
ENGINE DIAGNOSISÐMECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES 1. High or low oil level in
crankcase.1. Check for correct oil level.
2. Thin or diluted oil. 2. Change oil to correct viscosity.
3. Low oil pressure. 3. Check engine oil level.
4. Dirt in tappets/lash adjusters. 4. Replace rocker arm/hydraulic
lash adjuster assembly.
5. Worn rocker arms. 5. Inspect oil supply to rocker arms.
6. Worn tappets/lash adjusters. 6. Install new rocker arm/hydraulic
lash adjuster assembly.
7. Worn valve guides. 7. Ream and install new valves with
oversize stems.
8. Excessive runout of valve seats
on valve faces.8. Grind valve seats and valves.
9. Missing adjuster pivot. 9. Replace rocker arm/hydraulic
lash adjuster assembly.
CONNECTING ROD NOISE 1. Insuffient oil supply. 1. Check engine oil level.
2. Low oil pressure. 2. Check engine oil level. Inspect oil
pump relief valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Excessive bearing clearance. 4. Measure bearings for correct
clearance. Repair as necessary.
5. Connecting rod journal
out-of-round.5. Replace crankshaft or grind
surface.
6. Misaligned connecting rods. 6. Replace bent connecting rods.
MAIN BEARING NOISE 1. Insufficient oil supply. 1. Check engine oil level.
2. Low oil pressure. 2. Check engine oil level. Inspect oil
pump relief valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Excessive bearing clearance. 4. Measure bearings for correct
clearance. Repair as necessary.
5. Excessive end play. 5. Check thrust bearing for wear on
flanges.
6. Crankshaft journal out-of-round
or worn.6. Replace crankshaft or grind
journals.
7. Loose flywheel or torque
converter.7. Tighten to correct torque.
OIL PRESSURE DROP 1. Low oil level. 1. Check engine oil level.
2. Faulty oil pressure sending unit. 2. Install new sending unit.
3. Low oil pressure. 3. Check sending unit and main
bearing oil clearance.
4. Clogged oil filter. 4. Install new oil filter.
5. Worn parts in oil pump. 5. Replace worn parts or pump.
6. Thin or diluted oil. 6. Change oil to correct viscosity.
7. Excessive bearing clearance. 7. Measure bearings for correct
clearance.
8. Oil pump relief valve stuck. 8. Remove valve and inspect, clean,
or replace.
9. Oil pump suction tube loose. 9. Remove oil pan and install new
tube or clean, if necessary.
10. Oil pump cover warped or
cracked.10. Install new oil pump.
9 - 12 ENGINENS
DIAGNOSIS AND TESTING (Continued)

ENGINE ASSEMBLY
REMOVAL
(1) Perform fuel pressure release procedure. Refer
to Group 14, Fuel System for procedure. Remove fuel
line to fuel rail.
(2) Disconnect battery.
(3) Remove Air cleaner and hoses.
(4) Drain cooling system. Refer to Group 7, Cooling
System for procedure.
(5) Remove upper radiator hose and remove radia-
tor fans. Refer to Group 7, Cooling System for proce-
dure.
(6) Remove lower radiator hose.
(7) Disconnect automatic transmission cooler lines
and plug, if equipped.
(8) Disconnect transmission shift linkage.
(9) Disconnect throttle body linkage.
(10) Disconnect engine wiring harness.
(11) Disconnect heater hoses.
(12) Discharge Air Conditioning System. Refer to
Group 24, Air Conditioning for procedure.
(13) Hoist vehicle and remove right inner splash
shield. Remove wheels and tires.
(14) Loosen power steering belt for pump removal.
Refer to Group 7, Cooling System for procedure.
(15) Remove axle shafts. Refer to Group 2, Suspen-
sion and Driveshafts for procedure.
(16) Disconnect exhaust pipe from manifold.
(17) Remove front and rear engine mount brackets
from the body.
(18) Remove bending braces and front engine
mount bracket. Remove transmission inspection
cover.
(19) Mark flexplate to torque converter and
remove torque converter bolts.
(20) Install front engine mount bracket.
