fuel DODGE DURANGO 1999 1.G Owner's Manual

Downloaded from www.Manualslib.com manuals search engine (2) Position the cylinder head cover onto the gas-
ket. Tighten the bolts to 11 N´m (95 in. lbs.) torque.
(3) Install closed crankcase ventilation system and
evaporation control system.
(4) Install the air inlet hose.
(5) Connect the negative cable to the battery.
ROCKER ARMS AND PUSH RODS
REMOVAL
(1) Remove cylinder head cover and gasket. Refer
to Cylinder Head Cover in this section for correct
procedure.
(2) Remove the rocker arm bolts and pivots (Fig.
44). Place them on a bench in the same order as
removed.
(3) Remove the push rods and place them on a
bench in the same order as removed.
INSTALLATION
(1) Rotate the crankshaft until the ªV8º mark lines
up with the TDC mark on the timing chain case
cover. This mark is located 147É ATDC from the No.1
firing position.
(2) Install the push rods in the same order as
removed.
(3) Install rocker arm and pivot assemblies in the
same order as removed. Tighten the rocker arm bolts
to 28 N´m (21 ft. lbs.) torque.
CAUTION: DO NOT rotate or crank the engine dur-
ing or immediately after rocker arm installation.
Allow the hydraulic roller tappets adequate time to
bleed down (about 5 minutes).
(4) Install cylinder head cover.
VALVE SPRING AND STEM SEAL
REPLACEMENT-IN VEHICLE
(1) Remove the air cleaner.
(2) Remove cylinder head covers and spark plugs.(3) Remove coil wire from distributor and secure to
good ground to prevent engine from starting.
(4) Using suitable socket and flex handle at crank-
shaft retaining bolt, turn engine so the No.1 piston is
at TDC on the compression stroke.
(5) Remove rocker arms.
(6) With air hose attached to an adapter installed
in No.1 spark plug hole, apply 620-689 kPa (90-100
psi) air pressure.
(7) Using Valve Spring Compressor Tool
MD-998772A with adaptor 6716A, compress valve
spring and remove retainer valve locks and valve
spring.
(8) Install seals on the exhaust valve stem and
position down against valve guides.
(9) The intake valve stem seals should be pushed
firmly and squarely over the valve guide using the
valve stem as a guide. DO NOT force seal against top
of guide. When installing the valve retainer locks,
compress the spring only enough to install the locks.
(10) Follow the same procedure on the remaining 7
cylinders using the firing sequence 1-8-4-3-6-5-7-2.
Make sure piston in cylinder is at TDC on the valve
spring that is being removed.
(11) Remove adapter from the No.1 spark plug
hole and install spark plugs.
(12) Install rocker arms.
(13) Install covers and coil wire to distributor.
(14) Install air cleaner.
(15) Road test vehicle.
CYLINDER HEAD
REMOVAL
(1) Disconnect the battery negative cable.
(2) Drain cooling system Refer to COOLING SYS-
TEM.
(3) Remove the intake manifold-to-generator
bracket support rod. Remove the generator.
(4) Remove closed crankcase ventilation system.
(5) Disconnect the evaporation control system.
(6) Remove the air cleaner assembly and air inlet
hose.
(7) Perform fuel system pressure release proce-
dure. Refer to FUEL SYSTEM.
(8) Disconnect the fuel supply line.
(9) Disconnect accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(10) Remove distributor cap and wires.
(11) Disconnect the coil wires.
(12) Disconnect heat indicator sending unit wire.
(13) Disconnect heater hoses and bypass hose.
(14) Remove cylinder head covers and gaskets.
Fig. 44 Rocker Arms
1 ± ROCKER ARMS
2 ± CYLINDER HEAD
DN5.2L ENGINE 9 - 107
REMOVAL AND INSTALLATION (Continued)

Downloaded from www.Manualslib.com manuals search engine (15) Remove intake manifold and throttle body as
an assembly. Discard the flange side gaskets and the
front and rear cross-over gaskets.
(16) Remove exhaust manifolds.
(17) Remove rocker arm assemblies and push rods.
Identify to ensure installation in original locations.
