
ENGINE - 4.7L
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
6. Dirt or water in fuel system. 6. Clean system and replace fuel
filter.
7. Faulty fuel pump, relay or wiring. 7. Repair or replace as necessary.
ENGINE STALLS OR ROUGH IDLE 1. Idle speed set to low. 1. (Refer to 14 - FUEL SYSTEM/
FUEL INJECTION/IDLE AIR
CONTROL MOTOR - REMOVAL).
2. Idle mixture too lean or too rich. 2. Refer to Powertrain Diagnosis
Information.
3. Vacuum leak. 3. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
5. Incorrect engine timing. 5. (Refer to 9 - ENGINE/VALVE
TIMING - STANDARD
PROCEDURE).
9 - 90 ENGINE - 4.7LDR

CONDITION POSSIBLE CAUSE CORRECTION
1. ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped spark
plugs.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
2. Dirt or water in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/FUEL PUMP -
DIAGNOSIS AND TESTING).
4. Blown cylinder head gasket. 4. Replace cylinder head gasket.
5. Low compression. 5. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
6. Burned, warped or pitted valves. 6. Replace as necessary.
7. Plugged or restricted exhaust
system.7. Inspect and replace as
necessary.
8. Faulty coil. 8. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
1. ENGINE MISSES ON
ACCELERATION1. Spark plugs dirty or incorrectly
gapped.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
2. Dirt in fuel system. 2. Clean fuel system.
3. Burned, warped or pitted valves. 3. Replcae as necessary.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
1. ENGINE MISSES AT HIGH
SPEED1. Spark plugs dirty or incorrectly
gapped.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
2. Faulty coil. 2. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
3. Dirt or water in fuel system. 3. Clean system and replace fuel
filter.
DRENGINE - 4.7L 9 - 91
ENGINE - 4.7L (Continued)

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTIONS
NOISY VALVES 1. High or low oil level in
crankcase.1. (Refer to LUBRICATION &
MAINTENANCE -
SPECIFICATIONS)
2. Thin or diluted oil. 2. Change oil and filter.
3. Low oil pressure. 3. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
4. Dirt in lash adjusters. 4. Replace as necessary.
5. Worn rocker arms. 5. Replace as necessary.
6. Worn lash adjusters 6. Replace as necessary.
7. Worn valve guides. 7. (Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE)
8. Excessive runout of valve seats
on valve faces.8. (Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE)
CONNECTING ROD NOISE 1. Insufficient oil supply. 1. (Refer to LUBRICATION &
MAINTENANCE -
SPECIFICATIONS)
2. Low oil pressure. 2. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Connecting rod journal
out-of-round.5. Service or replace crankshaft.
6. Misaligned connecting rods. 6. Replace bent connecting rods.
MAIN BEARING NOISE 1. Insufficient oil supply. 1. (Refer to LUBRICATION &
MAINTENANCE -
SPECIFICATIONS)
2. Low oil pressure. 2. Check oil pump, if Ok, check rod
and main bearings for excessive
wear.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Excessive end play. 5. Check thrust washers for wear.
6. Crankshaft journal out-of round. 6. Service or replace crankshaft.
7. Loose flywheel or torque
converter.7. Tighten to correct torque
9 - 92 ENGINE - 4.7LDR
ENGINE - 4.7L (Continued)

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) Disable the fuel system (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DESCRIPTION).
(4) Remove the ASD relay (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/AUTO SHUT DOWN
RELAY - REMOVAL).
(5) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(6)
Record the compression pressure on the 3rd revo-
lution. Continue the test for the remaining cylinders.
(7) (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:
²
Exhaust and intake valve leaks (improper seating).
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 hose.
(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.
CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
AIR ESCAPES THROUGH
THROTTLE BODYIntake valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary.
Inspect valve springs. Replace as
necessary.
AIR ESCAPES THROUGH
TAILPIPEExhaust valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary.
Inspect valve springs. Replace as
necessary.
AIR ESCAPES THROUGH
RADIATORHead gasket leaking or cracked
cylinder head or blockRemove cylinder head and inspect.
Replace defective part
MORE THAN 50% LEAKAGE
FROM ADJACENT CYLINDERSHead gasket leaking or crack in
cylinder head or block between
adjacent cylindersRemove cylinder head and inspect.
Replace gasket, head, or block as
necessary
MORE THAN 25% LEAKAGE AND
AIR ESCAPES THROUGH OIL
FILLER CAP OPENING ONLYStuck or broken piston rings;
cracked piston; worn rings and/or
cylinder wallInspect for broken rings or piston.
Measure ring gap and cylinder
diameter, taper and out-of-round.
Replace defective part as necessary
DRENGINE - 4.7L 9 - 93
ENGINE - 4.7L (Continued)

