2002 JEEP LIBERTY fuel cap

8W-30 FUEL/IGNITION SYSTEM
Component Page
A/C Compressor Clutch.............. 8Wa-30-34
A/C Compressor Clutch Relay..... 8Wa-30-34, 2, 3
A/C High Pressure Switch............ 8Wa-30-29
A/C Low Pressure Switch.......... 8Wa-30-8, 29
A/C Pressure Transducer....... 8Wa-30-11, 23, 12
Accelerator Pedal Position Sensor...... 8Wa-30-27
Auto Shut Down Relay . . 8Wa-30-13, 14, 15, 24, 28,
31, 16, 17, 2
Battery Temperature Sensor........ 8Wa-30-30, 7
Blower Motor Relay................. 8Wa-30-31
Body Control Module.............. 8Wa-30-8, 33
Boost Pressure Sensor............ 8Wa-30-26, 28
Brake Lamp Switch............ 8Wa-30-8, 32, 33
Cabin Heater...................... 8Wa-30-34
Cabin Heater Relay................. 8Wa-30-34
Camshaft Position Sensor....... 8Wa-30-10, 9, 28
Capacitor...................... 8Wa-30-19, 17
Clockspring..................... 8Wa-30-33, 7
Clutch Switch Override Relay.... 8Wa-30-13, 8, 32
Coil On Plug No. 1................. 8Wa-30-19
Coil On Plug No. 2................. 8Wa-30-20
Coil On Plug No. 3................. 8Wa-30-19
Coil On Plug No. 4................. 8Wa-30-20
Coil On Plug No. 5................. 8Wa-30-19
Coil On Plug No. 6................. 8Wa-30-20
Coil Rail......................... 8Wa-30-17
Controller Antilock Brake............ 8Wa-30-33
Crankshaft Position Sensor...... 8Wa-30-10, 9, 27
Data Link Connector.............. 8Wa-30-25, 6
Diagnostic Junction Port........... 8Wa-30-25, 6
EGR Solenoid..................... 8Wa-30-30
Engine Control Module . . 8Wa-30-24, 25, 26, 27, 28,
29, 30, 31, 32, 33, 34, 35, 36
Engine Coolant Temperature Sensor . 8Wa-30-11, 28,
12
Engine Oil Pressure Sensor..... 8Wa-30-11, 28, 12
Evap/Purge Solenoid................. 8Wa-30-2
Fuel Heater....................... 8Wa-30-31
Fuel Heater Relay.................. 8Wa-30-31
Fuel Injector No. 1............... 8Wa-30-18, 36
Fuel Injector No. 2............... 8Wa-30-18, 36
Fuel Injector No. 3............... 8Wa-30-18, 36
Fuel Injector No. 4............... 8Wa-30-18, 36
Fuel Injector No. 5................. 8Wa-30-18
Fuel Injector No. 6................. 8Wa-30-18
Fuel Pressure Sensor............... 8Wa-30-36
Fuel Pressure Solenoid.............. 8Wa-30-31
Fuel Pump Module............. 8Wa-30-30, 4, 5
Fuel Pump Relay.............. 8Wa-30-4, 2, 3, 5
Fuse 2........................... 8Wa-30-23
Fuse 6................... 8Wa-30-24, 28, 31, 2Component Page
Fuse 10.......................... 8Wa-30-35
Fuse 11.......................... 8Wa-30-35
Fuse 12....................... 8Wa-30-31, 33
Fuse 15...................... 8Wa-30-25, 2, 3
Fuse 16...... 8Wa-30-13, 14, 15, 24, 30, 34, 35, 16
Fuse 21.......................... 8Wa-30-34
Fuse 24...................... 8Wa-30-31, 2, 3
Fuse 26.................. 8Wa-30-18, 24, 17, 2
Fuse 28.......................... 8Wa-30-13
G100.................... 8Wa-30-19, 27, 17, 3
G101............................ 8Wa-30-23
G103................. 8Wa-30-15, 23, 31, 34, 16
G104............................ 8Wa-30-27
G111 ............................ 8Wa-30-31
G112 .......................... 8Wa-30-8, 23
G320........................... 8Wa-30-4, 5
