2002 JEEP GRAND CHEROKEE Oil leak

²Step 2: Verify that bolts 1±10, all reached 27
N´m (20 ft. lbs.), by repeating step-1 without loosen-
ing the bolts. Tighten bolts 11 thru 14 to 14 N´m (10
ft. lbs.).
²Step 3: Tighten bolts 1±10, 90 degrees.
²Step 4: Tighten bolts 1±10, 90 degrees, again.
Tighten bolts 11±14, 26 N´m (19 ft. lbs.)
(7) Install the secondary chain and secondary
chain guide (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT/CHAIN AND SPROCKETS -
INSTALLATION).
(8) Install the cylinder head access plug.
(9) Re-set and install the right side secondary
chain tensioner (Refer to 9 - ENGINE/VALVE TIM-
ING/TIMING BELT/CHAIN AND SPROCKETS -
INSTALLATION).
(10) Remove Special Tool 8515.
(11) Install the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(12) Install the crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION).
(13) Install accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(14) Install the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(15) Install the intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(16) Install oil fill housing onto cylinder head.
(17) Refill the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(18) Raise the vehicle.
(19) Install the exhaust pipe onto the right
exhaust manifold.
(20) Lower the vehicle.
(21) Reconnect battery negitive cable.
(22) Start the engine and check for leaks.CAMSHAFT(S) - RIGHT
DESCRIPTION
The camshafts consist of powdered metal steel
lobes which are sinter-bonded to a steel tube. A steel
post or nose piece is friction-welded to the steel cam-
shaft tube. Five bearing journals are machined into
the camshaft, four on the steel tube and one on the
steel nose piece. Camshaft end play is controlled by
two thrust walls that border the nose piece journal.
Engine oil enters the hollow camshafts at the third
journal and lubricates every intake lobe rocker
through a drilled passage in the intake lobe.
REMOVAL
CAUTION: When the timing chain is removed and
the cylinder heads are still installed, DO NOT force-
fully rotate the camshafts or crankshaft indepen-
dently of each other. Severe valve and/or piston
damage can occur.
CAUTION: When removing the cam sprocket, timing
chains or camshaft, Failure to use special tool 8350
will result in hydraulic tensioner ratchet over exten-
sion, Requiring timing chain cover removal to re-set
the tensioner ratchet.
(1) Remove the cylinder head covers (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Set engine to TDC cylinder #1, camshaft
sprocket V8 marks at the 12 o'clock position.
(3) Mark one link on the secondary timing chain
on both sides of the V8 mark on the camshaft
sprocket to aid in installation.
CAUTION: Do not hold or pry on the camshaft tar-
get wheel for any reason, Severe damage will occur
to the target wheel. A damaged target wheel could
cause a vehicle no start condition.
(4) Loosen butDO NOTremove the camshaft
sprocket retaining bolt. Leave bolt snug against
sprocket.
NOTE: The timing chain tensioners must be
secured prior to removing the camshaft sprockets.
Failure to secure tensioners will allow the tension-
ers to extend, requiring timing chain cover removal
in order to reset tensioners.
CAUTION: Do not force wedge past the narrowest
point between the chain strands. Damage to the
tensioners may occur.
Fig. 30 Cylinder Head Tightening Sequence
9 - 100 ENGINE - 4.7LWJ
CYLINDER HEAD - RIGHT (Continued)