SPECIFICATIONS
SPECIFICATIONS - 4.7L ENGINE
GENERAL DESCRIPTION
DESCRIPTION SPECIFICATION
Engine Type 90É SOHC V-8 16-Valve
Displacement 4.7 Liters / 4701 cc
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
DESCRIPTION SPECIFICATION
Metric Standard
Bore Diameter 93.010 .0075
mm3.6619 0.0003
in.
Out of Round
(MAX)0.076 mm 0.003 in.
Taper (MAX) 0.051 mm 0.002 in.
PISTONS
DESCRIPTION SPECIFICATION
Metric Standard
Diameter 92.975 mm 3.6605 in.
Weight 366 grams 12.9 oz
Ring Groove
Diameter
No. 1 83.37 - 83.13
mm3.282 - 3.273 in
No. 2 82.833 - 83.033
mm3.261 - 3.310 in.
No. 3 83.88 - 84.08
mm3.302 - 3.310 in.
PISTON PINS
DESCRIPTION SPECIFICATION
Metric Standard
Clearance In
Piston0.010 - 0.019
mm0.0004 - 0.0008
in.
Diameter 24.013 - 24.016
mm0.9454 - 0.9455
in.
PISTON RINGS
DESCRIPTION SPECIFICATION
Metric Standard
Ring Gap
To p
Compression
Ring0.20 - 0.36 mm 0.0079 - 0.0142
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
To p
Compression
Ring.051 - .094 mm 0.0020 - 0.0037
in.
Second
Compression
Ring0.040 - 0.080
mm0.0016 - 0.0031
in.
Oil Ring (Steel
Ring).019 - .229 mm .0007 - .0091 in.
Ring Width
To p
Compression
Ring1.472 - 1.490
mm0.057 - 0.058 in.
Second
Compression
Ring1.472 - 1.490
mm0.057 - 0.058 in.
Oil Ring (Steel
Rails)0.445 - 0.470
mm0.017 - 0.018 in.
DRENGINE - 4.7L 9 - 99
ENGINE - 4.7L (Continued)

CONNECTING RODS
DESCRIPTION SPECIFICATION
Metric Standard
Bearing
Clearance0.015 - 0.055
mm0.0006 - 0.0022
in.
Side Clearance 0.10 - 0.35 mm 0.004 - 0.0138
in.
Piston Pin Bore
Diameter.025 - .048 mm
(Interference
Fit)0.001 - 0.0019
in.
Bearing Bore
Out of Round
(MAX)0.004 mm 0.0002 in.
Total Weight
(Less Bearing)555 grams 19.5771 ounces
CRANKSHAFT
DESCRIPTION SPECIFICATION
Metric Standard
Main Bearing
Journal
Diameter63.488 - 63.512
mm2.4996 - 2.5005
in.
Bearing
Clearance0.018 - 0.052
mm0.0008 - 0.0021
in.
Out of Round
(MAX)0.005 mm 0.0004 in.
Taper (MAX) 0.008 mm 0.0004 in.
End Play 0.052 - 0.282
mm0.0021 - 0.0112
in.
End Play (MAX) 0.282 mm 0.0112 in.
Connecting Rod
Journal
Diameter50.992 - 51.008
mm2.0076 - 2.0082
in.
Bearing
Clearance0.015 - 0.055 0.0006 - 0.0022
in.
Out of Round
(MAX)0.005 mm 0.0002 in.
Taper (MAX) 0.008 mm 0.0004 in.
CAMSHAFT
DESCRIPTION SPECIFICATION
Metric Standard
Bore Diameter 26.02 - 26.04
mm1.0245 - 1.0252
in.
Bearing Journal
Diameter25.975 - 25.995
mm1.0227 - 1.0235
in.
Bearing
Clearance0.025 - 0.065
mm0.001 - 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
DESCRIPTION SPECIFICATION
Intake
Opens (BTDC) 4.4É
Closes (ATDC) 239.1É
Duration 243.5É
Exhaust
Opens (BTDC) 240.5É
Closes (ATDC) 13.2É
Duration 253.70É
Valve Overlap 17.6É
9 - 100 ENGINE - 4.7LDR
ENGINE - 4.7L (Continued)

