ENGINE MOUNT RUBBER INSULATORS
Insulator location on (right side) is adjustable to
allow right/left drive train adjustment in relation to
drive shaft assembly length.
Check and reposition right engine mount insulator.
See Adjustments in this section. Adjust drive train
position, if required, for the following conditions:
a. Drive shaft distress. See Group 2, Suspension
and Driveshafts.
b. Any front end structural damage (after repair).
c. Insulator replacement.
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) Remove battery cover, battery and battery tray,
with integral vacuum reservoir, from vehicle.
(5) Block off heater hoses to rear heater assembly,
if equipped.
(6) Drain cooling system. Refer to Group 7, Cooling
System for procedure.
(7) Disconnect heater hoses.
(8) Remove fan module and radiator. Refer to
Group 7 Cooling System for procedure.
(9) Disconnect transmission shift linkage.
(10) Disconnect throttle body linkage and vacuum
hoses from throttle body.
(11) Remove accessory drive belts. Refer to Group
7, Accessory Drive Belts located in Cooling System
for procedure.
(12) Remove air conditioning compressor from
engine and set it aside.
(13) Disconnect generator wiring harness and
remove generator.
(14) Hoist vehicle and remove right and left inner
splash shields.
(15) Remove crossmember cradle plate (Fig. 27).
(16) Remove axle shafts. Refer to Group 3, Differ-
ential and Driveline for procedure.
(17)(AWD equipped)Mark orientation and sepa-
rate propeller shaft from power transfer unit. Refer
to Group 3, Differential and Driveline for procedure.
(18) Disconnect exhaust pipe from manifold.
(19) Remove front engine mount and bracket as an
assembly.
Fig. 25 Engine MountingÐLeft
Fig. 26 Engine MountingÐRear
Fig. 27 Crossmember Cradle Plate
9 - 104 3.3/3.8L ENGINENS
REMOVAL AND INSTALLATION (Continued)
CRANKSHAFT DAMPER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Raise vehicle on hoist.
(3) Remove right wheel and inner splash shield.
(4) Remove drive belt. Refer to Group 7, Cooling
System for procedure.
(5) Remove crankshaft pulley (Fig. 29).
INSTALLATION
(1) Install crankshaft pulley (Fig. 30).
(2) Install drive belt. Refer to Cooling System
Group 7 for installation procedure.
(3) Install inner splash shield and wheel.
(4) Connect negative cable to battery.
ROCKER ARMS AND SHAFT ASSEMBLY
REMOVAL
(1) Remove upper intake manifold assembly. Refer
to Group 11, Intake and Exhaust Manifolds.(2) Disconnect spark plug wires by pulling on the
boot straight out in line with plug.
(3) Disconnect closed ventilation system.
(4) Remove cylinder head cover and gasket.
(5) Remove four rocker shaft bolts and retainers.
(6) Remove rocker arms and shaft assembly.
(7) If rocker arm assemblies are disassembled for
cleaning or replacement. Assemble rocker arms in
their original position. Refer to (Fig. 31) for rocker
arm for positioning on the shaft.
INSTALLATION
(1) Install rocker arm and shaft assemblies with
the stamped steel retainers in the four positions,
tighten to 28 N´m (250 in. lbs.) (Fig. 31).
CAUTION: THE ROCKER ARM SHAFT SHOULD BE
TORQUED DOWN SLOWLY, STARTING WITH THE
CENTER BOLTS. ALLOW 20 MINUTES TAPPET
BLEED DOWN TIME AFTER INSTALLATION OF THE
ROCKER SHAFTS BEFORE ENGINE OPERATION.
(2) Clean cylinder head cover gasket surface.
Inspect cover for distortion and straighten if neces-
sary.
(3) Clean head rail if necessary. Install a new gas-
ket and tighten cylinder head cover fasteners to 12
N´m (105 in. lbs.).
(4) Install closed crankcase ventilation system.
(5) Install spark plug wires.
(6) Install upper intake manifold assembly. Refer
to Group 11, Exhaust Systems and Intake Manifolds.
VALVE STEM SEALS OR SPRINGS, CYLINDER
HEAD NOT REMOVED
(1) Perform fuel system pressure release procedure
before attempting any repairs.
(2) Disconnect negative cable from battery.
(3) Remove air cleaner cover and hose assembly.
