1999 DODGE DURANGO DIAGNOSIS

Downloaded from www.Manualslib.com manuals search engine ENGINE
TABLE OF CONTENTS
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4.7L ENGINE.............................. 1
5.2L ENGINE............................. 865.9L ENGINE............................ 135
4.7L ENGINE
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
ENGINE.................................2
ENGINE LUBRICATION SYSTEM..............3
CYLINDER BLOCK.........................5
CRANKSHAFT............................5
PISTON AND CONNECTING ROD.............5
CYLINDER HEAD..........................5
VALVE GUIDES...........................5
VALVES.................................5
VALVE STEM SEAL........................5
VALVE SPRING...........................6
HYDRAULIC LASH ADJUSTER...............6
TIMING DRIVE SYSTEM....................6
CAMSHAFT..............................6
ROCKER ARM............................6
CYLINDER HEAD COVER...................6
OILPAN.................................7
STRUCTURAL DUST COVER................7
INTAKE MANIFOLD........................7
EXHAUST MANIFOLD......................7
DIAGNOSIS AND TESTING
ENGINE DIAGNOSISÐINTRODUCTION.........7
SERVICE DIAGNOSISÐPERFORMANCE.......8
SERVICE DIAGNOSISÐMECHANICAL.........10
SERVICE DIAGNOSISÐLUBRICATION.........11
INTAKE MANIFOLD LEAKAGE DIAGNOSIS.....11
CYLINDER COMPRESSION PRESSURE TEST . . 11
CYLINDER HEAD GASKET FAILURE
DIAGNOSIS...........................12
CYLINDER COMBUSTION PRESSURE
LEAKAGE TEST........................12
ENGINE OIL LEAK INSPECTION.............13
REAR SEAL AREA LEAKSÐINSPECTION......14
HYDRAULIC LASH ADJUSTER NOISE
DIAGNOSIS...........................14
CHECKING ENGINE OIL PRESSURE..........15SERVICE PROCEDURES
FORM-IN-PLACE GASKETS.................15
ENGINE OIL.............................16
REPAIR DAMAGED OR WORN THREADS......17
CYLINDER BOREÐHONING................18
HYDROSTATIC LOCK.....................18
VALVE SERVICE.........................19
ENGINE TIMINGÐVERIFICATION............19
TIMING CHAINÐMEASURING WEAR.........22
PISTONSÐFITTING.......................22
PISTON RINGSÐFITTING..................24
CONNECTING ROD BEARINGSÐFITTING.....25
CRANKSHAFT MAIN BEARINGS.............27
REMOVAL AND INSTALLATION
ENGINE MOUNTSÐLEFT AND RIGHT.........28
ENGINE MOUNTÐREAR...................29
STRUCTURAL COVER.....................30
ENGINE ASSEMBLY.......................31
INTAKE MANIFOLD.......................35
EXHAUST MANIFOLDS....................36
CYLINDER HEAD COVER..................38
ROCKER ARMS..........................40
CYLINDER HEADS........................41
VALVE SPRINGS AND SEALS...............46
HYDRAULIC LASH ADJUSTER..............46
CRANKSHAFT DAMPER...................47
TIMING CHAIN COVER....................48
TIMING CHAIN AND SPROCKETS............49
IDLER SHAFTÐTIMING DRIVE..............55
CAMSHAFTSÐIN VEHICLE.................56
CRANKSHAFT MAIN BEARINGS.............61
OIL PAN 4X2 VEHICLE.....................61
OIL PAN 4X4 VEHICLE.....................64
PISTON AND CONNECTING ROD............65
CRANKSHAFT...........................67
FLEXPLATE.............................69
DNENGINE 9 - 1

Downloaded from www.Manualslib.com manuals search engine 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.
STRUCTURAL DUST COVER
DESCRIPTION
The structural dust cover is made of die cast alu-
minum and joins the lower half of the transmission
bell housing to the engine bedplate.
OPERATION
The structural cover provides additional power-
train stiffness and reduces noise and vibration.
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.
EXHAUST MANIFOLD
DESCRIPTION
The exhaust manifolds are log style with a pat-
ented flow enhancing design to maximize perfor-mance. The exhaust manifolds are made of high
silicon molybdenum cast iron. A perforated core
graphite exhaust manifold gasket is used to improve
sealing to the cylinder head. The exhaust manifolds
are covered by a three layer laminated heat shield
for thermal protection and noise reduction. The heat
shields are fastened with a torque prevailing nut
that is backed off slightly to allow for the thermal
expansion of the exhaust manifold.
DIAGNOSIS AND TESTING
ENGINE DIAGNOSISÐINTRODUCTION
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 the Service DiagnosisÐPerformance chart
and the Service DiagnosisÐMechanical chart for pos-
sible causes and corrections of malfunctions. Refer to
Group 14, Fuel System 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.
²Cylinder Combustion Pressure Leakage Test.
²Engine Cylinder Head Gasket Failure Diagnosis.
²Intake Manifold Leakage Diagnosis.
DN4.7L ENGINE 9 - 7
DESCRIPTION AND OPERATION (Continued)