Generator.................. 8Wa-30-24, 4, 3, 5
Glow Plug Assembly................ 8Wa-30-35
Glow Plug Relay No. 1.............. 8Wa-30-35
Glow Plug Relay No. 2.............. 8Wa-30-35
Idle Air Control Motor............ 8Wa-30-21, 22
Ignition Switch.................... 8Wa-30-32
Intake Air Temperature Sensor..... 8Wa-30-11, 12
Junction Block........... 8Wa-30-25, 31, 33, 2, 3
Knock Sensor...................... 8Wa-30-8
Leak Detection Pump.............. 8Wa-30-4, 5
Left Speed Control Switch.......... 8Wa-30-33, 7
Manifold Absolute Pressure Sensor . . 8Wa-30-11, 12
Oxygen Sensor 1/1 Upstream...... 8Wa-30-14, 15
Oxygen Sensor 1/2 Downstream . 8Wa-30-13, 14, 15
Oxygen Sensor 2/1 Upstream......... 8Wa-30-16
Oxygen Sensor 2/2 Downstream.... 8Wa-30-13, 16
Oxygen Sensor Downstream Relay . . 8Wa-30-13, 15,
16
Power Distribution Center . . 8Wa-30-13, 14, 15, 23,
24, 28, 30, 31, 34, 35, 16, 17, 2, 3
Power Steering Pressure Switch....... 8Wa-30-23
Powertrain Control Module . . . 8Wa-30-10, 13, 20, 8,
11, 14, 15, 18, 19, 21, 9, 23, 4, 12, 16, 17, 2, 22, 3,
6, 7, 5
Radiator Fan Motor................. 8Wa-30-23
Radiator Fan Relay................. 8Wa-30-23
Right Speed Control Switch......... 8Wa-30-33, 7
Shifter Assembly................. 8Wa-30-8, 32
Speed Control Servo................. 8Wa-30-8
Starter Motor Relay................ 8Wa-30-13
Throttle Position Sensor.......... 8Wa-30-21, 22
Transfer Case Position Sensor.... 8Wa-30-9, 23, 32
Transmission Control Module . . 8Wa-30-10, 8, 22, 6
Transmission Solenoid/Trs Assembly.... 8Wa-30-10
Water In Fuel Sensor............... 8Wa-30-29
KJ8W-30 FUEL/IGNITION SYSTEM8Wa-30-1

Component Page
C316 (Built-Up-Export).............. 8Wa-80-46
C316 (Built-Up-Export).............. 8Wa-80-46
C317 (Except Built-Up-Export)........ 8Wa-80-47
C317 (Except Built-Up-Export)........ 8Wa-80-47
Cabin Heater (Diesel)............... 8Wa-80-47
Camshaft Position Sensor (2.4L)....... 8Wa-80-47
Camshaft Position Sensor (3.7L)....... 8Wa-80-47
Camshaft Position Sensor (Diesel)...... 8Wa-80-48
Capacitor......................... 8Wa-80-48
Cargo Lamp (Except Base)........... 8Wa-80-48
CD Changer...................... 8Wa-80-48
Center High Mounted Stop Lamp...... 8Wa-80-49
Cigar Lighter..................... 8Wa-80-49
Clockspring C1.................... 8Wa-80-49
Clockspring C2.................... 8Wa-80-49
Clockspring C3.................... 8Wa-80-49
Clutch Interlock Switch (M/T)......... 8Wa-80-50
Coil On Plug No. 1 (3.7L)............ 8Wa-80-50
Coil On Plug No. 2 (3.7L)............ 8Wa-80-50
Coil On Plug No. 3 (3.7L)............ 8Wa-80-50
Coil On Plug No. 4 (3.7L)............ 8Wa-80-50
Coil On Plug No. 5 (3.7L)............ 8Wa-80-51
Coil On Plug No. 6 (3.7L)............ 8Wa-80-51
Coil Rail (2.4L).................... 8Wa-80-51
Compass Mini-Trip Computer
(Premium)...................... 8Wa-80-51
Controller Antilock Brake............ 8Wa-80-52
Crankshaft Position Sensor (2.4L)...... 8Wa-80-52
Crankshaft Position Sensor (3.7L)...... 8Wa-80-52
Crankshaft Position Sensor (Diesel).... 8Wa-80-53
Data Link Connector................ 8Wa-80-53
Diagnostic Junction Port............. 8Wa-80-53
