2002 JEEP LIBERTY eco

(3) Install timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
NOTE: Target ring tab should provide posative
snap-on fit on the camshaft.
(4) Install exhaust camshaft target ring with the
wordFRONTfacing forward.
(5) Install exhaust camshaft sensor.
(6) Install camshaft sprockets. Hold each sprocket
with Special Tool 6847 and tighten center bolt to 101
N´m (75 ft. lbs.).
(7) Install timing belt and front covers. (Refer to 9
- ENGINE/VALVE TIMING/TIMING BELT/CHAINAND SPROCKETS - INSTALLATION) (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
CAMSHAFT(S)
DESCRIPTION
Both nodular iron camshafts have six bearing jour-
nal surfaces and two cam lobes per cylinder (Fig. 15).
Flanges at the rear journals control camshaft end
play. Provision for a cam position sensor is located on
the exhaust camshaft on the front of the cylinder
head. A hydrodynamic oil seal is used for oil control
at the front of the camshaft.
OPERATION
The camshaft is driven by the crankshaft via drive
sprockets and belt. The camshaft has precisely
machined lobes to provide accurate valve timing and
duration.
STANDARD PROCEDURE - CAMSHAFT
END-PLAY
(1) Oil camshaft journals and install camshaft
WITHOUTcam follower assemblies. Install rear cam
caps and tighten screws to specified torque.
(2) Using a suitable tool, move camshaft as far
rearward as it will go.
(3) Zero dial indicator (Fig. 16).
(4) Move camshaft as far forward as it will go.
(5) Record reading on dial indicator. For end play
specification, (Refer to 9 - ENGINE - SPECIFICA-
TIONS).
(6) If end play is excessive, check cylinder head
and camshaft for wear; replace as necessary.
Fig. 12 Camshaft Sprocket - Removal/Installation
1 - SPECIAL TOOL 6847
Fig. 13 Camshaft Oil Seal - Removal With C-4679-A
1 - SPECIAL TOOL C-4679
Fig. 14 Camshaft Seal - Installation
1 - SPECIAL TOOL MD 998306
KJENGINE9s-23
CAMSHAFT OIL SEAL(S) (Continued)

INSPECTION
(1) Whenever valves have been removed for inspec-
tion, reconditioning or replacement, valve springs
should be tested for correct tension. Discard the
springs that do not meet specifications. The following
specifications apply to both intake and exhaust
valves springs:
²Valve Closed Nominal TensionÐ76 lbs. @ 38.0
mm (1.50 in.)
²Valve Open Nominal TensionÐ136 lbs. @ 29.75
mm (1.17 in.)
(2) Inspect each valve spring for squareness with a
steel square and surface plate, test springs from both
ends. If the spring is more than 1.5 mm (1/16 inch)
out of square, install a new spring.
INSTALLATION
INSTALLATION - CYLINDER HEAD ON
(1) Install valve seal/valve spring seat assembly
(Fig. 27). Push the assembly down to seat it onto the
valve guide.
(2) Install valve spring and retainer, use Special
Tool MD-998772-A with adapter 6779 to compress
valve springs only enough to install locks. Correct
alignment of tool is necessary to avoid nicking valve
stems.
(3) Remove air hose and install spark plugs.
(4) Install camshafts and cylinder head cover .
INSTALLATION - CYLINDER HEAD OFF
(1) Coat valve stems with clean engine oil and
insert in cylinder head.(2) Install new valve stem seals on all valves
using a valve stem seal tool (Fig. 28). The valve stem
seals should be pushed firmly and squarely over
valve guide.
CAUTION: When oversize valves are used, the cor-
responding oversize valve seal must also be used.
Excessive guide wear may result if oversize seals
are not used with oversize valves.
(3) Install valve springs and retainers. Compress
valve springs only enough to install locks, taking
care not to misalign the direction of compression.
Nicked valve stems may result from misalignment of
the valve spring compressor.