(18) Remove the head bolts from each cylinder
head and remove cylinder heads. Discard the cylin-
der head gasket.
(19) Remove spark plugs.
INSTALLATION
(1) Position the new cylinder head gaskets onto
the cylinder block.
(2) Position the cylinder heads onto head gaskets
and cylinder block.
(3) Starting at top center, tighten all cylinder head
bolts, in sequence, to 68 N´m (50 ft. lbs.) torque (Fig.
45). Repeat procedure, tighten all cylinder head bolts
to 143 N´m (105 ft. lbs.) torque. Repeat procedure to
confirm that all bolts are at 143 N´m (105 ft. lbs.)
torque.
CAUTION: When tightening the rocker arm bolts,
make sure the piston in that cylinder is NOT at
TDC. Contact between the valves and piston could
occur.
(4) Install push rods and rocker arm assemblies in
their original position. Tighten the bolts to 28 N´m
(21 ft. lbs.) torque.
(5) Install the intake manifold and throttle body
assembly.
(6) Install exhaust manifolds. Tighten the bolts
and nuts to 34 N´m (25 ft. lbs.) torque.
(7) Adjust spark plugs to specifications. Refer to
IGNITION SYSTEM. Install the plugs and tighten to
41 N´m (30 ft. lbs.) torque.
(8) Install coil wires.
(9) Connect heat indicator sending unit wire.(10) Connect the heater hoses and bypass hose.
(11) Install distributor cap and wires.
(12) Connect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(13) Install the fuel supply line.
(14) Install the generator and drive belt. Tighten
generator mounting bolt to 41 N´m (30 ft. lbs.)
torque.
(15) Install the intake manifold-to-generator
bracket support rod. Tighten the bolts.
(16) Place the cylinder head cover gaskets in posi-
tion and install cylinder head covers. Tighten the
bolts to 11 N´m (95 in. lbs.) torque.
(17) Install closed crankcase ventilation system.
(18) Connect the evaporation control system.
(19) Install the air cleaner assembly and air inlet
hose.
(20) Install the heat shields. Tighten the bolts to
41 N´m (30 ft. lbs.) torque.
(21) Fill cooling system.
(22) Connect the battery negative cable.
VALVES AND VALVE SPRINGS
REMOVAL
(1) Remove the cylinder head. Refer to Cylinder
Head in this section for correct procedure.
(2) Compress valve springs using Valve Spring
Compressor Tool MD- 998772A and adapter 6716A.
(3) Remove valve retaining locks, valve spring
retainers, valve stem seals and valve springs.
(4) Before removing valves, remove any burrs from
valve stem lock grooves to prevent damage to the
valve guides. Identify valves to ensure installation in
original location.
INSTALLATION
(1) Clean valves thoroughly. Discard burned,
warped and cracked valves.
(2) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
(3) Measure valve stems for wear. If wear exceeds
0.051 mm (0.002 inch), replace the valve.
(4) Coat valve stems with lubrication oil and insert
them in cylinder head.
(5) If valves or seats are reground, check valve
stem height. If valve is too long, replace cylinder
head.
(6) Install new seals on all valve guides. Install
valve springs and valve retainers.
(7) Compress valve springs with Valve Spring
Compressor Tool MD-998772A and adapter 6716A,
install locks and release tool. If valves and/or seats
are ground, measure the installed height of springs.
Make sure the measurement is taken from bottom ofFig. 45 Cylinder Head Bolt Tightening Sequence
9 - 108 5.2L ENGINEDN
REMOVAL AND INSTALLATION (Continued)

Downloaded from www.Manualslib.com manuals search engine (7) Position the fan shroud and install the bolts.
Tighten the retainer bolts to 11 N´m (95 in. lbs.)
torque.
(8) Connect the negative cable to the battery.
TIMING CHAIN COVER
(1) Disconnect the negative cable from the battery.
(2) Drain cooling system (refer to Group 7, Cooling
System).
(3) Remove the serpentine belt (refer to Group 7,
Cooling System).
(4) Remove water pump (refer to Group 7, Cooling
System).
(5) Remove power steering pump (refer to Group
19, Steering).
