bore JEEP GRAND CHEROKEE 2003 WJ / 2.G Repair Manual

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)ÐPERFORMANCE 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).
Fig. 1 Engine Identification Location
1 - VEHICLE VIN NUMBER LOCATION
2 - CYLINDER BLOCK RIGHT HAND SIDE
3 - CYLINDER BORE #2
9 - 64 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
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.
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.
9 - 68 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)

(13) Disconnect the engine block heater power
cable from the block heater.
(14) Lower vehicle.
(15) Remove throttle body resonator assembly and
inlet hose.
(16) Disconnect throttle and speed control cables.
(17) Disconnect tube from both the left and right
side crankcase breathers, then remove the breathers
(Fig. 5).
(18) Discharge A/C system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE).(19) Remove radiator fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL) and acces-
sory drive belt (Refer to 7 - COOLING/ACCESSORY
DRIVE/DRIVE BELTS - REMOVAL).
(20) Remove A/C compressor (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - REMOVAL).
(21) Disconnect transmission oil cooler lines at the
radiator.
(22) Disconnect radiator lower hose at the thermo-
stat housing.
(23) Remove A/C condenser (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C CON-
DENSER - REMOVAL).
(24) Remove radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(25) Remove generator (Refer to 8 - ELECTRICAL/
CHARGING/GENERATOR - REMOVAL).
(26) Disconnect the two heater hoses from the tim-
ing chain cover.
(27) Disconnect engine harness at the following
points :
²Intake air temperature (IAT) sensor (Fig. 6)
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold absolute pressure (MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
(28) Release fuel rail pressure (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - STANDARD PROCE-
DURE) then disconnect the fuel supply quick connect
fitting at the fuel rail (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/QUICK CONNECT FITTING -
STANDARD PROCEDURE).
(29) Remove power steering pump and position out
of the way.
(30) Disconnect ground straps from the left side of
the engine.
(31) Install Engine Lifting Fixture Special Tool
8347 (Fig. 7)following these steps.
²Holding the lifting fixture at a slight angle, slide
the large bore in the front plate over the hex portion
of the lifting stud.
²Position the two remaining fixture arms onto
the two lifting studs in the cylinder heads.
²Pull foward and upward on the lifting fixture so
that the lifting stud rest in the slotted area below the
large bore.
²Secure the lifting fixture to the three studs
using three 7/16 ± 14 N/C locknuts.
²Make sure the lifting loop in the lifting fixture is
in the last hole (closest to the throttle body) to min-
imize the angle of engine during removal.
Fig. 4 Crankshaft Position Sensor
1 - CRANKSHAFT POSITION SENSOR
2 - CYLINDER HEAD COVER
3 - CAMSHAFT POSITION SENSOR
4 - RIGHT SIDE CYLINDER BLOCK
Fig. 5 Crankcase Breather Connection Points
1 - CRANKCASE BREATHERS
9 - 72 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)

²Camshaft Position (CMP) Sensor
²Coil Over Plugs
(10) Install generator (Refer to 8 - ELECTRICAL/
CHARGING/GENERATOR - INSTALLATION).
(11) Install radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - INSTALLATION).
(12) Install A/C condenser (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/A/C CON-
DENSER - INSTALLATION).
(13) Connect radiator lower hose at the thermostat
housing.
(14) Connect the transmission oil cooler lines to
the radiator.
(15) Install A/C compressor. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - INSTALLATION).
(16) Install accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION) and radiator fan (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - INSTALLA-
TION).
(17) Install breathers, then connect tube to both
crankcase breathers (Fig. 5).
(18) Connect throttle and speed control cables.
(19) Install throttle body resonator assembly and
inlet hose.
(20) Raise vehicle.
(21) Connect two ground straps on the lower left
hand side of the engine and one ground strap on the
lower right side.
(22) Install torque converter bolts.
(23) Connect crankshaft position sensor (Fig. 4).
(24) Install starter.
(25) Install rubber splash shield.
CAUTION: The structural cover requires a specific
torque sequence. Failure to follow this sequence
may cause severe damage to the cover.
(26) Install structural cover (Refer to 9 - ENGINE/
ENGINE BLOCK/STRUCTURAL COVER - INSTAL-
LATION).
(27) Install exhaust crossover pipe.
(28) Install engine block heater power cable, If
equipped.
(29) Lower vehicle.
(30) Check and fill engine oil (Refer to LUBRICA-
TION & MAINTENANCE/FLUID TYPES - SPECIFI-
CATIONS).
(31) Recharge the A/C system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE).
(32) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(33) Connect the battery negative cable.
(34) Start engine and check for leaks.SPECIFICATIONS
4.7L 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 9.0:1
Horsepower 235 BHP @ 4800 RPM
Torque 295 LB-FT @ 3200 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 367.5 grams (12.96 oz)
Ring Groove Diameter
No. 1 83.73 - 83.97 mm
(3.296 - 3.269 in.)
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 Pressed Fit
Clearance In Piston 0.010 - 0.019 mm
(0.0004 - 0.0008 in.)
Diameter 24.013 - 24.016 mm
(0.9454 - 0.9456 in.)
9 - 74 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)