CAUTION: When depressing the valve spring retain-
ers with valve spring compressor the locks can
become dislocated. Ensure both locks are in the
correct location after removing tool.
(4) Check the valve spring installed height B after
refacing the valve and seat (Fig. 29). Make sure mea-
surements are taken from top of spring seat to the
bottom surface of spring retainer. If height is greater
than 38.75 mm (1.525 in.), install a 0.762 mm (0.030
in.) spacer under the valve spring seat to bring
spring height back within specification.
HYDRAULIC LIFTERS
DIAGNOSIS AND TESTING - LASH ADJUSTER
(TAPPET) NOISE DIAGNOSIS
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.
Fig. 27 Valve Stem Seal/Valve Spring Seat - Typical
1 - 3-GROOVE -VALVE RETAINING LOCKS
2 - VALVE SPRING
3 - VALVE SEAL AND VALVE SPRING SEAT ASSEMBLY
4 - VALVE SPRING RETAINER
Fig. 28 Valve Stem Oil Seal Tool
1 - VALVE SEAL TOOL
2 - VALVE STEM
9s - 28 ENGINEKJ
VALVE SPRINGS (Continued)

shown in (Fig. 34). Refer to for Engine Specifications
(Refer to 9 - ENGINE - SPECIFICATIONS). Correct
piston to bore clearance must be established in order
to assure quiet and economical operation.
NOTE: Pistons and cylinder bores should be mea-
sured at normal room temperature, 21ÉC (70ÉF).
STANDARD PROCEDURE - CYLINDER BORE
HONING
(1) Used carefully, the cylinder bore resizing hone,
recommended tool C-823 or equivalent, equipped
with 220 grit stones, is the best tool for this honing
procedure. In addition to deglazing, it will reduce
taper and out-of-round as well as removing light
scuffing, scoring or scratches. Usually a few strokes
will clean up a bore and maintain the required lim-
its.
(2) Deglazing of the cylinder walls may be done
using a cylinder surfacing hone, recommended toolC-3501 or equivalent, equipped with 280 grit stones,
if the cylinder bore is straight and round. 20±60
strokes depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Use a light
honing oil.Do not use engine or transmission oil,
mineral spirits or kerosene.Inspect cylinder walls
after each 20 strokes.
(3) Honing should be done by moving the hone up
and down fast enough to get a cross-hatch pattern.
When hone marksintersectat 40-60 degrees, the
cross hatch angle is most satisfactory for proper seat-
ing of rings (Fig. 36).
(4) A controlled hone motor speed between
200±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 40±60
degree angle. Faster up and down strokes increase
the cross-hatch angle.
(5) After honing, it is necessary that the block be
cleaned again to remove all traces of abrasive.
CAUTION: Ensure all abrasives are removed from
engine parts after honing. It is recommended that a
solution of soap and hot water be used with a
brush and the parts then thoroughly dried. The bore
can be considered clean when it can be wiped
clean with a white cloth and cloth remains clean.
Oil the bores after cleaning to prevent rusting.
CLEANING
Clean cylinder block thoroughly using a suitable
cleaning solvent.
Fig. 34 Checking Cylinder Bore -Typical
Fig. 35 Piston Measurement - Typical
Fig. 36 Cylinder Bore Cross-Hatch Pattern
1 - CROSS-HATCH PATTERN
2 - 40ɱ60É
KJENGINE9s-31
ENGINE BLOCK (Continued)

INSTALLATION
(1) Before installing pistons and connecting rod
assemblies into the bore, be sure that compression
ring gaps are staggered so that neither is in line with
oil ring rail gap.
(2) Before installing the ring compressor, make
sure the oil ring expander ends are butted and the
rail gaps located as shown in (Fig. 62). As viewed
from top.
(3) Immerse the piston head and rings in clean
engine oil, slide the ring compressor, over the piston
(Fig. 63).Be sure position of rings does not
change during this operation.