(6) Remove vibration damper.
(7) Remove fuel lines (refer to Group 14, Fuel Sys-
tem).
(8) Loosen oil pan bolts and remove the front bolt
at each side.
(9) Remove the cover bolts.
(10) Remove chain case cover and gasket using
extreme caution to avoid damaging oil pan gasket.
(11) Place a suitable tool behind the lips of the oil
seal to pry the oil seal outward. Be careful not to
damage the crankshaft seal surface of cover (Fig. 48).
INSTALLATION
(1) Be sure mating surfaces of chain case cover
and cylinder block are clean and free from burrs.
(2) The water pump mounting surface must be
cleaned.
(3) Using a new cover gasket, carefully install
chain case cover to avoid damaging oil pan gasket.
Use a small amount of Mopar Silicone Rubber Adhe-
sive Sealant, or equivalent, at the joint between tim-
ing chain cover gasket and the oil pan gasket. Finger
tighten the timing chain cover bolts at this time.
(4) Place the smaller diameter of the oil seal over
Front Oil Seal Installation Tool 6635 (Fig. 49). Seat
the oil seal in the groove of the tool.
(5) Position the seal and tool onto the crankshaft
(Fig. 50).(6) Tighten the 4 lower chain case cover bolts to
13N´m (10 ft.lbs.) to prevent the cover from tipping
during seal installation.
(7) Using the vibration damper bolt, tighten the
bolt to draw the seal into position on the crankshaft
(Fig. 51).
(8) Loosen the 4 bolts tightened in step 4 to allow
realignment of front cover assembly.
Fig. 48 Removal of Front Crankshaft Oil Seal
Fig. 49 Placing Oil Seal on Installation Tool 6635
1 ± CRANKSHAFT FRONT OIL SEAL
2 ± INSTALL THIS END INTO SPECIAL TOOL 6635
Fig. 50 Position Tool and Seal onto Crankshaft
1 ± SPECIAL TOOL 6635
2 ± OIL SEAL
3 ± TIMING CHAIN COVER
9 - 110 5.2L ENGINEDN
REMOVAL AND INSTALLATION (Continued)

Downloaded from www.Manualslib.com manuals search engine After the distributor has been installed, its rota-
tional position must be set using theSET SYNC
mode of the DRB scan tool. Refer to Checking Dis-
tributor Position following the Distributor Installa-
tion section in Group 8D, Ignition system.
Do not attempt to adjust ignition timing by
rotating the distributor. It has no effect on igni-
tion timing. Adjusting distributor position will
effect fuel synchronization only.
OIL PAN
REMOVAL
2WD
(1) Disconnect the negative cable from the battery.
(2) Remove air cleaner assembly.
(3) Remove engine oil dipstick.
(4) Disconnect distributor cap and position away
from cowl.
(5) Remove the fan shroud. Refer to COOLING
SYSTEM.
(6) Disconnect throttle valve cable from throttle
body and mounting bracket (Fig. 62A).
(7) Raise vehicle.
(8) Drain engine oil.
(9) Remove exhaust pipe from exhaust manifolds.
(10) Remove engine mount insulator through bolts.
(11) Raise engine by way of oil pan using a block
of wood between the jack and oil pan.
(12) When engine is high enough, place mount
through bolts in the engine mount attaching points
on the frame brackets.
(13) Lower engine so bottom of engine mounts rest
on the replacement bolts placed in the engine mount
frame brackets.
(14) Remove transmission to engine braces.
(15) Remove starter. Refer to STARTING SYS-
TEMS.(16) Remove transmission torque converter inspec-
tion cover.
(17) Disconnect rear support cushion from cross-
member.
(18) Raise rear of transmission away from cross-
member.
(19) Remove oil pan and one-piece gasket.
4WD
(1) Disconnect the negative cable from the battery.
(2) Remove engine oil dipstick.
(3) Raise vehicle.
(4) Drain engine oil.
(5) Remove front driving axle. Refer to DIFFER-
ENTIAL and DRIVELINE.
(6) Remove both engine mount support brackets.
(7) Remove transmission torque converter inspec-
tion cover.
