2003 JEEP GRAND CHEROKEE compress

DESCRIPTION SPECIFICATION
Exhaust 36.87 - 37.13 mm
1.4516 - 1.4618 in.)
Length (Overall)
Intake 113.45 - 114.21 mm
(4.4666 - 4.4965)
Exhaust 114.92 - 115.68 mm
(4.5244 - 4.5543 in.)
Stem Diameter
Intake 6.931 - 6.957 mm
(0.2729 - 0.2739 in.)
Exhaust 6.902 - 6.928 mm
(0.2717 - 0.2728 in.)
Stem - to - Guide
Clearance
Intake .018 - .069 mm
(0.0008 - 0.0028 in.)
Exhaust .047 - .098 mm
(0.0019 - 0.0039 in.)
Max. Allowable Stem -
to -
Guide Clearance
(Rocking
Method)
Intake 0.069 mm (0.0028 in.)
Exhaust 0.098 mm (0.0039 in.)
Valve Lift (Zero Lash)
Intake 11.25 mm (0.443 in.)
Exhaust 10.90 mm (0.4292 in.)
VALVE SPRING
Free Length (Approx)
Intake and Exhaust 48.6 mm (1.9134 in.)
Spring Force (Valve
Closed)
Intake and Exhaust 315.5 - 352.5 N @ 40.89
mm
(70.92722 - 79.24515 lbs.
@ 1.6099 in.)DESCRIPTION SPECIFICATION
Spring Force (Valve
Open)
Intake and Exhaust 786.0 - 860.0 N @ 29.64
mm
176.6998 - 193.3357 lbs.
@ 1.167 in.)
Number of Coils
Intake and Exhaust 6.69
Wire Diameter
Intake and Exhaust 4.2799 - 4.3561 mm
(0.1685 - 0.1715 in.)
Installed Height (Spring
Seat to Bottom of
Retainer)
Nominal
Intake 40.97 mm (1.613 in.)
Exhaust 40.81 mm (1.606 in.)
CYLINDER HEAD
Gasket Thickness
(Compressed) .7 mm (0.0276 in.)
Valve Seat Angle 44.5É - 45.0É
Valve Seat Runout (MAX) 0.051 mm (0.002 in.)
Valve Seat Width
Intake 1.75 - 2.36 mm
(0.0698 - 0.0928 in.)
Exhaust 1.71 - 2.32 mm
(0.0673 - 0.0911 in.)
Guide Bore Diameter
(Std.)6.975 - 7.00 mm
(0.2747 - 0.2756 in.)
Cylinder Head Warpage
(Flatness) 0.0508 mm (0.002 in.)
OIL PUMP
Clearance Over Rotors /
End Face (MAX).035 - .095 mm
(0.0014 - 0.0038 in.)
Cover Out - of -Flat
(MAX).025 mm (0.001 in.)
Inner and Outer Rotor
Thickness 12.02 mm (0.4731 in.)
9 - 76 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)