Dome Lamp (Base)................. 8Wa-80-54
Driver Airbag Squib 1............... 8Wa-80-54
Driver Airbag Squib 2............... 8Wa-80-54
Driver Seat Belt Switch............. 8Wa-80-54
Driver Seat Belt Tensioner........... 8Wa-80-54
EGR Solenoid (Diesel)............... 8Wa-80-55
Engine Control Module C1........... 8Wa-80-55
Engine Control Module C2........... 8Wa-80-56
Engine Coolant Level Sensor (Diesel) . . . 8Wa-80-57
Engine Coolant Temp Sensor (Diesel) . . . 8Wa-80-57
Engine Coolant Temperature
Sensor (Gas).................... 8Wa-80-58
Engine Oil Pressure Sensor........... 8Wa-80-58
Evap/Purge Solenoid................ 8Wa-80-58
Flip-Up Glass Release Motor.......... 8Wa-80-58
Flip-Up Glass Release Switch......... 8Wa-80-58
Front Wiper Motor................. 8Wa-80-59
Fuel Heater (Diesel)................ 8Wa-80-59
Fuel Injector No. 1 (Diesel)........... 8Wa-80-59
Fuel Injector No. 1 (Gas)............. 8Wa-80-59
Fuel Injector No. 2 (Diesel)........... 8Wa-80-59
Fuel Injector No. 2 (Gas)............. 8Wa-80-60Component Page
Fuel Injector No. 3 (Diesel)........... 8Wa-80-60
Fuel Injector No. 3 (Gas)............. 8Wa-80-60
Fuel Injector No. 4 (Diesel)........... 8Wa-80-60
Fuel Injector No. 4 (Gas)............. 8Wa-80-60
Fuel Injector No. 5 (3.7L)............ 8Wa-80-61
Fuel Injector No. 6 (3.7L)............ 8Wa-80-61
Fuel Pressure Sensor (Diesel)......... 8Wa-80-61
Fuel Pressure Solenoid (Diesel)........ 8Wa-80-61
Fuel Pump Module................. 8Wa-80-61
G202............................ 8Wa-80-61
Generator........................ 8Wa-80-62
Glow Plug Assembly (Diesel).......... 8Wa-80-62
Hazard Switch/Combination Flasher.... 8Wa-80-62
Headlamp Leveling Switch
(Built-Up-Export)................ 8Wa-80-63
Heated Seat Module (Highline)........ 8Wa-80-63
High Note Horn.................... 8Wa-80-63
Hood Ajar Switch (Except Base)....... 8Wa-80-63
Idle Air Control Motor............... 8Wa-80-64
Ignition Switch.................... 8Wa-80-64
Input Speed Sensor (3.7L)............ 8Wa-80-64
Instrument Cluster................. 8Wa-80-64
Intake Air Temperature Sensor (Gas) . . . 8Wa-80-65
Intrusion Sensor (Built-Up-Export)..... 8Wa-80-65
Junction Block Body Control Module-JB . 8Wa-80-65
Junction Block C1.................. 8Wa-80-66
Junction Block C2.................. 8Wa-80-67
Junction Block C3.................. 8Wa-80-68
Knock Sensor (3.7L)................ 8Wa-80-69
Leak Detection Pump............... 8Wa-80-69
Left Courtesy Lamp................ 8Wa-80-69
Left Curtain Airbag................. 8Wa-80-69
Left Cylinder Lock Switch (Except Base) . 8Wa-80-69
Left Door Lock Switch (Except Base) . . . 8Wa-80-70
Left Fog Lamp..................... 8Wa-80-70
Left Front Door Ajar Switch (Base)..... 8Wa-80-70
Left Front Door Lock Motor/Ajar Switch
(Except Base)................... 8Wa-80-70
Left Front Door Speaker (Base)........ 8Wa-80-70
Left Front Door Speaker (Premium).... 8Wa-80-71
Left Front Impact Sensor............ 8Wa-80-71
Left Front Park/Turn Signal Lamp..... 8Wa-80-71
Left Front Power Window Motor
(Midline/Highline)................ 8Wa-80-71