(1) Lubricate upper main bearing halves with
clean engine oil.
CAUTION: When installing crankshaft, use care not
to damage bearing surfaces on the crankshaft.
NOTE: Apply sealant to the target wheel retaining
screws prior to installation.
(2) Install the crankshaft target wheel. Torque the
mounting screws to 22 N´m (21 ft. lbs.).
(3) Position crankshaft in cylinder block.
(4) Install the thrust washers (Fig. 55).
CAUTION: The bedplate to cylinder block mateing
surface must be coated with sealant prior to instal-
lation. Failure to do so will cause severe oil leaks.
NOTE: The installation time to install the bedplate
after the sealant has been applied is critical.
NOTE: Make sure that the bedplate and cylinder
block sealing surfaces are clean and free of oil or
other contaminants. Contaminants on the sealing
surfaces may cause main bearing distortion and/or
oil leaks.
(5) Apply a 2.5mm (0.100 inch) (Fig. 56) bead of
MopartGen II Silicone Rubber Adhesive sealant to
the cylinder block-to-bedplate mating surface as
shown (Fig. 57).(6) Coat the crankshaft main bearing journals
with clean engine oil and position the bedplate onto
the cylinder block.
NOTE: Lubricate the bedplate retaining bolts with
clean engine oil prior to installation.
(7) Install the bedplate retaining bolts, making
sure to place the stud bolts in the correct location,
Torque the bolts in the sequence shown (Fig. 58).
²Tighten boltsA± Lto 54 N´m (40 ft. lbs.)
²Tighten bolts1±10to 2.8 N´m (25 in. lbs.)
²Turn bolts1±10an additional 90É.
Fig. 55 Crankshaft Thrust Washer Installation
1 - CRANKSHAFT THRUST WASHER
Fig. 56 Cutting Aplicator to Achieve 2.5mm (0.100
in.) Bead
1 - CUT HERE
Fig. 57 Cylinder Block-to-Bedplate Sealent Bead
Location
1 - CYLINDER BLOCK
2 - SEALANT BEAD LOCATION
WJENGINE - 4.7L 9 - 113
CRANKSHAFT (Continued)

ENGINE LUBRICATION FLOW CHARTÐBLOCK: TABLE 1
FROM TO
Oil Pickup Tube Oil Pump
Oil Pump Oil Filter
Oil Filter Block Main Oil Gallery
Block Main Oil Gallery 1. Crankshaft Main Journal
2. Left Cylinder Head*
3. Right Cylinder Head*
Crankshaft Main Journals Crankshaft Rod Journals
Crankshaft Number One Main Journal 1.Front Timing Chain Idler Shaft
2.Both Secondary Chain Tensioners
Left Cylinder Head See Table 2
Right Cylinder Head See Table 2
* The cylinder head
gaskets have an oil restricter to control oil flow to the cylinder heads.
ENGINE LUBRICATION FLOW CHARTÐCYLINDER HEADS: TABLE 2
FROM TO
Cylinder Head Oil Port (in bolt hole) Diagonal Cross Drilling to Main Oil Gallery
Main Oil Gallery (drilled through head from rear to
front)1. Base of Camshaft Towers
2. Lash Adjuster Towers
Base of Camshaft Towers Vertical Drilling Through Tower to Camshaft Bearings**
Lash Adjuster Towers Diagonal Drillings to Hydraulic Lash Adjuster Pockets
** The number three camshaft bearing journal feeds oil into the hollow camshaft tubes. Oil is routed to the intake
lobes, which have oil passages drilled into them to lubricate the rocker arms.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐENGINE OIL
PRESSURE
(1) Remove oil pressure sending unit (Fig. 89)and
install gauge assembly C-3292.
(2) Run engine until thermostat opens.
(3) Oil Pressure:
²Curb IdleÐ25 Kpa (4 psi) minimum
²3000 rpmÐ170 - 550 KPa (25 - 80 psi)
(4) If oil pressure is 0 at idle, shut off engine.
Check for a clogged oil pick-up screen or a pressure
relief valve stuck open.
DIAGNOSIS AND TESTINGÐREAR 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, distributor seal,
camshaft bore cup plugs, oil galley pipe plugs, oil
filter runoff, and main bearing cap to cylinder
block mating surfaces. 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).
9 - 128 ENGINE - 4.7LWJ
LUBRICATION (Continued)