DESCRIPTION SPECIFICATION
Outer Rotor Clearance
(MAX).235 mm (.0093 in.)
Outer Rotor Diameter
(MIN)85.925 mm (0.400 in.)
Tip Clearance Between
Rotors
(MAX) .150 mm (0.006 in.)
OIL PRESSURE
At Curb Idle Speed
(MIN)*25 kPa (4 psi)
@ 3000 rpm 170 - 758 kPa (25 - 110
psi)
* CAUTION: If pressure is zero at curb idle, DO
NOT run
engine at 3000 rpm.
SPECIFICATIONS - 4.7L H.O. ENGINE
DESCRIPTION SPECIFICATION
GENERAL SPECIFICATIONS
Engine Type 90É SOHC V-8 16-Valve
Displacement 4.7 Liters / 4701cc
(287 Cubic Inches)
Bore 93.0 mm (3.66 in.)
Stroke 86.5 mm (3.40 in.)
Compression Ratio 9.7:1
Horsepower 270 BHP @ 5100 RPM
Torque 330 LB-FT @ 3600 RPM
Lead Cylinder #1 Left Bank
Firing Order 1-8-4-3-6-5-7-2
CYLINDER BLOCK
Cylinder Block Cast Iron
Bore Diameter 93.010   .0075 mm
(3.6619   0.0003 in.)
Out of Round (MAX) 0.076 mm (0.003 in.)
Taper (MAX) 0.051 mm (0.002 in.)
PISTONS
Material Aluminum Alloy
Diameter 92.975 mm (3.6605 in.)
Weight 383.5 grams (13.52 oz)
Ring Groove Diameter
No. 1 83.37 - 83.13 mm
(3.296 - 3.269 in.)
DESCRIPTION SPECIFICATION
No. 2 82.833 - 83.033 mm
(3.261 - 3.310 in.)
No. 3 83.88 - 84.08 mm
(3.302 - 3.310 in.)
PISTON PINS
Type Full Floating
Clearance In Piston 0.010 - 0.019 mm
(0.0004 - 0.0008 in.)
Clearance in Rod 0.006 - 0.015 mm
(0.0002 - 0.0005 in.)
Diameter 24.017 - 24.020 mm
(0.9455 - 0.9456 in.)
PISTON RINGS
Ring Gap
Top Compression Ring 0.37 - 0.63 mm
(0.0146 - 0.0249 in.)
Second Compression
Ring0.37 - 0.63 mm
(0.0146 - 0.0249 in.)
Oil Control (Steel Rails) 0.25 - 0.76 mm
(0.0099 - 0.30 in.)
Side Clearance
Top Compression Ring .051 - .094 mm
(0.0020 - 0.0037 in.)
Second Compression
Ring0.040 - 0.080 mm
(0.0016 - 0.0031 in.)
Oil Ring (Steel Ring) .019 - .229 mm
(.0007 - .0091 in.)
Ring Width
Top Compression Ring 1.472 - 1.490 mm
(0.057 - 0.058 in.)
Second Compression
Ring1.472 - 1.490 mm
(0.057 - 0.058 in.)
Oil Ring (Steel Rails) 0.445 - 0.470 mm
(0.017 - 0.018 in.)
CONNECTING RODS
Bearing Clearance 0.010 - 0.048 mm
(0.0004 - 0.0019 in.)
WJENGINE - 4.7L 9 - 77
ENGINE - 4.7L (Continued)

DESCRIPTION SPECIFICATION
Valve Lift (Zero Lash)
Intake 12.00 mm (0.4724 in.)
Exhaust 10.90 mm (0.4292 in.)
VALVE SPRING
Free Length (Approx)
Intake and Exhaust 48.92 mm (1.9259 in.)
Spring Force (Valve
Closed)
Intake and Exhaust 380.0 +/- 19.0 N @ 40.12
mm
(85.4274 lbs. @ 1.5795
in.)
Spring Force (Valve
Open)
Intake and Exhaust 1030.0 +/- 46.0 N @
28.12 mm
231.5532 lbs. @ 1.107
in.)
Number of Coils
Intake and Exhaust 7.30
Wire Diameter
Intake and Exhaust 4.77 +/- 0.03 mm x
3.80+/- .03mm
Installed Height (Spring
Seat to Bottom of
Retainer)
Nominal
Intake 40.97 mm (1.613 in.)
Exhaust 40.81 mm (1.606 in.)
CYLINDER HEAD
Gasket Thickness
(Compressed) .7 mm (0.0276 in.)
Valve Seat Angle 44.5É - 45.0É
Valve Seat Runout (MAX) 0.051 mm (0.002 in.)
Valve Seat Width
Intake 1.75 - 2.36 mm
(0.0698 - 0.0928 in.)
Exhaust 1.71 - 2.32 mm
(0.0673 - 0.0911 in.)
Guide Bore Diameter
(Std.)6.975 - 7.00 mm
(0.2747 - 0.2756 in.)DESCRIPTION SPECIFICATION
Cylinder Head Warpage
(Flatness) 0.0508 mm (0.002 in.)
OIL PUMP
Clearance Over Rotors /
End Face (MAX).035 - .095 mm
(0.0014 - 0.0038 in.)
Cover Out - of -Flat
(MAX).025 mm (0.001 in.)
Inner and Outer Rotor
Thickness 12.02 mm (0.4731 in.)
Outer Rotor Clearance
(MAX).235 mm (.0093 in.)
Outer Rotor Diameter
(MIN)85.925 mm (0.400 in.)
Tip Clearance Between
Rotors
(MAX) .150 mm (0.006 in.)
OIL PRESSURE
At Curb Idle Speed
(MIN)*25 kPa (4 psi)
@ 3000 rpm 170 - 758 kPa (25 - 110
psi)
* CAUTION: If pressure is zero at curb idle, DO
NOT run
engine at 3000 rpm.
TORQUE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Camshaft
Non - Oiled Sprocket Bolt 122 90 Ð
Bearing Cap Bolts 11 Ð 100
Timing Chain CoverÐBolts 54 40 Ð
Connecting Rod CapÐBolts 27 20 Ð
PLUS 90É TURN
Bed PlateÐBolts Refer to Procedure
Crankshaft DamperÐBolt 175 130 Ð
Cylinder HeadÐBolts
M11 Bolts 81 60 Ð
M8 Bolts 26 19 Ð
Cylinder Head CoverÐBolts 12 Ð 105
Exhaust ManifoldÐBolts 25 18 Ð
WJENGINE - 4.7L 9 - 79
ENGINE - 4.7L (Continued)

