air condition DODGE DURANGO 1998 1.G Owner's Manual

Downloaded from www.Manualslib.com manuals search engine HYDRAULIC TAPPETS
Before disassembling any part of the engine to cor-
rect tappet noise, check the oil pressure. If vehicle
has no oil pressure gauge, install a reliable gauge at
the pressure sending-unit. The pressure should be
between 207-552 kPa (30-80 psi) at 3,000 RPM.
Check the oil level after the engine reaches normal
operating temperature. Allow 5 minutes to stabilize
oil level, check dipstick. The oil level in the pan
should never be above the FULL mark or below the
ADD OIL mark on dipstick. Either of these two con-
ditions could be responsible for noisy tappets.
OIL LEVEL
HIGH
If oil level is above the FULL mark, it is possible
for the connecting rods to dip into the oil. With the
engine running, this condition could create foam in
the oil pan. Foam in oil pan would be fed to the
hydraulic tappets by the oil pump causing them to
lose length and allow valves to seat noisily.
LOW
Low oil level may allow oil pump to take in air.
When air is fed to the tappets, they lose length,
which allows valves to seat noisily. Any leaks on
intake side of oil pump through which air can be
drawn will create the same tappet action. Check the
lubrication system from the intake strainer to the
pump cover, including the relief valve retainer cap.
When tappet noise is due to aeration, it may be
intermittent or constant, and usually more than one
tappet will be noisy. When oil level and leaks have
been corrected, operate the engine at fast idle. Run
engine for a sufficient time to allow all of the air
inside the tappets to be bled out.
TAPPET NOISE DIAGNOSIS
(1) To determine source of tappet noise, operate
engine at idle with cylinder head covers removed.
(2) Feel each valve spring or rocker arm to detect
noisy tappet. The noisy tappet will cause the affected
spring and/or rocker arm to vibrate or feel rough in
operation.
NOTE: Worn valve guides or cocked springs are
sometimes mistaken for noisy tappets. If such is
the case, noise may be dampened by applying side
thrust on the valve spring. If noise is not apprecia-
bly reduced, it can be assumed the noise is in the
tappet. Inspect the rocker arm push rod sockets
and push rod ends for wear.
(3) Valve tappet noise ranges from light noise to a
heavy click. A light noise is usually caused by exces-
sive leak-down around the unit plunger, or by theplunger partially sticking in the tappet body cylinder.
The tappet should be replaced. A heavy click is
caused by a tappet check valve not seating, or by for-
eign particles wedged between the plunger and the
tappet body. This will cause the plunger to stick in
the down position. This heavy click will be accompa-
nied by excessive clearance between the valve stem
and rocker arm as valve closes. In either case, tappet
assembly should be removed for inspection and clean-
ing.
(4) The valve train generates a noise very much
like a light tappet noise during normal operation.
Care must be taken to ensure that tappets are mak-
ing the noise. If more than one tappet seems to be
noisy, it's probably not the tappets.
LEAK-DOWN TEST
After cleaning and inspection, test each tappet for
specified leak-down rate tolerance to ensure zero-lash
operation (Fig. 11).
Swing the weighted arm of the hydraulic valve tap-
pet tester away from the ram of the Universal Leak-
Down Tester.
(1) Place a 7.925-7.950 mm (0.312-0.313 inch)
diameter ball bearing on the plunger cap of the tap-
pet.
(2) Lift the ram and position the tappet (with the
ball bearing) inside the tester cup.
(3) Lower the ram, then adjust the nose of the ram
until it contacts the ball bearing. DO NOT tighten
the hex nut on the ram.
(4) Fill the tester cup with hydraulic valve tappet
test oil until the tappet is completely submerged.
(5) Swing the weighted arm onto the push rod and
pump the tappet plunger up and down to remove air.
When the air bubbles cease, swing the weighted arm
away and allow the plunger to rise to the normal
position.
(6) Adjust the nose of the ram to align the pointer
with the SET mark on the scale of the tester and
tighten the hex nut.
(7) Slowly swing the weighted arm onto the push
rod.
(8) Rotate the cup by turning the handle at the
base of the tester clockwise one revolution every 2
seconds.