(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).
DIAGNOSIS AND TESTINGÐENGINE OIL LEAK
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair per service manual instructions.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24km (15 miles), and
repeat inspection.If the oil leak source is not pos-
itively identified at this time, proceed with the air
leak detection test method.
Air Leak Detection Test Method
(1) Disconnect the breather cap to air cleaner hose
at the breather cap end. Cap or plug breather cap
nipple.
(2) Remove the PCV valve from the cylinder head
cover. Cap or plug the PCV valve grommet.
(3) Attach an air hose with pressure gauge and
regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
(4) Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provide the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
(5) If the leakage occurs at the rear oil seal area,
refer to the section, Inspection for Rear Seal Area
Leak.
(6) If no leaks are detected, turn off the air supply
and remove the air hose and all plugs and caps.
Install the PCV valve and breather cap hose.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
INSPECTION FOR 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.
Fig. 89 Oil Pressure Sending Unit
1 - BELT
2 - OIL PRESSURE SENSOR
3 - OIL FILTER
4 - ELEC. CONNECTOR
WJENGINE - 4.7L 9 - 129
LUBRICATION (Continued)

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, distributor seal,
camshaft bore cup plugs oil galley pipe plugs, oil
filter runoff, and main bearing cap to cylinder
block mating surfaces.
(4) If no leaks are detected, pressurize the crank-
case as outlined in the, 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 and
scratches. The crankshaft seal flange is especially
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.
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-
ple viscosities such as 5W-30 or 10W-30 in the 4.7L
engines.The 4.7L H.O. uses 10W-30 oil only.These
are specified with a dual SAE viscosity grade which
indicates the cold-to-hot temperature viscosity range.
Select an engine oil that is best suited to your par-
ticular temperature range and variation (Fig. 90).
ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for
gasoline engines. The designation of ENERGY CON-
SERVING is located on the label of an engine oil con-
tainer.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans (Fig. 91).
OIL LEVEL INDICATOR (DIPSTICK)
The engine oil level indicator is located on the
right side of the the 4.7L engine. (Fig. 92).
Fig. 90 Temperature/Engine Oil Viscosity - 4.7L
Engine
9 - 130 ENGINE - 4.7LWJ
LUBRICATION (Continued)

CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil,
pressure loss or oil foaming can result.
Inspect engine oil level approximately every 800
kilometers (500 miles). Unless the engine has exhib-
ited loss of oil pressure, run the engine for about five
minutes before checking oil level. Checking engine oil
level on a cold engine is not accurate.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable levels are indicated between the ADD
and SAFE marks on the engine oil dipstick.
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately ten min-
utes for oil to settle to bottom of crankcase, remove
engine oil dipstick.(3) Wipe dipstick clean.
(4) Install dipstick and verify it is seated in the
tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil if level is below the SAFE ZONE on
dipstick.
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals
described in Maintenance Schedules.
Run engine until achieving normal operating tem-
perature.
(1) Position the vehicle on a level surface and turn
engine off.
(2) Remove oil fill cap.
(3) Hoist and support vehicle on safety stands.
(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 if
damaged.
(6) Install drain plug in crankcase.
(7) Remove oil filter (Refer to 9 - ENGINE/LUBRI-
CATION/OIL FILTER - REMOVAL).
(8) Lower vehicle and fill crankcase with specified
type and amount of engine oil described in this sec-
tion.
(9) Install oil fill cap.
(10) Start engine and inspect for leaks.
(11) Stop engine and inspect oil level.
USED ENGINE OIL DISPOSAL
Care should be exercised when disposing used
engine oil after it has been drained from a vehicle
engine. Refer to the WARNING at beginning of this
section.
OIL FILTER
REMOVAL
All engines are equipped with a high quality full-
flow, disposable type oil filter. DaimlerChrysler Cor-
poration recommends a Mopartor equivalent oil
filter be used.
(1) Position a drain pan under the oil filter.
(2) Using a suitable oil filter wrench loosen filter.
(3) Rotate the oil filter counterclockwise (Fig. 93)to
remove it from the cylinder block oil filter boss.
(4) When filter separates from cylinder block oil
filter boss, tip gasket end upward to minimize oil
spill. Remove filter from vehicle.
NOTE: Make sure filter gasket was removed with fil-
ter.
Fig. 91 Engine Oil Container Standard Notations
Fig. 92 Engine Oil Dipstick 4.7L Engine
1 - TRANSMISSION DIPSTICK
2 - ENGINE OIL DIPSTICK
3 - ENGINE OIL FILL CAP
WJENGINE - 4.7L 9 - 131
OIL (Continued)