(21) Lower vehicle.
(22) Remove power steering pump. Set pump
aside.
(23) Remove A/C lines at compressor and cap.
(24) Remove ground straps to body.
(25) Raise vehicle enough to allow engine dolly
Special Tool 6135, cradle Special Tool 6710 with
Posts Special Tool 6848 and Adaptor Special Tool
8130 to be installed under vehicle (Fig. 27).
(26) Loosen cradle posts to allow movement for
proper positioning. Locate two rear posts (right side
of engine) into the holes on the engine bedplate.
Locate the two front posts (left side of engine) on the
front engine bracket and A/C compressor bracket
(Fig. 27). Lower vehicle and position cradle mounts
until the engine is resting on mounts. Tighten
mounts to cradle frame. This will keep mounts from
moving when removing or installing engine and
transmission.(27) Lower vehicle so the weight ofONLY THE
ENGINE AND TRANSMISSIONare on the cradle.
(28) Remove engine and transmission mount bolts.
(29) Raise vehicle slowly. It may be necessary to
move the engine/transmission assembly on the cradle
to allow for removal around the body.
INSTALLATION
(1) Position engine and transmission assembly
under vehicle and slowly lower the vehicle over the
engine and transmission.
(2) Align engine and transmission mounts to
attaching points. Install mounting bolts at the right
engine and left transmission mounts. Refer to proce-
dures outlined in this section.
(3) Slowly raise vehicle enough to remove the
engine dolly and cradle Special Tools 6135 and 6710.
(4) Install axle shafts. Refer to Group 2, Suspen-
sion and Driveshafts for procedure.
(5) Install transmission and engine braces and
splash shields.
(6) Connect exhaust system to manifold. Refer to
Group 11, Exhaust System and Intake Manifold for
procedure and torque specifications.
(7) Install power steering pump. Refer to Cooling
System Group 7, Accessory Drive Section for belt ten-
sion adjustment.
(8) Install A/C compressor hoses. Refer to Group
24, Heater and Air Conditioning for procedure.
(9) Install accessory drive belts. Refer to Group 7,
Cooling System Accessory Drive Section for belt ten-
sion adjustment.
(10) Install front and rear engine mounts. Refer to
this section for procedure.
(11) Install inner splash shield. Install wheels and
tires.
(12) Connect automatic transmission cooler lines,
and shift linkage. Refer to Group 21, Transmission
for procedures.
(13) Connect fuel line and heater hoses.
(14) Install ground straps. Connect engine and
throttle body connections and harnesses. Refer to
Group 8, Electrical for procedure.
(15) Connect throttle body linkage. Refer to Group
14, Fuel System for procedure.
(16) Install radiator fans. Install radiator hoses.
Fill cooling system. Refer to Group 7, Cooling System
for filling procedure.
(17) Connect battery.
(18) Install air cleaner and hoses.
(19) Install oil filter. Fill engine crankcase with
proper oil to correct level.
(20) Start engine and run until operating temper-
ature is reached.
(21) Adjust transmission linkage, if necessary.
9 - 26 2.4L ENGINENS
REMOVAL AND INSTALLATION (Continued)

(25) Remove ground straps to body.
(26) Raise vehicle enough to allow engine dolly
Special Tool 6135 and cradle Special Tool 6710 with
post Special Tool 6848 and adaptor Special Tool 6909
to be installed under vehicle (Fig. 24).
(27) Loosen cradle engine mounts to allow move-
ment for positioning onto engine locating holes on the
engine. Lower vehicle and position cradle mounts
until the engine is resting on mounts. Tighten
mounts to cradle frame. This will keep mounts from
moving when removing or installing engine and
transmission.
(28) Lower vehicle so the weight ofONLY THE
ENGINE AND TRANSMISSIONis on the cradle.
(29) Remove right engine mount assembly and left
transmission mount through bolt. Refer to Engine
Mounts Section of this Group.
(30) Raise vehicle slowly. It may be necessary to
move the engine/transmission assembly on the cradle
to allow for removal around body flanges.