Downloaded from www.Manualslib.com manuals search engine SERVICE DIAGNOSISÐPERFORMANCE
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 Group 8A, Battery/
Starter/ Charging System
Diagnostics.
4. Moisture on ignition wires and
distributor cap.4. Wipe wires and cap clean and
dry.
5. Faulty ignition cables. 5. Replace as necessary.
6. Faulty coil or control unit. 6. Refer to Group 8D, Ignition
System.
7. Incorrect spark plug gap. 7. Refer to Group 8D, Ignition
System.
8. Incorrect ignition timing. 8. Refer to Group 8D, Ignition
System.
9. Dirt or water in fuel system. 9. Clean system and replace fuel
filter.
10. Faulty fuel pump, relay or
wiring.10. Refer to Group 14, Fuel System.
ENGINE STALLS OR ROUGH IDLE 1. Idle speed set to low. 1. Refer to Group 14, Fuel System.
2. Idle mixture to lean or to rich. 2. Refer to Group 14, Fuel System.
3. Vacuum leak. 3. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
4. Worn or burned distributor rotor. 4. Replace distributor rotor.
5. Incorrect ignition wiring. 5. Install correct wiring.
6. Faulty coil. 6. Refer to Group 8D, Ignition
System.
7. EGR valve leaking. 7. Refer to Group 25, Emissions
Control System.
8. Incorrect cam timing. 8. Refer to Valve Timing in this
section.
9 - 8 4.7L ENGINEDN
DIAGNOSIS AND TESTING (Continued)

Downloaded from www.Manualslib.com manuals search engine CONDITION POSSIBLE CAUSE CORRECTION
ENGINE LOSS OF POWER 1. Incorrect ignition timing. 1. Refer to Group 8D, Ignition
System.
2. Worn or burned distributor rotor. 2. Replace distributor rotor.
3. Worn distributor shaft. 3. Refer to Group 8D, Ignition
System.
4. Dirty or incorrectly gapped spark
plugs.4. Refer to Group 8D, Ignition
System.
5. Dirt or water in fuel system. 5. Clean system and replace fuel
filter.
6. Faulty fuel pump. 6. Refer to Group 14, Fuel System.
7. Blown cylinder head gasket. 7. Replace cylinder head gasket.
8. Low compression. 8. Test compression, repair as
necessary.
9. Burned, warped or pitted valves. 9. Replace as necessary.
10. Plugged or restricted exhaust
system.10. Inspect and replace as
necessary.
11. Faulty ignition cables. 11. Replace as necessary.
12. Faulty coil. 12. Refer to Group 8D, Ignition
System.
13. Incorrect cam timing. 13. Refer to Valve Timing in this
section.
ENGINE MISSES ON
ACCELERATION1. Spark plugs dirty or incorrectly
gapped.1. Refer to Group 8D, Ignition
System.
2. Incorrect ignition timing. 2. Refer to Group 8D, Ignition
System.
3. Dirt in fuel system. 3. Clean fuel system.
4. Burned, warped or pitted valves. 4. Replcae as necessary.
5. Faulty coil. 5. Refer to Group 8D, Ignition
System.
6. Incorrect cam timing. 6. Refer to Valve Timing in this
section.
ENGINE MISSES AT HIGH SPEED 1. Spark plugs dirty or incorrectly
gapped.1. Refer to Group 8D, Ignition
System.
2. Worn Distributor Shaft. 2. Refer to Group 8D, Ignition
System.
3. Worn or burned distributor rotor. 3. Replace distributor rotor.
4. Faulty coil. 4. Refer to Group 8D, Ignition
System.
5. Incorrect ignition timing. 5. Refer to Group 8D, Ignition
System.
6. Dirt or water in fuel system. 6. Clean system and replace fuel
filter.
7. Incorrect cam timing. 7. Refer to Valve Timing in this
section.
DN4.7L ENGINE 9 - 9
DIAGNOSIS AND TESTING (Continued)