(8) Remove oil pan and one-piece gasket.
INSTALLATION
2WD
(1) Fabricate 4 alignment dowels from 5/16x11/2
inch bolts. Cut the head off the bolts and cut a slot
into the top of the dowel. This will allow easier
installation and removal with a screwdriver (Fig. 63).
Fig. 62 Position of Oil Pump Shaft Slot
1 ± DISTRIBUTOR DRIVE
Fig. 62A Throttle Valve Cable Removal/Installation
1 ± TRANSMISSION THROTTLE VALVE CABLE BRACKET
2 ± AIR INLET DUCT
3 ± TRANSMISSION THROTTLE VALVE CABLE
DN5.2L ENGINE 9 - 115
REMOVAL AND INSTALLATION (Continued)
2000 DN Service Manual
Publication No. 81-370-0016
TSB 26-12-99 December, 1999

Downloaded from www.Manualslib.com manuals search engine DESCRIPTION AND OPERATION
ENGINE
DESCRIPTION
The 5.9 Liter (360 CID) eight-cylinder engine is a
V-Type lightweight, single cam, overhead valve
engine with hydraulic roller tappets. This engine is
designed for unleaded fuel.
The engine lubrication system consists of a rotor
type oil pump and a full flow oil filter.
The cylinders are numbered from front to rear; 1,
3, 5, 7 on the left bank and 2, 4, 6, 8 on the right
bank. The firing order is 1-8-4-3-6-5-7-2 (Fig. 1).
The engine serial number is stamped into a
machined pad located on the left, front corner of the
cylinder block. When component part replacement is
necessary, use the engine type and serial number for
reference (Fig. 2).
ENGINE LUBRICATION SYSTEM
DESCRIPTION
A gear-type positive displacement pump (Fig. 3) is
mounted at the underside of the rear main bearing
cap. The pump uses a pick-up tube and screen
assembly to gather engine oil from the oil pan.
OPERATION
The pump draws oil through the screen and inlet
tube from the sump at the rear of the oil pan. The oil
is driven between the drive and idler gears and
pump body, then forced through the outlet to the
block. An oil gallery in the block channels the oil to
the inlet side of the full flow oil filter. After passing
through the filter element, the oil passes from the
center outlet of the filter through an oil gallery that
channels the oil up to the main gallery, which
extends the entire length on the right side of the
block. The oil then goes down to the No. 1 main bear-
ing, back up to the left side of the block, and into the
oil gallery on the left side of the engine.
Galleries extend downward from the main oil gal-
lery to the upper shell of each main bearing. The
crankshaft is drilled internally to pass oil from the
main bearing journals to the connecting rod journals.
Each connecting rod bearing has half a hole in it, oil
passes through the hole when the rods rotate and the
hole lines up, oil is then thrown off as the rod
rotates. This oil throwoff lubricates the camshaft
lobes, distributor drive gear, cylinder walls, and pis-
ton pins.
Fig. 1 Firing Order
Fig. 2 Engine Identification Number
Fig. 3 Positive Displacement Oil PumpÐTypical
1 ± INNER ROTOR AND SHAFT
2 ± BODY
3 ± DISTRIBUTOR DRIVESHAFT (REFERENCE)
4 ± COTTER PIN
5 ± RETAINER CAP
6 ± SPRING
7 ± RELIEF VALVE
8 ± LARGE CHAMFERED EDGE
9 ± BOLT
10 ± COVER
11 ± OUTER ROTOR
9 - 136 5.9L ENGINEDN

Downloaded from www.Manualslib.com manuals search engine EXHAUST MANIFOLD
DESCRIPTION
The exhaust manifolds are constructed of cast iron
and are LOG type with balanced flow (Fig. 5). One
exhaust manifold is attached to each cylinder head.
OPERATION
The exhaust manifolds collect the engine exhaust
exiting the combustion chambers, then channels the
exhaust gases to the exhaust pipes attached to the
manifolds.