VALVES
DESCRIPTION SPECIFICATION
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 0.018 - 0.069 mm
(0.0008 - 0.0028 in.)
Exhaust 0.047 - 0.098 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
DESCRIPTION SPECIFICATION
Free Length (Approx)
Intake 49.0 mm (1.9291 in.)
Exhaust 49.0 mm (1.9291 in.)
Spring Force (Valve
Closed)
Intake and Exhaust 313.0 - 354.0 N @ 40.12
mm
(70.365 - 79.582 lbs. @
1.5795 in.)
Spring Force (Valve
Open)
Intake and Exhaust 776.0 - 870.0 N @ 28.88
mm
(174.451 - 195.583 lbs.
@ 1.137 in.)
Number of Coils
Intake 7.3
Exhaust 7.3
Wire Diameter
Intake and Exhaust 4.6 ý 3.67mm
(0.1811 - 0.1445 in.)
Installed Height (Spring
Seat to Bottom of
Retainer)
Nominal
Intake 40.12 mm (1.579 in.)
Exhaust 40.12 mm (1.579 in.)
DRENGINE - 4.7L 9 - 101
ENGINE - 4.7L (Continued)

CYLINDER HEAD
DESCRIPTION SPECIFICATION
Gasket Thickness
(Compressed)0.7 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
DESCRIPTION SPECIFICATION
Clearance Over
Rotors/End Face (MAX)0.095 mm (0.0038 in.)
Cover Out - of -Flat
(MAX)0.025 mm (0.001 in.)
Inner and Outer Rotor
Thickness12.02 mm (0.4731 in.)
Outer Rotor to pocket
(Diametral) clearance
(MAX).235 mm (.0093 in.)
Outer Rotor Diameter
(MIN)85.925 mm (0.400 in.)
Tip Clearance Between
Rotors (MAX)0.150 mm (0.006 in.)
OIL PRESSURE
SPECIFICATION SPECIFICATION
At Curb Idle Speed
(MIN)*48 kPa (7 psi)
@ 3000 rpm 240 - 725 kPa (35 - 105
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 58 43 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
Exhaust Manifold Heat
ShieldÐNuts8Ð72
Then loosen 45É
FlexplateÐBolts 60 45 Ð
Engine Mount Bracket to
BlockÐBolts61 45 Ð
Rear Mount to
TransmissionÐBolts46 34 Ð
Generator MountingÐBolts
M10 Bolts 54 40 Ð
M8 Bolts 28 Ð 250
Intake ManifoldÐBolts 12 Ð 105
Refer to Procedure
for
Tightening Sequence
Oil PanÐBolts 15 Ð 130
Oil PanÐDrain Plug 34 25 Ð
Oil PumpÐBolts 28 Ð 250
Oil Pump CoverÐBolts 12 Ð 105
Oil Pickup TubeÐBolt and
Nut28 Ð 250
Oil Dipstick Tube to Engine
BlockÐBolt 15 Ð 130
Oil Fill TubeÐBolts 12 Ð 105
Timing Chain GuideÐBolts 28 Ð 250
Timing Chain Tensioner
ArmÐSpecial
9 - 102 ENGINE - 4.7LDR
ENGINE - 4.7L (Continued)