulty fuel pump, relay or wiring. 8.Repair or replace as necessary.
9. Faulty cam or crank sensor 9. Refer to Ignition system.
ENGINE STALLS OR ROUGH IDLE 1. Vacuum leak. 1. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
2. Faulty crank position sensor 2. Replace crank position sensor.
3. Faulty coil. 3. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
9 - 4 ENGINE - 3.7LDR
ENGINE - 3.7L (Continued)

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTIONS
NOISY VALVES 1. High or low oil level in
crankcase.1. (Refer to LUBRICATION &
MAINTENANCE -
SPECIFICATIONS)
2. Thin or diluted oil. 2. Change oil and filter.
3. Low oil pressure. 3. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
4. Dirt in lash adjusters. 4. Replace as necessary.
5. Worn rocker arms. 5. Replace as necessary.
6. Worn lash adjusters 6. Replace as necessary.
7. Worn valve guides. 7. (Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE)
8. Excessive runout of valve seats
on valve faces.8. (Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE)
CONNECTING ROD NOISE 1. Insufficient oil supply. 1. (Refer to LUBRICATION &
MAINTENANCE -
SPECIFICATIONS)
2. Low oil pressure. 2. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Connecting rod journal
out-of-round.5. Service or replace crankshaft.
6. Misaligned connecting rods. 6. Replace bent connecting rods.
MAIN BEARING NOISE 1. Insufficient oil supply. 1. (Refer to LUBRICATION &
MAINTENANCE -
SPECIFICATIONS)
2. Low oil pressure. 2. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Excessive end play. 5. Check thrust washers for wear.
6. Crankshaft journal out-of round. 6. Service or replace crankshaft.
7. Loose flywheel or torque
converter.7. Tighten to correct torque
9 - 6 ENGINE - 3.7LDR
ENGINE - 3.7L (Continued)

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - LUBRICATION
CONDITION POSSIBLE CAUSES CORRECTION
OIL LEAKS 1. Gaskets and O-Rings. 1.
(a) Misaligned or damaged. (a) Replace as necessary.
(b) Loose fasteners, broken or
porous metal parts.(b) Tighten fasteners, Repair or
replace metal parts.
2. Crankshaft rear seal 2. Replace as necessary (Refer to 9
- ENGINE/ENGINE BLOCK/
CRANKSHAFT OIL SEAL - REAR -
REMOVAL).
3. Crankshaft seal flange.
Scratched, nicked or grooved.3. Polish or replace crankshaft.
4. Oil pan flange cracked. 4. Replace oil pan (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN -
REMOVAL).
5. Timing chain cover seal,
damaged or misaligned.5. Replace seal (Refer to 9 -
ENGINE/ENGINE BLOCK/
CRANKSHAFT OIL SEAL - FRONT
- REMOVAL).
6. Scratched or damaged vibration
damper hub.6. Polish or replace damper.
OIL PRESSURE DROP 1. Low oil level. 1. Check and correct oil level.
2. Faulty oil pressure sending unit. 2. Replace sending unit (Refer to 9
- ENGINE/LUBRICATION/OIL
PRESSURE SENSOR/SWITCH -
REMOVAL).
3. Low oil pressure. 3. Check oil pump and bearing
clearance.
4. Clogged oil filter. 4. Replace oil filter (Refer to 9 -
ENGINE/LUBRICATION/OIL FILTER
- REMOVAL).
5. Worn oil pump. 5. Replace oil pump (Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP
- REMOVAL).
6. Thin or diluted oil. 6. Change oil and filter.
7. Excessive bearing clearance. 7. Replace as necessary.
8. Oil pump relief valve stuck. 8. Replace oil pump (Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP
- REMOVAL).
9. Oil pick up tube loose, damaged
or clogged.9. Replace as necessary.
DRENGINE - 3.7L 9 - 7
ENGINE - 3.7L (Continued)