Crankshaft Damper Removal Insert 8513
Chain Tensioner Wedge 8379
Chain Tensioner Pins 8514
Secondary Chain Holder 8429
Remover, Rocker Arm 8516
Valve Spring Compressor 8387
Idler Shaft Remover 8517
Valve Spring Compressor Adapters 8519
9 - 82 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)

AIR CLEANER ELEMENT
REMOVAL - 4.7L
(1) Unlatch four clips retaining air cleaner cover to
air cleaner housing (Fig. 8).
(2) Lift cover up and position to the side.
(3) Remove air cleaner element.
INSTALLATION - 4.7L
(1) Clean inside of air cleaner housing before
installing new element.
(2) Install air cleaner element into housing.
(3) Latch clips and clamp cover down to secure. Be
sure air cleaner cover is properly seated to air
cleaner housing.
Valve Spring Tester C-647
Dial Indicator C-3339
Valve Spring Compressor C-3422-B
Bore Size Indicator C-119
Oil Pressure Gauge C-3292
Piston Ring Compressor C-385
Pressure Tester Kit 7700
Bloc±Chek±Kit C-3685±A
WJENGINE - 4.7L 9 - 83
ENGINE - 4.7L (Continued)

(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.
a. Check 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.
b. Remove suspected lash adjusters, and replace.
c. Before 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 TESTINGÐCYLINDER 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.
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 7 - COOL-
ING - STANDARD PROCEDURE).
(5) Lower the vehicle.
(6) Remove the intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL).
(7) Remove the cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(8) Remove accessory drive belt. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(9) Remove the power steering pump and set
aside.
(10) Rotate the crankshaft until the damper tim-
ing mark is aligned with TDC indicator mark (Fig.
9).
WJENGINE - 4.7L 9 - 85
CYLINDER HEAD - LEFT (Continued)