INTAKE MANIFOLD
DESCRIPTION
The aluminum intake manifold (Fig. 6) is a single
plane design with equal length runners and uses a
separate plenum, therefore the manifold does have a
plenum gasket. It also uses separate flange gaskets
and front and rear cross-over gaskets. Extreme caremust be used when sealing the gaskets to ensure
that excess sealant does not enter the intake runners
causing a restriction. Whenever the intake manifold
is removed inspect the plenum pan for evidence of
excess oil buildup, this condition indicates that the
plenum pan gasket is leaking.
OPERATION
The intake manifold, meters and delivers air to the
combustion chambers allowing the fuel delivered by
the fuel injectors to ignite, thus producing power.
1 ± OIL DEFLECTOR TAB
2 ± BOLT
3 ± ROCKER ARM PIVOT
4 ± ROCKER ARM
5 ± DRIP OILING FOR VALVE TIP
6 ± CYLINDER HEAD BOSS
7 ± TO MAIN BEARINGS
8 ± TO CAMSHAFT BEARINGS
9 ± ROCKER ARM
10 ± HOLLOW PUSH ROD
11 ± TAPPET
12 ± TO CONNECTING ROD BEARINGS
13 ± OIL INTAKE14 ± OIL PUMP
15 ± OIL FILTER
16 ± CRANKSHAFT
17 ± FROM OIL PUMP
18 ± OIL TO FILTER
19 ± OIL FROM FILTER TO SYSTEM
20 ± PASSAGE TO CAMSHAFT REAR BEARING
21 ± RIGHT OIL GALLERY
22 ± PLUG
23 ± OIL PASSAGE FOR OIL PRESSURE INDICATOR LIGHT
24 ± OIL SUPPLY VIA HOLLOW PUSH ROD SUPPLY IS FROM
OIL GALLERY METERED THROUGH HYDRAULIC TAPPET
25 ± OIL SUPPLY FROM HOLLOW PUSH ROD
Fig. 5 Exhaust ManifoldsÐV-8 Gas Engines Typical
1 ± EXHAUST MANIFOLD (LEFT)
2 ± BOLTS & WASHERS
3 ± NUTS & WASHERS
4 ± EXHAUST MANIFOLD (RIGHT)
5 ± BOLTS & WASHERS
Fig. 6 Intake Manifold and Throttle BodyÐV-8 Gas
Engines Typical
1 ± FUEL RAIL ASSEMBLY
2 ± FUEL RAIL MOUNTING BOLTS
3 ± FUEL RAIL CONNECTING HOSES
DN5.9L ENGINE 9 - 139
DESCRIPTION AND OPERATION (Continued)

Downloaded from www.Manualslib.com manuals search engine CYLINDER HEAD COVER GASKET
DESCRIPTION
The cylinder head cover gasket is a steel-backed
silicone gasket, designed for long life usage (Fig. 7).
OPERATION
The steel-backed silicone gasket is designed to seal
the cylinder head cover for long periods of time
through extensive heat and cold, without failure. The
gasket is designed to be reusable.
CYLINDER HEAD
DESCRIPTION
The cast iron cylinder heads (Fig. 8) are mounted
to the cylinder block using ten bolts. The spark plugs
are located in the peak of the wedge between the
valves.
OPERATION
The cylinder head closes the combustion chamber
allowing the pistons to compress the air fuel mixture
to the correct ratio for ignition. The valves located in
the cylinder head open and close to either allow clean
air into the combustion chamber or to allow the
exhaust gases out, depending on the stroke of the
engine.
VALVES AND VALVE SPRINGS
DESCRIPTION
Both the intake and exhaust valves are made of
steel. The intake valve is 48.768 mm (1.92 inches) in
diameter and the exhaust valve is 41.148 mm (1.62
inches) in diameter and has a 2.032 mm (0.080 inch)
wafer interia welded to the tip for durability. These
valves are not splayed.
ENGINE OIL PAN
DESCRIPTION
The stamped steel engine oil pan is located at the
bottom of the engine, and contains a drain plug for
draining the engine oil.
OPERATION
The oil pan holds the engine oil and seals and pro-
tects the engine lower components from contami-
nates.
CRANKSHAFT OIL SEALS
DESCRIPTION
The crankshaft rear seal is a two piece viton seal.