(4) The directional stamp on the piston should face
toward the front of the engine.
(5) Rotate crankshaft so that the connecting rod
journal is on the center of the cylinder bore. Insert
rod and piston assembly into cylinder bore and guide
rod over the crankshaft journal.(6) Tap the piston down in cylinder bore, using a
hammer handle. At the same time, guide connecting
rod into position on connecting rod journal.
NOTE: The connecting rod cap bolts should not be
reused.
(7) Before installing theNEWbolts the threads
should be coated with clean engine oil.
(8) Install each bolt finger tight than alternately
torque each bolt to assemble the cap properly.
CAUTION: Do not use a torque wrench for second
part of last step.
(9) Tighten the bolts to 54 N´m PLUS 1/4 turn (40
ft. lbs. PLUS 1/4 turn).
(10) Using a feeler gauge, check connecting rod
side clearance (Fig. 64).
Fig. 61 Identify Connecting Rod to Cylinder
Fig. 62 Piston Ring End Gap Position
1 - GAP OF LOWER SIDE RAIL
2 - NO. 1 RING GAP
3 - GAP OF UPPER SIDE RAIL
4 - NO. 2 RING GAP AND SPACER EXPANDER GAP
Fig. 63 PistonÐInstallation
Fig. 64 Checking Connecting Rod Side Clearance
KJENGINE9s-41
PISTON & CONNECTING ROD (Continued)

LUBRICATION
DESCRIPTION
The lubrication system is a full-flow filtration,
pressure feed type. The oil pump is mounted in the
front engine cover and driven by the crankshaft.
OPERATION
Engine oil drawn up through the pickup tube and
is pressurized by the oil pump and routed through
the full-flow filter to the main oil gallery running the
length of the cylinder block. A diagonal hole in each
bulkhead feeds oil to each main bearing. Drilled pas-
sages within the crankshaft route oil from main bear-
ing journals to connecting rod journals. Balance shaft
lubrication is provided through an oil passage from
the number one main bearing cap through the bal-
ance shaft carrier support leg. This passage directly
supplies oil to the front bearings and internal
machined passages in the shafts that routes oil from
front to the rear shaft bearing journals. A vertical
hole at the number five bulkhead routes pressurized
oil through a restrictor (integral to the cylinder head
gasket) up past a cylinder head bolt to an oil gallery
running the length of the cylinder head. The cam-
shaft journals are partially slotted to allow a prede-
termined amount of pressurized oil to pass into the
bearing cap cavities. Lubrication of the camshaft
lobes are provided by small holes in the camshaft
bearing caps that are directed towards each lobe. Oil
returning to the pan from pressurized components
supplies lubrication to the valve stems. Cylinder
bores and wrist pins are splash lubricated from
directed slots on the connecting rod thrust collars.
DIAGNOSIS AND TESTING - ENGINE OIL
PRESSURE CHECKING
(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 fitting.
(3) Start engine and record oil pressure. Refer to
Specifications for correct oil pressure requirements.
(Refer to 9 - ENGINE - SPECIFICATIONS)
CAUTION: If oil pressure is 0 at idle, do not perform
the 3000 RPM test
(4) If oil pressure is 0 at idle. Shut off engine,
check for pressure relief valve stuck open, a clogged
oil pick-up screen or a damaged oil pick-up tube
O-ring.
(5) After test is complete, remove test gauge and
fitting.
Fig. 76 TRANSMISSION MOUNT 3.7L 2WD AUTO
TRANS
1 - BOLT
2 - MOUNT
Fig. 77 TRANSMISSION MOUNT 3.7L 4WD AUTO
TRANS
1 - MOUNT
2 - BOLT
9s - 46 ENGINEKJ
LUBRICATION (Continued)

(6) Install oil pressure switch and connector. (Refer
to 9 - ENGINE/LUBRICATION/OIL PRESSURE
SENSOR/SWITCH - INSTALLATION)
OIL
STANDARD PROCEDURE
ENGINE OIL LEVEL CHECK
The best time to check engine oil level is after it
has sat overnight, or if the engine has been running,
allow the engine to be shut off for at least 5 minutes
before checking oil level.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil level
reading. Remove dipstick and observe oil level. Add
oil only when the level is at or below the ADD mark
(Fig. 78).