(9) Observe the leak-down time interval from the
instant the pointer aligns with the START mark on
the scale until the pointer aligns with the 0.125
mark. A normally functioning tappet will require
20-110 seconds to leak-down. Discard tappets with
leak-down time interval not within this specification.
ENGINE OIL PRESSURE
(1) Remove oil pressure sending unit.
9 - 148 5.9L ENGINEDN
DIAGNOSIS AND TESTING (Continued)

Downloaded from www.Manualslib.com manuals search engine Damaged or worn threads can be repaired. Essen-
tially, this repair consists of:
²Drilling out worn or damaged threads.
²Tapping the hole with a special Heli-Coil Tap, or
equivalent.
²Installing an insert into the tapped hole to bring
the hole back to its original thread size.
CYLINDER BOREÐHONING
Before honing, stuff plenty of clean shop towels
under the bores and over the crankshaft to keep
abrasive materials from entering the crankshaft
area.
(1) Used carefully, the Cylinder Bore Sizing Hone
C-823, equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round, as well as removing light
scuffing, scoring and scratches. Usually, a few strokes
will clean up a bore and maintain the required lim-
its.
CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). about 20-60
strokes, depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Using honing
oil C-3501-3880, or a light honing oil, available from
major oil distributors.
CAUTION: DO NOT use engine or transmission oil,
mineral spirits, or kerosene.
(3) Honing should be done by moving the hone up
and down fast enough to get a crosshatch pattern.The hone marks should INTERSECT at 50É to 60É
for proper seating of rings (Fig. 17).
(4) A controlled hone motor speed between 200 and
300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50É to 60É
angle. Faster up and down strokes increase the cross-
hatch angle.
(5) After honing, it is necessary that the block be
cleaned to remove all traces of abrasive. Use a brush
to wash parts with a solution of hot water and deter-
gent. Dry parts thoroughly. Use a clean, white, lint-
free cloth to check that the bore is clean. Oil the
bores after cleaning to prevent rusting.
HYDROSTATIC LOCK
When an engine is suspected of hydrostatic lock
(regardless of what caused the problem), follow the
steps below.
(1) Perform the Fuel Pressure Release Procedure
(refer to Group 14, Fuel System).
(2) Disconnect the battery negative cable.
(3) Inspect air cleaner, induction system and
intake manifold to ensure system is dry and clear of
foreign material.
(4) Place a shop towel around the spark plugs to
catch any fluid that may possibly be under pressure
in the cylinder head. Remove the plugs from the
engine.
CAUTION: DO NOT use the starter motor to rotate
the crankshaft. Severe damage could occur.
(5) With all spark plugs removed, rotate the crank-
shaft using a breaker bar and socket.
Fig. 16 Oil Filter Sealing SurfaceÐTypical
1 ± SEALING SURFACE
2 ± RUBBER GASKET
3 ± OIL FILTER
Fig. 17 Cylinder Bore Crosshatch Pattern
1 ± CROSSHATCH PATTERN
2 ± INTERSECT ANGLE
9 - 152 5.9L ENGINEDN
SERVICE PROCEDURES (Continued)

Downloaded from www.Manualslib.com manuals search engine (15) Discharge the air conditioning system, if
equipped. Refer to HEATING and AIR CONDITION-
ING.
(16) Disconnect the air conditioning hoses.
(17) Disconnect the power steering hoses, if
equipped.
(18) Remove starter motor. Refer to STARTING
SYSTEMS.
(19) Remove the generator.
(20) Raise and support the vehicle on a hoist.
(21) Disconnect exhaust pipe at manifold.
(22) Remove Transmission. Refer to TRANSMIS-
SIONS.
CAUTION: DO NOT lift the engine by the intake
manifold.
(23) Install an engine lifting fixture.
(24)2WD VEHICLESÐRemove engine front
mount bolts.
(25)4WD VEHICLESÐThe engine and front
driving axle (engine/axle/transmission) are connectedthrough insulators and support brackets. Separate
the engine as follows:
²LEFT SIDEÐRemove 2 bolts attaching
(engine/pinion nose/transmission) bracket to trans-
mission bell housing. Remove 2 bracket to pinion
nose adaptor bolts. Separate engine from insulator by
removing upper nut washer assembly and bolt from
engine support bracket.