INSTALLATION
(1) Position engine and transmission assembly
under vehicle and slowly lower the vehicle over the
engine and transmission. It may be necessary to
move the engine/transmission assembly with the cra-
dle for clearance around body flanges.
(2) Align engine and transmission mounts to
attaching points. Install mounting bolts at the right
engine and left transmission mounts. Refer to proce-
dures outlined in this section.(3) Slowly raise vehicle enough to remove the
engine dolly and cradle Special Tools 6135, 6710,
6848 and 6909.
(4) Remove Special tools 6910 and install bending
braces.
(5) Lower vehicle. Install generator and wiring
harness.
(6) Connect wiring harness on the front of the
engine.
(7) Install Air Conditioning Compressor.
(8) Install power steering pump and bracket and
accessory drive belt. Refer to Group 7. Accessory
Drive Belts Section for installation procedure.
(9) Raise vehicle and install axle shafts. Refer to
Group 2, Driveshafts for procedure.
(10) Install transmission and engine mount and
bracket assemblies. Refer to Engine Mounts in this
section for procedure.
(11) Connect exhaust system to manifold. Refer to
Group 11, Exhaust System and Intake Manifold for
procedure and torque specifications.
(12) Install left and right inner splash shields.
(13) Connect automatic transmission shifter link-
age. Refer to Group 21, Transmission for procedures.
(14) Lower vehicle and connect fuel line and
heater hoses. Remove plugs from rear heater hoses
and install, if equipped.
(15) Install ground straps. Connect engine and
throttle body connections and harnesses.
(16) Connect throttle body linkage. Refer to Group
14, Fuel System for procedure.
(17) Install radiator and fan module assembly.
Install radiator hoses. Fill cooling system. Refer to
Group 7, Cooling for procedures.
(18) Install battery tray, battery and cover.
(19) Install air cleaner and hoses.
(20) Install oil filter. Fill engine crankcase with
proper oil to correct level.
(21) Start engine and run until operating temper-
ature is reached.
(22) Adjust transmission linkage, if necessary.
CYLINDER HEAD COVER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove air inlet resonator when removing left
head cover.
(3) When Removing left cylinder head cover,
remove dipstick tube.
(4) When removing right cylinder head cover
remove wiper unit. Refer to Wiper Unit Removal in
Group 8K.
(5) When removing right cylinder head cover,
remove accessory drive belt. Refer to Accessory Drive
Belt Removal in Group 7.
Fig. 24 Positioning Engine Cradle Support Post
MountsÐTypical
9 - 70 3.0L ENGINENS
REMOVAL AND INSTALLATION (Continued)

(20) Remove rear transmission mount and bracket.
(21) Remove power steering pump and bracket
assembly.
(22) Remove wiring harness and connectors from
front of engine.
(23) Remove bending braces and install tool num-
ber 6912 on engine.
(24) Remove transmission inspection cover and
mark flexplate to torque converter.
(25) Remove driveplate to torque converter bolts.
(26) Lower the vehicle.
(27) Remove ground straps to body.
(28) Raise vehicle enough to allow engine dolly
Special Tool 6135 and cradle Special Tool 6710 with
post Special Tool 6848 and adaptor Special Tool 6909
to be installed under vehicle (Fig. 28).
(29) Loosen cradle engine mounts to allow move-
ment for positioning onto engine locating holes on the
engine. Lower vehicle and position cradle mounts
until the engine is resting on mounts. Tighten
mounts to cradle frame. This will keep mounts from
moving when removing or installing engine and
transmission.
(30) Lower vehicle so the weight ofONLY THE
ENGINE AND TRANSMISSIONis on the cradle.
(31) Remove right engine mount assembly and left
transmission mount through bolt. Refer to Engine
Mounts Section of this Group.
(32) Raise vehicle slowly. It may be necessary to
move the engine/transmission assembly on the cradle
to allow for removal around body flanges.INSTALLATION
(1) Position engine and transmission assembly
under vehicle and slowly lower the vehicle over the
engine and transmission. It may be necessary to
move the engine/transmission assembly with the cra-
dle for clearance around body flanges.