Left Front Wheel Speed Sensor (ABS) . . . 8Wa-80-72
Left Headlamp (Built-Up-Export)...... 8Wa-80-72
Left Headlamp (Except Built-Up-Export) . 8Wa-80-72
Left Heated Seat Assembly (Highline) . . . 8Wa-80-72
Left Heated Seat Switch (Highline)..... 8Wa-80-72
Left Instrument Panel Speaker........ 8Wa-80-73
Left Leveling Motor (Built-Up-Export) . . 8Wa-80-73
Left Position Lamp (Built-Up-Export) . . . 8Wa-80-73
Left Power Mirror (Except Base)....... 8Wa-80-73
8Wa - 80 - 2 8W-80 CONNECTOR PIN-OUTSKJ

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
C302 (LHD) OR Right A-Pillar 34, 41, 42
C302 (RHD) OR Left A-Pillar 38, 41
C303 (LHD) OR Right A-Pillar 34, 41, 42
C303 (RHD) OR Left A-Pillar 38, 41
C304 DB Right Mid B-Pillar 34, 39
C305 DB Left Mid B-Pillar 35, 38
C306 (LHD) WT Left Lower B-Pillar 35, 43
C306 (RHD) WT Right Lower B-Pillar 39, 45
C307 (LHD) LG Left Lower B-Pillar 35, 38, 44
C308 LG Left Rear Quarter Panel 43
C309 DB Left Rear Quarter Panel 43, 46
C310 LG Right Rear Quarter Panel 44, 45, 47
C311 LG Left Front Seat 35, 38
C312 (Highline) LG Left Front Seat 35, 38
C313 LG Right Front Seat 36, 39, 40
C314 LG Right Front Seat 36, 39, 40
C315 (Midline/Highline) (LHD) LG Right Front Seat 34
C315 (Midline/Highline) (RHD) LG Left Front Seat 38
C317 (Except BUX) LG On Rear Bumper 45
Cabin Heater (Diesel) BK Right Front Side of Engine 21
Camshaft Position Sensor (2.4L) BK Top of Engine N/S
Camshaft Position Sensor (3.7L) LG Right Side of Engine 4
Camshaft Position Sensor (Diesel) Top of Engine 22
Capacitor (3.7L) BK Rear Side of Engine
Compartment9, 10
Capacitor (2.4L) BK Left Rear Side of Engine 11, 12
CD Changer GN At CD Changer N/S
Center High Mounted Stop Lamp WT At Lamp 46
Cigar Lighter RD Behind Cigar Lighter N/S
Clockspring C1 WT Behind Steering Wheel N/S
Clockspring C2 YL Behind Steering Wheel N/S
Clockspring C3 BK At Steering Wheel N/S
Clutch Interlock Switch (LHD) BK Left Rear Side of Engine
Compartment31
Clutch Interlock Switch (RHD) BK Right Rear Side of Engine
Compartment26
Coil On Plug No.1 (3.7L) BK Left Side of Engine Near
Fuel Injector No.11
Coil On Plug No.2 (3.7L) BK Right Side of Engine Near
Fuel Injector No.22
Coil On Plug No.3 (3.7L) BK Left Side of Engine Near
Fuel Injector No.31
Coil On Plug No.4 (3.7L) BK Right Side of Engine Near
Fuel Injector No.42
KJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION8Wa-91-3
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
OIL PUMPING AT RINGS; SPARK
PLUGS FOULING1. Worn or damaged rings. 1. Hone cylinder bores and replace
rings.
2. Carbon in oil ring slots. 2. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
3. Incorrect ring size installed. 3. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
4. Worn valve guides. 4. Ream guides and replace valves
(Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE).
5. Leaking valve guide seals. 5. Replace valve guide seals.
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disable the fuel system (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DESCRIPTION).
(5) Remove the ASD relay (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/AUTO SHUT DOWN
RELAY - REMOVAL).