²RIGHT SIDEÐRemove 2 bracket to axle (dis-
connect housing) bolts and a bracket to bell housing
bolt. Separate engine from insulator by removing
upper nut washer assembly and bolt from engine
support bracket.
(26) Lower the vehicle.
(27) Install engine assembly on engine repair
stand.
INSTALLATION
(1) Remove engine from the repair stand and posi-
tion in the engine compartment.
(2) Install an engine support fixture.
(3) Raise and support the vehicle on a hoist.
(4) Install the engine front mounts.
(5) Refer to Group, 21 Transmissions for transmis-
sion installation
(6) Install the inspection plate.
(7) Remove transmission support.
(8) Install exhaust pipe to manifold.
(9) Lower the vehicle.
(10) Remove engine lifting fixture.
(11) Install the generator.
(12) Install starter motor.
(13) Connect power steering hoses, if equipped.
(14) Connect air conditioning hoses.
(15) Evacuate and charge the air conditioning sys-
tem, if equipped.
(16) Using a new gasket, install throttle body.
Tighten the throttle body bolts to 23 N´m (200 in.
lbs.) torque.
(17) Connect the accelerator linkage.
(18) Connect the starter wires.
(19) Connect the oil pressure wire.
(20) Install the distributor cap and wiring.
(21) Connect the vacuum lines.
(22) Connect the fuel lines.
(23) Install the radiator. Connect the radiator
hoses and heater hoses.
(24) Install fan shroud in position.
(25) Fill cooling system.
(26) Install the air cleaner assembly and air inlet
hose.
(27) Install the battery.
(28) Warm engine and adjust.
(29) Install hood and line up with the scribe
marks.
(30) Road test vehicle.
Fig. 39 Rear InsulatorÐ4WD Vehicles
1 ± AUTOMATIC TRANSMISSION
2 ± INSULATOR BRACKET
3 ± INSULATOR
4 ± CROSSMEMBER
9 - 162 5.9L ENGINEDN
REMOVAL AND INSTALLATION (Continued)

Downloaded from www.Manualslib.com manuals search engine INTAKE MANIFOLD
REMOVAL
(1) Disconnect the battery negative cable.
(2) Drain the cooling system. Refer to COOLING
SYSTEM.
(3) Remove the A/C compressor. Refer to HEAT-
ING and AIR CONDITIONING.
(4) Remove the generator. Refer to CHARGING
SYSTEM.
(5) Remove the accessory drive bracket.
(6) Remove the air cleaner assembly and air inlet
hose.
(7) Perform the fuel pressure release procedure.
Refer to FUEL SYSTEM.
(8) Disconnect the fuel supply line from the fuel
rail. Refer to FUEL SYSTEM.
(9) Disconnect the accelerator linkage and, if so
equipped, the speed control and transmission kick-
down cables.
(10) Remove the distributor cap and wires.
(11) Disconnect the coil wires.
(12) Disconnect the coolant temperature sending
unit wire.
(13) Disconnect the heater hoses and bypass hose.
(14) Remove the closed crankcase ventilation and
evaporation control systems.
(15) Remove intake manifold bolts.
(16) Lift the intake manifold and throttle body out
of the engine compartment as an assembly.
(17) Remove and discard the flange side gaskets
and the front and rear cross-over gaskets.
(18) Remove the throttle body bolts and lift the
throttle body off the intake manifold (Fig. 40). Dis-
card the throttle body gasket.
INSTALLATION
(1) If the plenum pan was removed, position pan
gasket and pan.
(2) Install plenum pan retaining bolts. (Fig. 41).
(3) Tighten plenum pan mounting bolts as follows:
²Step 1. Tighten bolts to 5.4 N´m (24 in. lbs.)
²Step 2. Tighten bolts to 9.5 N´m (84 in. lbs.)
²Step 3. Check all bolts are at 9.5 N´m (84 in.
lbs.)
(4) Using a new gasket, install the throttle body
onto the intake manifold. Tighten the bolts to 23 N´m
(200 in. lbs.) torque.
(5) Apply a bead of Mopar Silicone Rubber Adhe-
sive Sealant, or equivalent, to the four corner joints.