(2) Align engine and transmission mounts to
attaching points. Install mounting bolts at the right
engine and left transmission mounts. Refer to proce-
dures outlined in this section.
(3) Slowly raise vehicle enough to remove the
engine dolly and cradle Special Tools 6135, 6710,
6848 and 6909.
(4) Remove Special tools 6912 and install bending
braces.
(5) Lower vehicle. Install generator and wiring
harness.
(6) Connect wiring harness on the front of the
engine.
(7) Install Air Conditioning Compressor.
(8) Install power steering pump and bracket and
accessory drive belt. Refer to Accessory drive Section
Located in group 7 for installation procedure.
(9) Raise vehicle and install axle shafts. Refer to
Group 3, Differential and Driveline for procedure.
(10) Install transmission and engine mount and
bracket assemblies. Refer to Engine Mounts section
of this Group.
(11)(AWD equipped)Install propeller shaft to
power transfer unit. Refer to Group 3, Differential
and Driveline for procedure.
(12) Connect exhaust system to manifold. Refer to
Group 11, Exhaust System and Intake Manifold for
procedure and torque specifications.
(13) Install crossmember cradle plate (Fig. 27).
(14) Install left and right inner splash shields.
(15) Connect automatic transmission shifter link-
age. Refer to Group 21, Transmission for procedures.
(16) Lower vehicle and connect fuel line and
heater hoses. Remove plugs from rear heater hoses
and install, if equipped.
(17) Install ground straps. Connect engine and
throttle body connections and harnesses.
(18) Connect throttle body linkage. Refer to Group
14, Fuel System for procedure.
(19) Install radiator and fan module assembly.
Install radiator hoses. Fill cooling system. See Group
7 for filling procedure.
(20) Install battery tray, battery and cover.
(21) Install air cleaner and hoses.
(22) Install oil filter. Fill engine crankcase with
proper oil to correct level.
(23) Start engine and run until operating temper-
ature is reached.
(24) Adjust transmission linkage, if necessary.
Fig. 28 Positioning Engine Cradle Support Post
MountsÐTypical
NS3.3/3.8L ENGINE 9 - 105
REMOVAL AND INSTALLATION (Continued)

²Turn the ignition switch on and access the ªmis-
cellaneousº screen.
²Select ªre-learn cam/crankº option and follow
directions on DRB screen.
OIL PAN
REMOVAL
(1) Drain engine oil.
(2) Remove transmission inspection cover.
(3) If equipped with air conditioning remove oil fil-
ter and adaptor. Refer to Oil Filter Adapter Removal
and Installation in this section.
(4) Remove oil pan.(5) Clean oil pan and all gasket surfaces.
Fig. 40 Timing Belt System
Fig. 41 Camshaft Timing Marks
Fig. 42 Right Inner Splash Shield
NS/GSENGINE 9 - 17
REMOVAL AND INSTALLATION (Continued)

2.5L VM DIESEL
INDEX
page page
GENERAL INFORMATION
ENGINE IDENTIFICATION................ 41
GENERAL SPECIFICATION............... 40
DESCRIPTION AND OPERATION
LUBRICATION SYSTEM.................. 41
DIAGNOSIS AND TESTING
ENGINE DIAGNOSISÐMECHANICAL....... 44
ENGINE DIAGNOSISÐPERFORMANCE..... 43
HYDRAULIC TAPPETS................... 47
SERVICE PROCEDURES
CHANGING ENGINE OIL AND FILTER....... 47
CHECKING OIL LEVEL................... 47
CRANKSHAFT END PLAY................ 50
FITTING PISTON RING.................. 50
TIMING PROCEDURE................... 49
VALVE AND SEAT REFACING............. 49
REMOVAL AND INSTALLATION
CAMSHAFT........................... 62
CAMSHAFT BEARINGS.................. 63
CRANKSHAFT MAIN BEARINGS........... 63
CRANKSHAFTÐREMOVAL............... 72
CYLINDER HEAD....................... 55
CYLINDER HEAD COVER................ 54