(6) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(7) Record the compression pressure on the 3rd
revolution. Continue the test for the remaining cylin-
ders.
(8) (Refer to 9 - ENGINE - SPECIFICATIONS) for
the correct engine compression pressures.
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
(1) Check the coolant level and fill as required. DO
NOT install the radiator cap.
(2) Start and operate the engine until it attains
normal operating temperature, then turn the engine
OFF.
(3) Remove the spark plugs.
(4) Remove the oil filler cap.
(5) Remove the air cleaner.
(6) Calibrate the tester according to the manufac-
turer's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.
(7) Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
Set piston of cylinder to be tested at TDC compres-
sion,While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
Refer to CYLINDER COMBUSTION PRESSURE
LEAKAGE DIAGNOSIS CHART .
9 - 8 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)

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.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Raise the vehicle on a hoist.
(3) Disconnect the exhaust pipe at the left side
exhaust manifold.
(4) Drain the engine coolant. Refer to COOLING
SYSTEM.
(5) Lower the vehicle.
(6) Remove the intake manifold. Refer to proce-
dure in this section.
(7) Remove the cylinder head cover. Refer to proce-
dure in this section.
(8) Remove the fan shroud and fan blade assembly.
Refer to COOLING SYSTEM.
(9) Remove accessory drive belt. Refer to COOL-
ING SYSTEM.
(10) Remove the power steering pump and set
aside.
(11) Rotate the crankshaft until the damper timing
mark is aligned with TDC indicator mark (Fig. 4).
(12) Verify the V6 mark on the camshaft sprocket
is at the 12 o'clock position (Fig. 5). Rotate the crank-
shaft one turn if necessary.
(13) Remove the crankshaft damper. Refer to Pro-
cedure.
(14) Remove the timing chain cover. Refer to pro-
cedure.
Fig. 4 Engine Top Dead Center
1 - TIMING CHAIN COVER
2 - CRANKSHAFT TIMING MARKS
9 - 20 ENGINE - 3.7LKJ
CYLINDER HEAD - LEFT (Continued)

(9) Using Special Tool 8516 Valve Spring Compres-
sor, install the rocker arms and the hydraulic lash
adjusters.
(10) Install the cylinder head cover. Refer to Cylin-
der Head Cover in this Section.
CYLINDER HEAD - RIGHT
DESCRIPTION
DESCRIPTION - CYLINDER HEAD
The cylinder heads are made of an aluminum alloy.
The cylinder head features two valves per cylinder
with pressed in powdered metal valve guides. The
cylinder heads also provide enclosures for the timing
chain drain, necessitating unique left and right cylin-
der heads.
DESCRIPTION - VALVE GUIDES
The valve guides are made of powered metal and
are pressed into the cylinder head. The guides are
not replaceable or serviceable, and valve guide ream-
ing is not recommended. If the guides are worn
beyond acceptable limits, replace the cylinder heads.
DESCRIPTION
The valves are made of heat resistant steel and
have chrome plated stems to prevent scuffing. Each
valve is actuated by a roller rocker arm which pivots
on a stationary lash adjuster. All valves use three
bead lock keepers to retain the springs and promote
valve rotation.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - HYDRAULIC LASH
ADJUSTER
A tappet-like noise may be produced from several
items. Check the following items.
(1) Engine oil level too high or too low. This may
cause aerated oil to enter the adjusters and cause
them to be spongy.
(2) Insufficient running time after rebuilding cylin-
der head. Low speed running up to 1 hour may be
required.
(3) Turn engine off and let set for a few minutes
before restarting. Repeat this several times after
engine has reached normal operating temperature.
(4) Low oil pressure.
(5) The oil restrictor in cylinder head gasket or the
oil passage to the cylinder head is plugged with
debris.(6) Air ingested into oil due to broken or cracked
oil pump pick up.
(7) Worn valve guides.
(8) Rocker arm ears contacting valve spring
retainer.
(9) Rocker arm loose, adjuster stuck or at maxi-
mum extension and still leaves lash in the system.
(10) Oil leak or excessive cam bore wear in cylin-
der head.
(11) Faulty lash adjuster.
²Check lash adjusters for sponginess while
installed in cylinder head and cam on camshaft at
base circle. Depress part of rocker arm over adjuster.