(5) With a wiping cloth, clean the gasket sealing
surface of oil and grime.
INSTALLATION
(1) Lightly lubricate oil filter gasket with engine
oil.
(2) Thread filter onto adapter nipple. When gasket
makes contact with sealing surface, (Fig. 94)hand
tighten filter one full turn, do not over tighten.
(3) Add oil, verify crankcase oil level and start
engine. Inspect for oil leaks.
OIL PAN
DESCRIPTION
The engine oil pan is made of laminated steel and
has a single plane sealing surface. The sandwich
style oil pan gasket has an integrated windage tray
and steel carrier. The sealing area of the gasket is
molded with rubber and is designed to be reused as
long as the gasket is not cut, torn or ripped.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Raise vehicle on hoist.
(3) Remove structural cover (Refer to 9 - ENGINE/
ENGINE BLOCK/STRUCTURAL COVER - REMOV-
AL).
(4) Remove exhaust system Y-pipe.
(5) Remove starter (Refer to 8 - ELECTRICAL/
STARTING/STARTER MOTOR - REMOVAL).
(6) Drain engine oil.
(7) Un-clip transmission lines from support on oil
pan stud. Move lines for oil pan clearance.
CAUTION: DO NOT pry on the oil pan gasket when
removing the oil pan, The oil pan gasket is mounted
to the cylinder block in three locations and will
remain attached to block when lowering oil pan.
Gasket can not be removed with oil pan.
(8) Remove oil pan bolts and oil pan.
(9) Remove oil pump pickup tube.
(10) Remove oil pan gasket.
CLEANING
(1) Clean oil pan in solvent and wipe dry with a
clean cloth.
(2) Clean the oil pan gasket surface.DO NOTuse
a grinder wheel or other abrasive tool to clean seal-
ing surface.
(3) Clean oil screen and tube thoroughly in clean
solvent.
INSPECTION
(1) Inspect oil drain plug and plug hole for
stripped or damaged threads. Repair as necessary.
(2) Inspect the oil pan mounting flange for bends
or distortion. Straighten flange, if necessary.
INSTALLATION
(1) Clean oil pan and all sealing surfaces. Inspect
oil pan gasket and replace as necessary.
(2) Install oil pan gasket.
Fig. 93 Oil Filter - 4.7L Engine
1 - ENGINE OIL FILTER
Fig. 94 Oil Filter Sealing SurfaceÐTypical
1 - SEALING SURFACE
2 - RUBBER GASKET
3 - OIL FILTER
9 - 132 ENGINE - 4.7LWJ
OIL FILTER (Continued)

INTAKE MANIFOLD
DESCRIPTION
The intake manifold is made of a composite mate-
rial and features long runners which maximizes low
end torque. The intake manifold uses single plane
sealing which consist of eight individual press in
place port gaskets to prevent leaks. Eight studs and
two bolts are used to fasten the intake to the head.
DIAGNOSIS AND TESTINGÐINTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.
(3) If a change in RPM is observed the area of the
suspected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove air cleaner housing and throttle body
resonator (Fig. 104).
(3) Disconnect throttle and speed control cables.
(4) Disconnect electrical connectors for the follow-
ing components:
²Manifold Absolute Pressure (MAP) Sensor
²Intake Air Temperature (IAT) Sensor
²Throttle Position (TPS) Sensor
²Coolant Temperature (CTS) Sensor
²Idle Air Control (IAC) Motor
(5) Disconnect vapor purge hose, brake booster
hose, speed control servo hose, positive crankcase
ventilation (PCV) hose.
Fig. 102 Measuring Clearance Over Rotors
1 - STRAIGHT EDGE
2 - FEELER GAUGE
Fig. 103 Oil Pump and Primary Timing Chain
Tensioner Tightening Sequence
Fig. 104 Throttle Body Resonator
1 - THROTTLE BODY RESONATOR
2 - BOLT
3 - BOLT
9 - 136 ENGINE - 4.7LWJ
OIL PUMP (Continued)