Fig. 29 Crankshaft DamperÐRemoval
Fig. 30 Crankshaft DamperÐInstallation
Fig. 31 Rocker Arm Location Left Bank
9 - 106 3.3/3.8L ENGINENS
REMOVAL AND INSTALLATION (Continued)
SPARK PLUG TUBE
(1) Remove valve cover. Refer to procedure out-
lined in this section.
(2) Using locking pliers remove the tube from the
cylinder head (Fig. 11). Discard old tube.
(3) Clean area around spark plug with Mopart
parts cleaner or equivalent.
(4) Apply MopartStud and Bearing Mount or
equivalent to a new tube approximately 1 mm from
theendina3mmwide area.
(5) Install sealer end of tube into the cylinder
head. Then carefully install the tube using a hard-
wood block and mallet until the tube is seated into
the bottom of the bore.
(6) Install valve cover. Refer to procedure outlined
in this section.
SPARK PLUG TUBE SEALS
The spark plug tube seals are located in the cylin-
der head cover (Fig. 12). These seals are pressed into
the cylinder head cover to seal the outside perimeterof the spark plug tubes. If these seals show signs of
hardness and/or cracking they should be replaced.
CAMSHAFT
NOTE: TO REMOVE CAMSHAFT THE CYLINDER
HEAD MUST BE REMOVED.
REMOVAL
(1) Perform fuel system pressure release procedure
before attempting any repairs.Refer to Group 14,
Fuel System
(2) Remove the cylinder head cover. Refer to proce-
dure outlined in this section.
(3) Mark rocker arm shaft assemblies so that they
are installed in their original positions.
(4) Remove rocker arm shaft bolts. Refer to proce-
dure outlined in this section.
(5) Remove timing belt, timing belt tensioner, and
camshaft sprocket. Refer to timing belt service out-
lined in this section.
(6) Remove inner timing belt cover.
(7) Remove cylinder head. Refer to procedure out-
lined in this section.
(8) Remove camshaft sensor and camshaft target
magnet.
(9) Remove camshaft from the rear of cylinder
head.
INSPECT CYLINDER HEAD FOR THE FOLLOWING:
NOTE:
²Check oil feed holes for blockage.
²Inspect cylinder head camshaft bearings for
wear, Refer to Cylinder Head, Inspection and Clean-
ing.
²Check camshaft bearing journals for scratches
and worn areas. If light scratches are present, they
may be removed with 400 grit sand paper. If deep
Fig. 10 Ingition Coil Pack
Fig. 11 Servicing Spark Plug Tubes
Fig. 12 Spark Plug Tube Seals
NS/GSENGINE 9 - 7
REMOVAL AND INSTALLATION (Continued)
HYDRAULIC LASH ADJUSTER NOISE
A tappet-like noise may be produced from several
items. Refer to Lash Adjuster Noise - Diagnosis in
Standard Service Procedures, outlined in this Group.
Lash adjusters are replaced with the rocker
arm as an assembly.
VALVE SEALS AND SPRINGS IN VEHICLE
REMOVAL
(1) Remove rocker arm shafts assemblies as previ-
ously outlined in this section.
(2) Rotate crankshaft until piston is at TDC on
compression.
(3) With air hose attached to adapter tool installed
in spark plug hole, apply 90-120 psi air pressure.
(4) Using Special Tool MD-998772A with adapter
6779 (Fig. 19) compress valve springs and remove
valve locks.
(5) Remove valve spring.
(6) Remove valve stem seal by using a valve stem
seal tool (Fig. 20).
INSTALLATION
(1) Install valve seal/valve spring seat assembly
as outlined in the Valve Installation procedure in this
section.
(2) Using Special Tool MD-998772A compress valve
springs only enough to install locks. Correct align-
ment of tool is necessary to avoid nicking valve stems
(air pressure required), piston at TDC.
(3) Install rocker arm shaft assemblies as previ-
ously outlined in this section.
(4) Install valve cover as previously outlined in
this section.
CYLINDER HEAD
REMOVAL
(1) Perform fuel system pressure release procedure
before attempting any repairs.Refer to Group 14,
Fuel System
(2) Disconnect negative battery cable. Drain cool-
ing system. Refer to Group 7, Cooling System.
(3) Disconnect all vacuum lines, electrical wiring
and fuel lines from throttle body.
(4) Remove throttle linkage.