The crankshaft front seal is a one piece viton seal
with a steel housing. The front seal is located in the
engine front cover. One part of the two piece rear
seal is located in a slot in the number five (5) crank-
shaft main bore, the second part of the two piece seal
is located in the number five (5) main bearing cap.
OPERATION
The crankshaft seals prevent oil from leaking from
around the crankshaft, either from the rear of the
engine or from the engine front cover.
PISTON AND CONNECTING ROD
DESCRIPTION
The pistons are made of aluminum and have three
ring grooves, the top two grooves are for the compres-
sion rings and the bottom groove is for the oil control
ring. The connecting rods are forged steel and are
coined prior to heat treat. The piston pins are press
fit.
Fig. 7 Cylinder Head Cover Gasket V-8 Gas Engines
1 ± CYLINDER HEAD COVER GASKET
Fig. 8 Cylinder Head AssemblyÐV-8 Gas Engines
1 ± EXHAUST VALVE
2 ± SPARK PLUGS
3 ± EXHAUST VALVES
4 ± SPARK PLUGS
5 ± EXHAUST VALVE
6 ± INTAKE VALVES
7 ± INTAKE VALVES
9 - 140 5.9L ENGINEDN
DESCRIPTION AND OPERATION (Continued)

Downloaded from www.Manualslib.com manuals search engine CRANKSHAFT MAIN BEARINGS
DESCRIPTION
Main bearings are located in the cylinder block.
One half of the main bearing is located in the crank-
shaft main bore the other half of the matching bear-
ing is located in the main bearing cap (Fig. 9). There
are five main bearings. Number three main bearing
is flanged, this flange controls crankshaft thrust.
OPERATION
The main bearings encircle the crankshaft main
bearing journals, this aligns the crankshaft to the
centerline of the engine and allows the crankshaft to
turn without wobbling or shaking therefore eliminat-
ing vibration. The main bearings are available in
standard and undersizes.
CRANKSHAFT
DESCRIPTION
The crankshaft is of a cast nodular steel splayed
type design, with five main bearing journals. The
crankshaft is located at the bottom of the engine
block and is held in place with five main bearing
caps. The number 3 counterweight is the location for
journal size identification (Fig. 10).
OPERATION
The crankshaft transfers force generated by com-
bustion within the cylinder bores to the flywheel or
flexplate.
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
mechanical (e.g., a strange noise), or performance
(e.g., engine idles rough and stalls).
Refer to the Service DiagnosisÐMechanical Chart
and the Service DiagnosisÐPerformance Chart, for
possible causes and corrections of malfunctions. Refer
to 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:
²Cylinder Compression Pressure Test
²Cylinder Combustion Pressure Leakage Test
²Cylinder Head Gasket Failure Diagnosis
²Intake Manifold Leakage Diagnosis
²Lash Adjuster (Tappet) Noise Diagnosis
²Engine Oil Leak Inspection
Fig. 9 Main Bearing Orientation
Fig. 10 Crankshaft with Journal Size Identification
DN5.9L ENGINE 9 - 141
DESCRIPTION AND OPERATION (Continued)

Downloaded from www.Manualslib.com manuals search engine SERVICE DIAGNOSISÐGASOLINE ENGINES
PERFORMANCE DIAGNOSIS CHARTÐGASOLINE ENGINES
CONDITION POSSIBLE CAUSES CORRECTION
ENGINE WILL
NOT CRANK1. Weak or dead battery 1. Charge/Replace Battery. Refer to Group 8A,
Battery, for correct procedures. Check charging
system. Refer to Group 8C, Charging Systems, for
correct procedures.
2. Corroded or loose battery
connections2. Clean/tighten suspect battery/starter connections
3. Faulty starter or related circuit(s) 3. Check starting system. Refer to Group 8B,
Starting Systems, for correct diagnostics/procedures
4. Seized accessory drive
component4. Remove accessory drive belt and attempt to start
engine. If engine starts, repair/replace seized
component.
5. Engine internal mechanical
failure or hydro-static lock5. Refer to Group 9, Engine, for correct diagnostics/
procedures
ENGINE CRANKS
BUT WILL NOT
START1. No spark 1. Check for spark. Refer to Group 8D, Ignition
System, for correct procedures.