STANDARD PROCEDURE - ENGINE OIL AND
FILTER CHANGE
Change engine oil at mileage and time intervals
described in the Maintenance Schedule. (Refer to
LUBRICATION & MAINTENANCE/MAINTE-
NANCE SCHEDULES - DESCRIPTION)
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. CONTACT YOUR DEALER OR GOVERN-
MENT AGENCY FOR LOCATION OF COLLECTION
CENTER IN YOUR AREA.
Run engine until achieving normal operating tem-
perature.
(1) Position the vehicle on a level surface and turn
engine off.(2) Hoist and support vehicle on safety stands.
Refer to Hoisting and Jacking Recommendations.
(Refer to LUBRICATION & MAINTENANCE/HOIST-
ING - STANDARD PROCEDURE)
(3) Remove oil fill cap.
(4) Place a suitable drain pan under crankcase
drain.
(5) Remove drain plug from crankcase and allow
oil to drain into pan. Inspect drain plug threads for
stretching or other damage. Replace drain plug and
gasket if damaged.
(6) Remove oil filter. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL FILTER - REMOVAL)
(7) Install and tighten drain plug in crankcase.
(8) Install new oil filter. (Refer to 9 - ENGINE/LU-
BRICATION/OIL FILTER - INSTALLATION)
(9) Lower vehicle and fill crankcase with specified
type and amount of engine oil. (Refer to LUBRICA-
TION & MAINTENANCE/FLUID TYPES -
DESCRIPTION)
(10) Install oil fill cap.
(11) Start engine and inspect for leaks.
(12) Stop engine and inspect oil level.
NOTE: Care should be exercised when disposing
used engine oil after it has been drained from a
vehicle engine. Refer to the WARNING listed above.
OIL FILTER
DESCRIPTION
The engine oil filter is a high quality full-flow, dis-
posable type. Replace the oil filter with a Mopartor
the equivalent.
REMOVAL
(1) Raise vehicle on hoist.
(2) Position an oil collecting container under oil fil-
ter location.
CAUTION: When servicing the oil filter avoid
deforming the filter can by installing the remove/in-
stall tool band strap against the can to base lock
seam. The lock seam joining the can to the base is
reinforced by the base plate.
(3) Using a suitable filter wrench, turn oil filter
counterclockwise to remove (Fig. 79).
INSTALLATION
(1) Clean and check filter mounting surface. The
surface must be smooth, flat and free of debris or
pieces of gasket.
(2) Lubricate new oil filter gasket with clean
engine oil.
Fig. 78 Oil Level
1 - ENGINE OIL LEVEL DIPSTICK
KJENGINE9s-47
LUBRICATION (Continued)

(3) Screw oil filter on until the gasket contacts
base. Tighten to 21 N´m (15 ft. lbs.).
OIL PAN
REMOVAL
(1) Remove air cleaner assembly.
(2) Raise vehicle on hoist and drain engine oil.
(3) Loosen the engine mount thru bolts.
(4) Disconnect exhaust pipe at manifold.
(5) Remove structural collar, if equipped.
(6) Remove front axle mounting bolts, and lower
axle as far possible, if equipped.
(7) Using suitable jack, raise engine as needed.
(8) Remove oil pan attaching bolts.
(9) Remove oil pan.
(10) Clean oil pan and all gasket surfaces.
INSTALLATION
(1) Install the oil pan gasket to the block.
(2) Apply a 3MM (1/8 inch) bead of MopartEngine
RTV at the oil pump to engine block parting line
(Fig. 80).