NOTE: All eight valve springs and valves are
removed in the same manner; this procedure only
covers one valve and valve spring.
(3) Using Special Tool C-3422±B or C-3422±C
Valve Spring Compressor and Special tool 8519
Adapter, compress the valve spring.
NOTE: It may be necessary to tap the top of the
valve spring to loosen the spring retainers locks
enough to be removed.
(4) Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(5) Remove the valve spring compressor.
(6) Remove the spring retainer, and the spring.
NOTE: Check for sharp edges on the keeper
grooves. Remove any burrs from the valve stem
before removing the valve from the cylinder head.
(7) Remove the valve from the cylinder head.
NOTE: The valve stem seals are common between
intake and exhaust.
(8) Remove the valve stem seal. Mark the valve for
proper installation.
TESTING VALVE SPRINGS
NOTE: Whenever the valves are removed from the
cylinder head it is recommended that the valve
springs be inspected and tested for reuse.
Inspect the valve springs for physical signs of wear
or damage. Turn table of tool C-647 until surface is
in line with the 40.69 mm (1.602 in.) mark on the
threaded stud and the zero mark on the front. Place
spring over the stud on the table and lift compress-
ing lever to set tone device. Pull on torque wrench
until Ping is heard. Take reading on torque wrench
at this instant. Multiply this reading by two. This
will give the spring load at test length. Fractional
measurements are indicated on the table for finer
adjustments. Refer to Specifications Section to obtain
specified height and allowable tensions. Replace any
springs that do not meet specifications. (Fig. 25)
INSTALLATION
(1) coat the valve stem with clean engine oil and
insert it into the cylinder head.
(2) Install the valve stem seal. make sure the seal
is fully seated and that the garter spring at the top
of the seal is intact.
(3) Install the spring and the spring retainer (Fig.
26).
(4) Using the valve spring compressor, compress
the spring and install the two valve spring retainer
halves.
(5) Release the valve spring compressor and make
sure the two spring retainer halves and the spring
retainer are fully seated.
(6) lubricate the camshaft journal with clean
engine oil then Position the camshaft (with the
sprocket dowel on the left camshaft at 11 o'clock and
the right camshaft at 12 o'clock), then position the
camshaft bearing caps.
(7) Install the camshaft bearing cap retaining
bolts. Tighten the bolts 9±13 N´m (100 in. lbs.) in
1¤2
turn increments in the sequence shown (Fig. 27).
(8) Position the hydraulic lash adjusters and
rocker arms (Fig. 24).
Fig. 25 Testing Valve Springs
1 - SPECIAL TOOL C-647
WJENGINE - 4.7L 9 - 95
INTAKE/EXHAUST VALVES & SEATS (Continued)

ROCKER ARM / ADJUSTER
ASSEMBLY
DESCRIPTION
The rocker arms are steel stampings with an inte-
gral roller bearing. The rocker arms incorporate a 2.8
mm (0.11 inch) oil hole in the lash adjuster socket for
roller and camshaft lubrication.
REMOVAL
NOTE: Disconnect the battery negative cable to pre-
vent accidental starter engagement.
(1) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) For rocker arm removal on cylinders 3 and 5
Rotate the crankshaft until cylinder #1 is at TDC
exhaust stroke.
(3) For rocker arm removal on cylinders 2 and 8
Rotate the crankshaft until cylinder #1 is at TDC
compression stroke.
(4) For rocker arm removal on cylinders 4 and 6
Rotate the crankshaft until cylinder #3 is at TDC
compression stroke.
(5) For rocker arm removal on cylinders 1 and 7
Rotate the crankshaft until cylinder #2 is at TDC
compression stroke.
(6) Using special tool 8516 Rocker Arm Remover,
press downward on the valve spring, remove rocker
arm (Fig. 28).
INSTALLATION
CAUTION: Make sure the rocker arms are installed
with the concave pocket over the lash adjusters.
Failure to do so may cause severe damage to the
rocker arms and/or lash adjusters.
NOTE: Coat the rocker arms with clean engine oil
prior to installation.
(1) For rocker arm installation on cylinders 3 and
5 Rotate the crankshaft until cylinder #1 is at TDC
exhaust stroke.
(2) For rocker arm installation on cylinders 2 and
8 Rotate the crankshaft until cylinder #1 is at TDC
compression stroke.
(3) For rocker arm installation on cylinders 4 and
6 Rotate the crankshaft until cylinder #3 is at TDC
compression stroke.
(4) For rocker arm installation on cylinders 1 and
7 Rotate the crankshaft until cylinder #2 is at TDC
compression stroke.
Fig. 26 Valve Assembly Configuration
1 - VALVE LOCKS (3±BEAD)
2 - RETAINER
3 - VALVE STEM OIL SEAL
4 - INTAKE VALVE
5 - EXHAUST VALVE
6 - VALVE SPRING
Fig. 27 Camshaft Bearing Caps Tightening
Sequence
9 - 96 ENGINE - 4.7LWJ
INTAKE/EXHAUST VALVES & SEATS (Continued)