CYLINDER LINER...................... 72
ENGINE ASSEMBLY..................... 53
ENGINE MOUNTÐFRONT................ 51
ENGINE MOUNTÐREAR................. 52
ENGINE MOUNTÐRIGHT................ 51
HYDRAULIC TAPPETS................... 60
INJECTION PUMP...................... 61
MOUNTÐLEFT SIDE.................... 51
OIL FILTER ADAPTER AND OIL COOLER.... 68
OILPAN .............................. 66OIL PUMP............................ 67
OIL PUMP PRESSURE RELIEF VALVE...... 67
PISTONS AND CONNECTING ROD......... 68
REAR CRANKSHAFT OIL SEAL............ 72
ROCKER ARMS AND PUSH RODS......... 54
TIMING GEAR COVER................... 61
TIMING GEAR COVER OIL SEAL........... 61
VACUUM PUMP........................ 68
VALVE SPRINGSÐCYLINDER HEAD NOT
REMOVED.......................... 55
VALVES AND VALVE SPRINGSÐHEAD OFF . . 60
VIBRATION DAMPER.................... 61
DISASSEMBLY AND ASSEMBLY
HYDRAULIC TAPPETS................... 73
CLEANING AND INSPECTION
CRANKSHAFT......................... 77
CRANKSHAFT MAIN BEARING............ 77
CYLINDER HEAD....................... 75
CYLINDER HEAD COVERS............... 74
CYLINDER LINER...................... 78
HYDRAULIC TAPPETS................... 76
OILPAN .............................. 78
OIL PUMP............................ 76
PISTON AND CONNECTING ROD.......... 76
ROCKER ARMS AND PUSH RODS......... 74
TIMING GEAR COVER................... 75
VALVES AND VALVE SPRINGS............ 76
SPECIFICATIONS
2.5L VM DIESEL........................ 78
TORQUE............................. 80
SPECIAL TOOLS
2.5L VM DIESEL........................ 81
GENERAL INFORMATION
GENERAL SPECIFICATION
Type ........................425CLIEE (36B)
Displacement...................2.5L (2499 cc)
Bore.............................92.00 mm
Stroke............................94.00 mm
Compression Ratio....................20.95:1
Vacuum at Idle..........600mm/Hg (23.6 In/Hg)
Thermostat Opening................80ÉC62ÉC
Generator Rating............Bosch 50/120 Amp
Cooling System Capacity..............9.5Liter
Power Steering Capacity.............0.75 LiterType ........................425CLIEE (36B)
Engine Oil Capacity.....6.5Liters With Oil Filter
Change
Timing System . Pushrod Operated Overhead valves,
With Gear-Driven Camshaft.
Air Intake........................DryFilter
Fuel Feed...........Vacuum Pump Incorporated
in Injection Pump.
Fuel System.............Indirect Fuel Injection
(Precombustion Chamber)
Combustion Cycle....................4Stroke
Cooling System..................Water Cooled
Injection Pump.......Rotary Pump Electronically
Controlled.
9 - 40 ENGINENS/GS

DIAGNOSIS AND TESTING
ENGINE DIAGNOSISÐPERFORMANCE
CONDITION POSSIBLE CAUSES CORRECTION
ENGINE WILL NOT
CRANK OR CRANKS
SLOWLY1. Starting motor operating, but not cranking the
engine.1. Remove the starter motor. Check for broken
flywheel teeth or a broken starter motor spring.
2. Crankshaft rotation restricted. 2. Rotate the engine to check for rotational
resistance.
3. Starting circuit connections loose or corroded. 3. Clean and tighten connections.
4. Neutral safety or starter relay inoperative. 4. Check starter relay supply voltage and proper
operation of neutral safety switch (if equipped).
Replace defective parts.
5. Battery charge low. 5. Check Battery voltage. Replace battery if a
charge cannot be held.
6. No voltage to starter solenoid. 6. Check voltage to solenoid. If necessary, replace
the solenoid.
7. Solenoid or starter motor inoperative. 7. Replace starter motor.
ENGINE CRANKS, BUT
WILL NOT START, NO
SMOKE1. No fuel in supply tank. 1. Fill fuel supply.