(5) Remove accessory drive belts. Refer to Group 7,
Cooling System for procedure.
(6) Remove power brake vacuum hose from intake
manifold.
(7) Raise vehicle and remove exhaust pipe from
manifold.
(8) Remove power steering pump assembly and set
aside.
(9) Disconnect coil pack wiring connector and
remove coil pack and bracket from engine.
(10) Remove cylinder head cover.
(11) Remove cam sensor and fuel injectors wiring
connectors.
(12) Remove intake manifold. Removal procedure
outline in Group 11.
Fig. 19 Removing and Installing Valve Spring
Fig. 20 Valve Stem Oil Seal Tool
Fig. 21 Valve Spring Assembly
9 - 10 ENGINENS/GS
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
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)
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 3.5 bars to 5.0 bars at 4000 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 2 condi-
tions 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.
OIL LEVEL 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 cre-
ate 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 1 tappet will be
noisy. When oil level and leaks have been corrected,
operate the engine at fast idle. Run engine for a suf-
ficient 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 the
plunger partially sticking in the tappet body cylinder.
The tappet should be replaced. A heavy click iscaused by a tappet check valve not seating or by for-
eign particles becoming wedged between the plunger
and the tappet body. This will cause the plunger to
stick in the down position. This heavy click will be
accompanied by excessive clearance between the
valve stem and rocker arm as valve closes. In either
case, tappet assembly should be removed for inspec-
tion and cleaning.
(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. In general, if more than one tappet
seems to be noisy, its probably not the tappets.
SERVICE PROCEDURES
CHECKING OIL LEVEL
To assure proper engine lubrication, the engine oil
must be maintained at the correct level. Check the
oil level at regular intervals, such as every fuel stop.
The best time to check the oil level is about 5 min-
utes after a fully warmed-up engine is shut off, or
before starting the vehicle after it has sat overnight.
Checking the oil while the vehicle is on level
ground, will improve the accuracy of the oil level
readings (Fig. 4).
CHANGING ENGINE OIL AND FILTER
Change engine oil and filter at mileage and time
intervals described in the Maintenance Schedule.
Fig. 4 Checking Engine Oil
NS/GSENGINE 9 - 47
DIAGNOSIS AND TESTING (Continued)
ENGINE ASSEMBLY
REMOVAL
(1) Disconnect the battery.
(2) Remove the air cleaner assembly and inlet
hose.
(3) Remove both hoses at intercooler and engine.
(4) Disconnect EGR vacuum hose.
(5) Disconnect brake booster vacuum hose.
(6) Disconnect oil pressure switch connector (Fig.
19).
(7) Disconnect Wiring harness bracket at transaxle
shift tower.
(8) Disconnect transaxle wiring at speed sensor,
crank sensor, and backup light switch.
(9) Remove both transmission shift cables at trans-
mission.
(10) Remove negative battery cable at cylinder
block (Fig. 19).
(11) Remove oil separator.
(12) Remove connectors at coolant temperature
sensor and A/C compressor.
(13) Disconnect fuel injection pump wiring connec-
tors (Fig. 19).
(14) Disconnect glow plug connectors.
(15) Disconnect electrical connector at number 1
fuel injector.
(16) Raise vehicle on hoist.
(17) Remove right side splash shield (Fig. 20).
WARNING: THE COOLANT IN A RECENTLY OPER-
ATED ENGINE IS HOT AND PRESSURIZED. USE
CARE TO PREVENT SCALDING BY HOT COOLANT.CAREFULLY RELEASE THE PRESSURE BEFORE
REMOVING THE RADIATOR DRAIN COCK AND CAP.
(18) Drain the cooling system (refer to Group 7,
Cooling).
(19) Lower vehicle.
(20) Remove Coolant pressure bottle and discon-
nect low coolant level sensor.
(21) Disconnect both heater hoses.
(22) Remove the lower radiator hose.
(23) Remove the upper radiator hose.
(24) Remove fuel line at injector pump and cap.
(25) Remove power steering reservoir and reposi-
tion.
(26) Remove upper radiator crossmember.
(27) Disconnect cooling fan module connector.
Fig. 18 Shift Cables at Rear MountFig. 19 Component Locations
Fig. 20 Right Side Splash Shield
NS/GSENGINE 9 - 53
REMOVAL AND INSTALLATION (Continued)