Downloaded from www.Manualslib.com manuals search engine SERVICE DIAGNOSISÐMECHANICAL
CONDITION POSSIBLE CAUSES CORRECTIONS
NOISY VALVES 1. High or low oil level in
crankcase.1. Refer to Group 0, Lubrication and
Maintenance.
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. Clean lash adjusters.
5. Bent push rods. 5. Replace as necessary.
6. Worn rocker arms. 6. Replace as necessary.
7. Worn tappets 7. Replace as necessary.
8. Worn valve guides. 8. Refer to Valve Service in this
section.
9. Excessive runout of valve seats
on valve faces.9. Service valves and valve seats.
Refer to Valve Service in this
section.
CONNECTING ROD NOISE 1. Insufficient oil supply. 1. Refer to Group 0, Lubrication and
maintenance.
2. Low oil pressure. 2. Refer to Group 0, Lubrication and
maintenance.
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 Group 0, Lubrication and
maintenance.
2. Low oil pressure. 2. Refer to Group 0, Lubrication and
maintenance.
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Replace as necessary.
5. Excessive end play. 5. Check No. 3 main bearing for
wear on flanges.
6. Crankshaft journal out-of round. 6. Service or replace crankshaft.
7. Loose flywheel or torque
converter.7. Tighten to correct torque
9 - 10 4.7L ENGINEDN
DIAGNOSIS AND TESTING (Continued)

Downloaded from www.Manualslib.com manuals search engine SERVICE DIAGNOSISÐLUBRICATION
CONDITION POSSIBLE CAUSES CORRECTION
OIL LEAKS 1. Gaskets and O-Rings. 1.
(a) Misaligned or damaged. (a) Replace as necessary.
(b) Loose fasteners, broken or
porous metal parts.(b) Tighten fasteners, Repair or
replace metal parts.
2. Crankshaft rear seal 2. Replace as necessary.
3. Crankshaft seal flange.
Scratched, nicked or grooved.3. Polish or replace crankshaft.
4. Oil pan flange cracked. 4. Replace oil pan.
5. Timing chain cover seal,
damaged or misaligned.5. Replace seal.
6. Scratched or damaged vibration
damper hub.6. Polish or replace damper.
OIL PRESSURE DROP 1. Low oil level. 1. Check and correct oil level.
2. Faulty oil pressure sending unit. 2. Replace sending unit.
3. Low oil pressure. 3. Check pump and bearing
clearance.
4. Clogged oil filter. 4. Replace oil filter.
5. Worn oil pump. 5. Replace as necessary.
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. Clean or replace relief valve.
9. Oil pump suction tube loose or
damaged.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.
3. Incorrect ring size installed. 3. Replace rings.
4. Worn valve guides. 4. Ream guides and replace valves.
5. Leaking intake gasket. 5. Replace intake gaskets.
6. Leaking valve guide seals. 6. Replace valve guide seals.
INTAKE MANIFOLD LEAKAGE DIAGNOSIS
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.
CYLINDER COMPRESSION PRESSURE TEST
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.
DN4.7L ENGINE 9 - 11
DIAGNOSIS AND TESTING (Continued)

Downloaded from www.Manualslib.com manuals search engine 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 Group 14,
Fuel System for the correct procedure)
(5) Disconnect the ignition coil.
(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.
Refer to Engine Specifications for the correct
engine compression pressures.
CYLINDER HEAD GASKET FAILURE DIAGNOSIS
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
²Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
²Possible 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 in this
section. An engine cylinder head gasket leaking
between adjacent cylinders will result in approxi-
mately 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.
CYLINDER COMBUSTION PRESSURE LEAKAGE
TEST
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).
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.
(6)
Calibrate the tester according to the manufacturer's
instructions. The shop air source for testing should main-
tain 483 kPa (70 psi) minimum, 1,379 kPa (200 psi) maxi-
mum and 552 kPa (80 psi) recommended.
(7) Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
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 the Cylinder Combustion Pressure Leak-
age Test Diagnosis chart.
9 - 12 4.7L ENGINEDN
DIAGNOSIS AND TESTING (Continued)

Downloaded from www.Manualslib.com manuals search engine 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
AIR ESCAPES THROUGH
TAILPIPEExhaust valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or 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
ENGINE OIL LEAK INSPECTION
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.
(4)If the oil leak source is not positively
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.
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
DN4.7L ENGINE 9 - 13
DIAGNOSIS AND TESTING (Continued)