DESCRIPTION SPECIFICATION
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.)
Side Clearance 0.10 - 0.35 mm
(0.004 - 0.0138 in.)
Piston Pin Bore Diameter .022 - .045 mm
(Interference Fit) (0.0009 - 0.0018 in.)
Bearing Bore Out of
Round0.004 mm
(MAX) (0.0002 in.)
Total Weight (Less
Bearing)555 grams (19.5771
ounces)
CRANKSHAFT
Main BearingJournal
Diameter 63.488 - 63.512 mm
(2.4996 - 2.5005 in.)DESCRIPTION SPECIFICATION
Bearing Clearance 0.018 - 0.052 mm
(0.0008 - 0.0021 in.)
Out of Round (MAX) 0.005 mm (0.0002 in.)
Taper (MAX) 0.008 mm (0.0004 in.)
End Play 0.052 - 0.282 mm
(0.0021 - 0.0112 in.)
End Play (MAX) 0.282 mm (0.0112 in)
Connecting Rod
Journal
Diameter 50.992 - 51.008 mm
(2.0076 - 2.0082 in.)
Bearing Clearance 0.015 - 0.055 mm
(0.0006 -0.0022 in.)
Out of Round (MAX) 0.005 mm (0.0002 in.)
Taper (MAX) 0.008 mm (0.0004 in.)
CAMSHAFT
Bore Diameter 26.02 - 26.04 mm
(1.0245 - 1.0252 in.)
Bearing Journal Diameter 25.975 - 25.995 mm
(1.0227 - 1.0235 in.)
Bearing Clearance 0.025 - 0.065 mm
(0.001 - 0.0026 in.)
Bearing Clearance (MAX) 0.065 mm (0.0026 in.)
End Play .075 - .200 mm
(0.003 - 0.0079 in.)
End Play (MAX) .200 mm (0.0079 in.)
VALVE TIMING
Intake
Opens (ATDC) 3.6É
Closes (ATDC) 247.1É
Duration 243.5É
Exhaust
Opens (BTDC) 232.5É
Closes (ATDC) 21.2É
Duration 253.70É
Valve Overlap 17.6É
VA LV E S
Face Angle 45É - 45.5É
Head Diameter
Intake 48.52 - 48.78 mm
(1.9103 - 1.9205 in.)
WJENGINE - 4.7L 9 - 75
ENGINE - 4.7L (Continued)

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
Side Clearance 0.10 - 0.35 mm
(0.004 - 0.0138 in.)
Piston Pin Bore Diameter 24.045 - 24.035 mm
(0.94665 - 0.94625 in.)
Bearing Bore Out of
Round0.004 mm
(MAX) (0.0002 in.)
Total Weight (Less
Bearing)555 grams (19.5771
ounces)
CRANKSHAFT
Main BearingJournal
Diameter 63.488 - 63.512 mm
(2.4996 - 2.5005 in.)
Bearing Clearance 0.018 - 0.052 mm
(0.0008 - 0.0021 in.)
Out of Round (MAX) 0.005 mm (0.0002 in.)
Taper (MAX) 0.008 mm (0.0004 in.)
End Play 0.052 - 0.282 mm
(0.0021 - 0.0112 in.)
End Play (MAX) 0.282 mm (0.0112 in)
Connecting Rod
Journal
Diameter 50.992 - 51.008 mm
(2.0076 - 2.0082 in.)
Bearing Clearance 0.015 - 0.055 mm
(0.0006 -0.0022 in.)
Out of Round (MAX) 0.005 mm (0.0002 in.)
Taper (MAX) 0.008 mm (0.0004 in.)
CAMSHAFT
Bore Diameter 26.02 - 26.04 mm
(1.0245 - 1.0252 in.)
Bearing Journal Diameter 25.975 - 25.995 mm
(1.0227 - 1.0235 in.)
Bearing Clearance 0.025 - 0.065 mm
(0.001 - 0.0026 in.)
Bearing Clearance (MAX) 0.065 mm (0.0026 in.)
End Play .075 - .200 mm
(0.003 - 0.0079 in.)
End Play (MAX) .200 mm (0.0079 in.)DESCRIPTION SPECIFICATION
VALVE TIMING
Intake
Opens (BTDC) 3.0É
Closes (ATDC) 233.0É
Duration 236.0É
Exhaust
Opens (BTDC) 235.0É
Closes (ATDC) 15.0É
Duration 250.0É
Valve Overlap 18.0É
VA LV E S
Face Angle 45É - 45.5É
Head Diameter
Intake 48.52 - 48.78 mm
(1.9103 - 1.9205 in.)
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.)
9 - 78 ENGINE - 4.7LWJ
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)

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)