Normal adjusters should feel very firm. Spongy
adjusters can be bottomed out easily.
²Remove suspected lash adjusters, and replace.
²Before installation, make sure adjusters are at
least partially full of oil. This can be verified by little
or no plunger travel when lash adjuster is depressed.
DIAGNOSIS AND TESTING - CYLINDER 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.
9 - 30 ENGINE - 3.7LKJ
VALVE SPRINGS (Continued)

DIAGNOSIS AND TESTING - REAR SEAL AREA
LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak:
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, camshaft bore
cup plugs, oil galley pipe plugs, oil filter runoff,
and main bearing cap to cylinder block mating sur-
faces. See Engine, for proper repair procedures of
these items.
(4) If no leaks are detected, pressurized the crank-
case as outlined in the section, Inspection (Engine oil
Leaks in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible the
crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks or
scratches. The crankshaft seal flange is specially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled. (Refer to 9 - ENGINE - DIAGNOSIS AND
TESTING), under the Oil Leak row, for components
inspections on possible causes and corrections.
(7) After the oil leak root cause and appropriate
corrective action have been identified, (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT OIL
SEAL - REAR - REMOVAL).
OIL
STANDARD PROCEDURE - ENGINE OIL
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY.
ENGINE OIL SPECIFICATION
CAUTION: Do not use non-detergent or straight
mineral oil when adding or changing crankcase
lubricant. Engine failure can result.
API SERVICE GRADE CERTIFIED
Use an engine oil that is API Service Grade Certi-
fied. MOPARtprovides engine oils that conform to
this service grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. Use only engine oils with multi-
Fig. 70 Oil Pressure Sending Unit -Typical
1 - BELT
2 - OIL PRESSURE SENSOR
3 - OIL FILTER
4 - ELEC. CONNECTOR
KJENGINE - 3.7L 9 - 61
LUBRICATION (Continued)

AIR CLEANER ELEMENT
REMOVAL - 2.4L
Housing removal is not necessary for element (fil-
ter) replacement.
(1) Disconnect air intake duct at side of element
cover.
(2) Pry up 2 spring clips from front of housing
cover (spring clips retain cover to housing).
(3) Release housing cover from locating tabs
located on rear of housing, and remove cover.
(4) Remove air cleaner element (filter) from hous-
ing.
(5) Clean inside of housing before replacing ele-
ment.
INSTALLATION - 2.4L
(1) Install element into housing.
(2) Position housing cover into housing locating
tabs.
(3) Pry up spring clips and lock cover to housing.
(4) Connect air intake duct.
If any air filter, air resonator, air intake tubes or
air filter housing clamps had been loosened or
removed, tighten them to 5 N´m (40 in. lbs.) torque.
CYLINDER HEAD
DESCRIPTION
The cross flow designed, aluminum cylinder head
contains dual over-head camshafts with four valves
per cylinder (Fig. 5). The valves are arrange in two
in-line banks. The intake valves face toward the left
side of the vehicle. The exhaust valves face the right
side. The cylinder head incorporates powdered metalvalve guides and seats. The cylinder head is sealed to
the block using a multi-layer steel head gasket and
retaining bolts.
Integral oil galleries providing lubrication passages
to the hydraulic lash adjusters, camshafts, and valve
mechanisms.
OPERATION
The cylinder head closes the combustion chamber,
allowing the pistons to compress the fuel/air mixture
for ignition. The valves are actuated by the lobe pro-
files on the camshaft to open and close at specified
duration to either allow clean air in the combustion
chamber or the exhaust gases out; depending on the
stroke of the engine.
DIAGNOSIS AND TESTING - CYLINDER 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
Combustion Leak Tester C-3685-A
Cylinder Compression Pressure Adaptor 8116
Fig. 5 Cylinder Head and Camshafts
CAM PLUG - NOT SHOWN
1 - CAMSHAFT BEARING CAPS
2 - PLUG
3 - CAMSHAFT
4 - CYLINDER HEAD
5 - CAMSHAFT OIL SEAL
KJENGINE9s-19
ENGINE - 2.4L (Continued)