2. No fuel 2. Perform fuel pressure test, and if necessary,
inspect fuel injector(s) and driver circuits. Refer to
Group 14, Fuel System, for correct procedures.
3. Low or no engine compression 3. Perform cylinder compression pressure test. Refer
to Group 9, Engine, for correct procedures.
ENGINE LOSS OF
POWER1. Worn or burned distributor rotor 1. Install new distributor rotor
2. Worn distributor shaft 2. Remove and repair distributor (Refer to Group 8D,
Ignition System
3. Worn or incorrect gapped spark
plugs3. Clean plugs and set gap. (Refer to Group 8D,
Ignition System)
4. Dirt or water in fuel system 4. Clean system and replace fuel filter
5. Faulty fuel pump 5. Install new fuel pump
6. Incorrect valve timing 6. Correct valve timing
7. Blown cylinder head gasket 7. Install new cylinder head gasket
8. Low compression 8. Test cylinder compression
9. Burned, warped, or pitted valves 9. Install/Reface valves as necessary
10. Plugged or restricted exhaust
system10. Install new parts as necessary
11. Faulty ignition cables 11. Replace any cracked or shorted cables
12. Faulty ignition coil 12. Test and replace, as necessary (Refer to Group
8D, Ignition System)
ENGINE STALLS
OR ROUGH IDLE1. Carbon build-up on throttle plate 1. Remove throttle body and de-carbon. (Refer to
Group 14 for correct procedures)
2. Engine idle speed too low 2. Check Idle Air Control circuit. (Refer to Group 14,
Fuel System)
9 - 142 5.9L ENGINEDN
DIAGNOSIS AND TESTING (Continued)

Downloaded from www.Manualslib.com manuals search engine CONDITION POSSIBLE CAUSES CORRECTION
3. Worn or incorrectly gapped spark
plugs3. Replace or clean and re-gap spark plugs (Refer to
group 8D, Ignition System)
4. Worn or burned distributor rotor 4. Install new distributor rotor
5. Spark plug cables defective or
crossed5. Check for correct firing order or replace spark plug
cables. (Refer to Group 8D, Ignition System for
correct procedures.)
6. Faulty coil 6. Test and replace, if necessary (Refer to group 8D,
Ignition System)
7. Intake manifold vacuum leak 7. Inspect intake manifold gasket and vacuum hoses.
Replace if necessary
8. EGR valve leaking or stuck open 8. Test and replace, if necessary (Refer to group 25,
Emission Control Systems)
ENGINE MISSES
ON
ACCELERATION1. Worn or incorrectly gapped spark
plugs1. Replace spark plugs or clean and set gap. (Refer
to group 8D, Ignition System)
2. Spark plug cables defective or
crossed2. Replace or rewire secondary ignition cables. Refer
to Group 8D, Ignition System
3. Dirt in fuel system 3. Clean fuel system
4. Burned, warped or pitted valves 4. Install new valves
5. Faulty coil 5. Test and replace as necessary (refer to group 8D,
Ignition System)
MECHANICAL DIAGNOSIS CHARTÐGASOLINE ENGINES
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES/
LIFTERS1. High or low oil level
in crankcase1. Check for correct oil level. Adjust oil level by draining or adding
as needed
2. Thin or diluted oil 2. Change oil (Refer to Engine Oil Service in this group)
3. Low oil pressure 3. Check engine oil level. If ok, Perform oil pressure test. Refer to
this group for engine oil pressure test/specifications
4. Dirt in tappets/lash
adjusters4. Clean/replace hydraulic tappets/lash adjusters
5. Bent push rod(s) 5. Install new push rods
6. Worn rocker arms 6. Inspect oil supply to rocker arms and replace worn arms as
needed
7. Worn tappets/lash
adjusters7. Install new hydraulic tappets/lash adjusters
8. Worn valve guides 8. Inspect all valve guides and replace as necessary
9. Excessive runout of
valve seats or valve
faces9. Grind valves and seats
DN5.9L ENGINE 9 - 143
DIAGNOSIS AND TESTING (Continued)