2. Electrical fuel shutdown solenoid not operating. 2. Check for loose wires and verify that the fuel
shutdown solenoid is functioning. Check for fault
codes in the ECU.
3. Fuel injection system defective: Cranking speed
sensor. Loose connection between ECU and
harness. No power supply to the ECU. Loose
connection between injection pump and harness.3. Check for fault codes at ECU. Refer to Group 14,
Fuel System for repairs procedures.
4. Air intake or exhaust plugged. 4. Remove the obstruction.
5. Fuel filter plugged. 5. Drain fuel/water separator and replace fuel filter.
6. Excessive fuel inlet restriction. 6. Check for restriction. Correct cause.
7. Injection pump not getting fuel or fuel is aerated. 7. Check fuel flow/bleed fuel system.
8. One or more injectors worn or not operating
properly.8. Check/replace bad or improperly operating
injectors.
9. Camshaft out of time. 9. Check/correct timing chain sprocket alignment.
ENGINE HARD TO
START, OR WILL NOT
START, SMOKE FROM
EXHAUST1. Incorrect starting procedure. 1. The fuel shutoff solenoid control must be in the
run position. Ensure the proper procedure is being
used.
2. Cranking speed to slow. 2. Check the battery, starter motor and look for
loose or corroded wiring connections.
3. Cylinder head heater plugs defective. 3. Verify system is working. Verify connection
between heater plug relay and ECU. Repair/replace
inoperative parts.
4. Insufficient intake air 4. Inspect or replace air filter and check for
obstruction in air supply.
5. Air in fuel system or the fuel supply is
inadequate.5. Check the fuel flow through the filter and bleed
system. Locate and eliminate the air source.
6. Contaminated fuel. 6. Verify by operating the engine with clean fuel
from a temporary tank. Check for the presence of
gasoline. Drain and flush fuel supply tank. Replace
fuel/water separator filter.
7. Fuel screen plugged. 7. Check fuel screen.
8. One or more injectors worn or not operating
properly.8. Check/replace improperly operating injectors.
9. Injector pump out of time. 9. Check pump timing. Refer to Group 14, Fuel
System for procedure.
10. Engine compression low. 10. Check compression to identify the problem.
11. Fuel injection system defective. 11. Vacuum modulator defective causing EGR to
open in cold condition. Check for fault codes in the
ECU.
NS/GSENGINE 9 - 43

ENGINE DIAGNOSISÐMECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
LUBRICATING OIL PRESSURE
LOW1. Low oil level. 1a. Check and fill with clean engine
oil.
1b. Check for severe external oil
leaks that could reduce the
pressure.
2. Oil viscosity thin, diluted, or
wrong specification.2. Verify the correct oil is being
used. Check for oil dilution.
3. Improperly operating pressure
switch/gauge3. Verify the pressure switch is
functioning correctly. If not, replace
switch/gauge.
4. Relief valve stuck open. 4. Check/replace valve.
5. Plugged oil filter. 5. Change oil filter. Oil filter change
interval may need to be revised.
6. Oil cooler was replaced, shipping
plugs left in cooler.6. Check/removed shipping plugs.
7. Worn oil pump. 7. Check/replace oil pump.
8. Suction tube loose or seal
leaking.8. Check and replace seal.
9. Worn bearing or wrong bearing
installed.9. Inspect and replace connecting
rod or main bearings. check and
replace piston cooling oil jet.
10. Oil jets under piston loose or
bad fit.10. Check oil jets position.
LUBRICATING OIL LOSS 1. External oil leaks. 1. Visually inspect for oil leaks.
Repair as required.
2. Crankcase being overfilled. 2. Verify that the correct dipstick is
being used.
3. Incorrect oil specification or
viscosity.3a. Make sure the correct oil is
being used.
3b. Look for reduced viscosity from
dilution with fuel.
3c. Review/reduce the oil change
intervals.
4. Oil cooler leak. 4. Check and replace the oil cooler.
5. High blow-by forcing oil out the
breather.5. Check the breather tube area for
signs of oil loss.
9 - 44 ENGINENS/GS
DIAGNOSIS AND TESTING (Continued)