(3) Install pan and tighten the screws to 12 N´m
(105 in. lbs.).
(4) Lower engine, and remove jack.
(5) Tighten engine mount thru bolts.
(6) Raise the front axle into position, and reinstall
front axle mounting bolts. If equipped.
(7) Reconnect exhaust pipe to manifold.
(8) Install structural collar, if equipped.
(9) Lower vehicle.(10) Fill engine crankcase with proper oil to cor-
rect level.
(11) Reinstall air cleaner assembly.
OIL PRESSURE SENSOR/
SWITCH
DESCRIPTION
The 3±wire, electrical/mechanical engine oil pres-
sure sensor (sending unit) is located in an engine oil
pressure gallery.
OPERATION
The oil pressure sensor uses three circuits. They
are:
²A 5±volt power supply from the Powertrain Con-
trol Module (PCM)
²A sensor ground through the PCM's sensor
return
²A signal to the PCM relating to engine oil pres-
sure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor. Meaning different pressures
relate to different output voltages.
A 5±volt supply is sent to the sensor from the PCM
to power up the sensor. The sensor returns a voltage
signal back to the PCM relating to engine oil pres-
sure. This signal is then transferred (bussed) to the
Fig. 79 2.4 OIL FILTERFig. 80 OIL PAN GASKET INSTALLATION
1 - SEALER LOCATION
9s - 48 ENGINEKJ
OIL FILTER (Continued)

(1) Set crankshaft sprocket to TDC by aligning the
sprocket with the arrow on the oil pump housing.
(2) Set camshafts timing marks so that the
exhaust camshaft sprocket is a 1/2 notch below the
intake camshaft sprocket (Fig. 99).
CAUTION: Ensure that the arrows on both camshaft
sprockets are facing up.
(3) Install timing belt. Starting at the crankshaft,
go around the water pump sprocket, idler pulley,
camshaft sprockets and then around the tensioner
(Fig. 100).
(4) Move the exhaust camshaft sprocket counter-
clockwise (Fig. 100) to align marks and take up belt
slack.
(5) Inserta6mmAllen wrench into the hexagon
opening located on the top plate of the belt tensioner
pulley. Rotate the top plateCOUNTERCLOCK-
WISE. The tensioner pulley will move against the
belt and the tensioner setting notch will eventually
start to move clockwise. Watching the movement of
the setting notch, continue rotating the top plate
counterclockwise until the setting notch is aligned
with the spring tang (Fig. 101). Using the allen
wrench to prevent the top plate from moving, torque
the tensioner lock nut to 30 N´m (22 ft. lbs.). Setting
notch and spring tang should remain aligned after
lock nut is torqued.
(6) Remove allen wrench and torque wrench.NOTE: Repositioning the crankshaft to the TDC
position must be done only during the CLOCKWISE
rotation movement. If TDC is missed, rotate a fur-
ther two revolutions until TDC is achieved. DO NOT
rotate crankshaft counterclockwise as this will
make verification of proper tensioner setting impos-
sible.
(7) Once the timing belt has been installed and
tensioner adjusted, rotate the crankshaft CLOCK-
WISE two complete revolutions manually for seating
of the belt, until the crankshaft is repositioned at the
TDC position. Verify that the camshaft and crank-
shaft timing marks are in proper position (Fig. 102).
Fig. 99 Camshaft Sprocket Alignment
1 - CAMSHAFT SPROCKET-EXHAUST
2 - CAMSHAFT SPROCKET-INTAKE
3 - 1/2 NOTCH LOCATION
Fig. 100 Timing Belt - Installation - Typical
1 - ROTATE CAMSHAFT SPROCKET TO TAKE UP BELT SLACK
2 - CAMSHAFT TIMING MARKS 1/2 NOTCH LOCATION
3 - CRANKSHAFT AT TDC
4 - INSTALL BELT IN THIS DIRECTION
KJENGINE9s-57
TIMING BELT AND SPROCKET(S) (Continued)