Page 146 of 193

Downloaded from www.Manualslib.com manuals search engine CONDITION POSSIBLE CAUSES CORRECTION
OIL LEAKS 1. Misaligned or
deteriorated gaskets1. Replace gasket
2. Loose fastener,
broken or porous metal
part2. Tighten, repair or replace the part
3. Front or rear
crankshaft oil seal
leaking3. Replace seal
4. Leaking oil gallery
plug or cup plug4. Remove and reseal threaded plug. Replace cup style plug
5. Leaking intake 5. Replace gaskets
manifold cross-over
gaskets
EXCESSIVE OIL
CONSUMPTION
OR SPARK
PLUGS OIL
FOULED1. PCV System
malfunction1. Refer to group 25, Emission Control System for correct
operation
2. Intake manifold 2. Replace plenum
plenum pan gasket pan gasket
failure
3. Defective valve 3. Replace seals
stem seal(s)
4. Worn or broken
piston rings4. Hone cylinder bores. Install new rings
5. Scuffed pistons/
cylinder walls5. Hone cylinder bores and replace pistons as required
6. Carbon in oil control
ring groove6. Remove rings and de-carbon piston
7. Worn valve guides 6. Repair as
necessary
8. Piston rings fitted 8. Remove rings and
too tightly in grooves check ring end gap
and side clearance.
Replace if necessary
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 RPMs, 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.
DN5.9L ENGINE 9 - 145
DIAGNOSIS AND TESTING (Continued)
Page 162 of 193

Downloaded from www.Manualslib.com manuals search engine REMOVALÐ4WD
(1) Disconnect the negative cable from the battery.
(2) Raise the vehicle on a hoist.
(3) Support the transmission with a transmission
jack.
(4) Remove stud nuts holding the insulator to the
crossmember (Fig. 39).
(5) Raise rear of transmission SLIGHTLY.
(6) Remove bolts holding the insulator to the insu-
lator bracket (Fig. 39). Remove the insulator.
INSTALLATIONÐ4WD
(1) If the insulator bracket was removed, install
the bracket to the transmission (Fig. 39). Tighten the
bolts to 28 N´m (250 in. lbs.) torque.
(2) Install the bolts holding insulator to insulator
bracket. Tighten the bolts to 28 N´m (250 in. lbs.)
torque.
(3) Lower rear of transmission while aligning the
insulator studs into the mounting support bracket.Install stud nuts and tighten to 28 N´m (250 in. lbs.)
torque.
(4) Remove the transmission jack.
(5) Lower the vehicle.
(6) Connect the negative cable to the battery.
ENGINE ASSEMBLY
REMOVAL
(1) Scribe hood hinge outlines on hood. Remove the
hood.
(2) Remove the battery.
(3) Drain cooling system. Refer to COOLING SYS-
TEM.
(4) Remove the air cleaner assembly and air inlet
hose.
(5) Disconnect the radiator and heater hoses.
(6) Set fan shroud aside.
(7) Remove the vacuum lines.
(8) Remove the distributor cap and wiring.
(9) Disconnect the accelerator linkage.
(10) Remove throttle body.
(11) Perform the Fuel System Pressure release
procedure Refer to FUEL SYSTEM.
(12) Disconnect the fuel lines.
(13) Disconnect the starter wires.
(14) Disconnect the oil pressure wire.
Fig. 37 Engine Mount Insulator at FrameÐ4WD
Vehicles
1 ± NUT
2 ± ENGINE SUPPORT BRACKET
3 ± INSULATOR
4 ± NUT
5 ± THROUGH BOLT
6 ± FRAME
7 ± FRONT AXLE
Fig. 38 Rear InsulatorÐ2WD Vehicles
1 ± ENGINE SUPPORT BRACKET
2 ± THROUGH BOLT
3 ± CROSSMEMBER
4 ± INSULATOR
5 ± TRANSMISSION EXTENSION
DN5.9L ENGINE 9 - 161
REMOVAL AND INSTALLATION (Continued)
Page 163 of 193

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)