The sealant bead height should be slightly higher
than the cross-over gaskets, approximately 5 mm (0.2
in). An excessive amount of sealant is not required to
ensure a leak proof seal, and an excessive amount of
sealant may reduce the effectiveness of the flange
gasket.
(6) Install the front and rear cross-over gaskets
onto the engine (Fig. 42).
(7) Install the flange gaskets. Ensure that the ver-
tical port alignment tab is resting on the deck face of
the block. Also the horizontal alignment tabs must be
in position with the mating cylinder head gasket tabs
(Fig. 43). The words MANIFOLD SIDE should be vis-
ible on the center of each flange gasket.
(8) Carefully lower intake manifold into position
on the cylinder block and cylinder heads. long studs
at the front and rear of the manifold will help to
align the intake manifold. After intake manifold is in
Fig. 40 Throttle Body Assembly
1 ± FUEL RAIL ASSEMBLY
2 ± FUEL RAIL MOUNTING BOLTS
3 ± FUEL RAIL CONNECTING HOSES
Fig. 41 Plenum Pan Bolt Tightening Sequence
DN5.9L ENGINE 9 - 163
REMOVAL AND INSTALLATION (Continued)

Downloaded from www.Manualslib.com manuals search engine ASSEMBLE
(1) Install pump rotors and shaft, using new parts
as required.
(2) Position the oil pump cover onto the pump
body. Tighten cover bolts to 11 N´m (95 in. lbs.)
torque.
(3) Install the relief valve and spring. Insert the
cotter pin.
(4) Tap on a new retainer cap.
(5) Prime oil pump before installation by filling
rotor cavity with engine oil.
CLEANING AND INSPECTION
CYLINDER HEAD COVER
CLEANING
Clean cylinder head cover gasket surface.
Clean head rail, if necessary.
INSPECTION
Inspect cover for distortion and straighten, if nec-
essary.
Check the gasket for use in head cover installation.
If damaged, use a new gasket.
CYLINDER HEAD ASSEMBLY
CLEANING
Clean all surfaces of cylinder block and cylinder
heads.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
INSPECTION
Inspect all surfaces with a straightedge if there is
any reason to suspect leakage. If out-of-flatness
exceeds 0.00075 mm/mm (0.00075 inch/inch) times
the span length in inches in any direction, either
replace head or lightly machine the head surface.
FOR EXAMPLE:A 305 mm (12 inch) span is
0.102 mm (0.004 inch) out-of-flat. The allowable out-
of-flat is 305 X 0.00075 (12 X 0.00075) equals 0.23
mm (0.009 inch). This amount of out-of-flat is accept-
able.
The cylinder head surface finish should be
1.78-3.00 microns (70-125 microinches).
PISTON AND CONNECTING ROD ASSEMBLY
INSPECTION
Check the crankshaft connecting rod journal for
excessive wear, taper and scoring.
Check the cylinder block bore for out-of-round,
taper, scoring and scuffing.Check the pistons for taper and elliptical shape
before they are fitted into the cylinder bore (Fig. 83).
OIL PAN
CLEANING
Clean the block and pan gasket surfaces.
Trim or remove excess sealant film in the rear
main cap oil pan gasket groove.DO NOT remove
the sealant inside the rear main cap slots.
If present, trim excess sealant from inside the
engine.
Clean oil pan in solvent and wipe dry with a clean
cloth.
Clean oil screen and pipe thoroughly in clean sol-
vent. Inspect condition of screen.
INSPECTION
Inspect oil drain plug and plug hole for stripped or
damaged threads. Repair as necessary.
Inspect oil pan mounting flange for bends or distor-
tion. Straighten flange, if necessary.
OIL PUMP
INSPECTION
Mating surface of the oil pump cover should be
smooth. Replace pump assembly if cover is scratched
or grooved.
Lay a straightedge across the pump cover surface
(Fig. 84). If a 0.038 mm (0.0015 inch) feeler gauge
can be inserted between cover and straightedge,
pump assembly should be replaced.
Fig. 83 Piston Measurements
1 ± 49.53 mm
(1.95 IN.)
9 - 182 5.9L ENGINEDN
DISASSEMBLY AND ASSEMBLY (Continued)