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)
ENGINE DIAGNOSISÐMECHANICAL CONT.
CONDITION POSSIBLE CAUSES CORRECTION
LUBRICATING OIL LOSS
(CONT.)6. Turbocharger leaking oil into the
air intake.6. Inspect air duct for evidence of oil
transfer.
7. Piston rings not sealing (oil being
consumed by the engine).7. Perform blow-by check. Repair as
required.
COMPRESSION KNOCKS 1. Air in fuel system. 1. Bleed the fuel system (refer to
Group 14, Fuel System).
2. Poor quality fuel or water/gasoline
contaminated fuel.2. Verify by operating from a
temporary tank with good fuel. Clean
and flush the fuel supply tank.
Replace fuel/water separator.
3. Engine Overloaded. 3. Verify the engine load rating is not
being exceeded.
4. Improperly operating injectors. 4. Check and replace injectors.
5. Fuel injection system defective. 5a. Instrumented injection. 5b. Timing
solenoid of the fuel pump. 5c. Pre
and post heat time of the glow plugs.
Check the fault codes in the ECU.
EXCESSIVE ENGINE NOISES 1. Drive belt squeal, insufficient
tension or abnormally high loading.1. Inspect the drive belts. Make sure
water pump pulley, generator and
power steering all turn freely.
2. Intake air and exhaust leak. 2. Refer to excessive exhaust smoke.
(Engine Diagnosis and Testing)
3. Excessive valve lash. 3. Make sure the rocker arms are not
bent. Defective hydraulic lash
adjuster.
4. Turbocharger noise. 4. Check turbocharger impeller and
turbine wheel for housing contact.
5. Power function knock. 5. Check and replace rod and main
bearings.
6. Fuel injection system defective. 6a. Instrumented injection. 6b. Timing
solenoid of the fuel pump. 6c. Pre
and post heat time of the glow plugs.
Check the fault codes in the ECU.
NS/GSENGINE 9 - 45
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)
VALVE STAND DOWN
Valve stand down is to maintain the adequate com-
pression ratio.
(1) Invert cylinder head.
(2) Fit each valve to its respective valve guide.
(3) Using a straight edge and feeler gauge (Fig. 9),
check valve head stand down: Inlet valve head stand
down .80 to 1.2 mm (.031 to .047 in.) and exhaust
valve stand down .79 to 1.19 mm (.031 to .047 in).
(4) If valve head stand down is not in accordance
with above, discard original valves, check stand down
with new valves and recut valve seat inserts to
obtain correct stand down.
VALVE GUIDE HEIGHT
(1) Valve Guides height requirement.
(2) Measurement A (Fig. 10): 13.50 - 14.00 mm.
VALVE STEM-TO-GUIDE CLEARANCE
MEASUREMENT
(1) Measure and record internal diameter of valve
guides. Valve guide internal diameter is 8.0 to 8.015
mm (.3149 to .3155 in.).
(2) Measure valve stems and record diameters.
Intake valve stem diameter 7.94 to 7.96 mm (.3125 to
.3133 in). Exhaust valve stem diameter 7.92 to 7.94
mm (.3118 to .31215 in).(3) Subtract diameter of valve stem from internal
diameter of its respective valve guide to obtain valve
stem clearance in valve guide. Clearance of inlet
valve stem in valve guide is .040 to .075 mm (.0015
to .0029 in). Clearance of exhaust valve stem in valve
guide is .060 to .095 mm (.0023 to .0037 in).
(4) If valve stem clearance in valve guide exceeds
tolerances, new valve guides must be installed.
FITTING PISTON RING
(1) Wipe cylinder bore clean. Insert ring and push
down with piston to ensure it is square in bore. The
ring gap measurement must be made with the ring
positioning at least 12 mm (0.50 in.) from bottom of
cylinder bore (Fig. 11). Check gap with feeler gauge.
Top compression ring gap .25 to .50mm (.0098 to
.0196 in.). Second compression ring gap .25 to .35mm
(.0098 to .0137 in.). Oil control ring gap .25 to .58mm
(.0098 to .0228 in.).
(2) If ring gaps exceed dimension given, new rings
or cylinder liners must be fitted. Keep piston rings in
piston sets.
(3) Check piston ring to groove clearance (Fig. 12).
Top compression ring gap .08 to .130mm (.0031 to
.0051 in.). Second compression ring gap .070 to
.102mm (.0027 to .0040 in.). Oil control ring gap .040
to .072mm (.0015 to .0028 in.).
CRANKSHAFT END PLAY
(1) Attach dial indicator to engine block (Fig. 13).
(2) Move crankshaft toward front of engine and
zero indicator.
(3) Move crankshaft toward the rear of engine and
record measurement.
(4) Subtract specified crankshaft end float from
figure obtained. Crankshaft end float 0.08 to
0.21mm.
(5) Select thrust washer which will give correct
end float.
Fig. 9 Checking Valve Stand Down
Fig. 10 Valve Guide Height
Fig. 11 Ring Gap Measurement
9 - 50 ENGINENS/GS
SERVICE PROCEDURES (Continued)
70É using angle torque tool. Then rotate the bolts an
additional 70É following tightening sequence.
(10) Then, tighten the 14mm bolts with special
tool VM-1018 in the following manner:
(11) Side bolts (M1-M2): Tighten M1 bolts to 30
N´m, then rotate them 85É (65). Tighten M2 bolts to
30 N´m, then rotate them 85É (65).
(12)2nd Phase:After 20 minutes of engine oper-
ation at operating temperature, allow engine to cool
down completely. Then retorque the head bolts as fol-
lows:
(13) Central bolts A-L: Starting from bolt A,
slacken and retorque it immediately to 30 N´m + 65É.
Rotate the bolt an additional 65É. Then proceed in
the same way, bolt by bolt, following alphabetical
order, as indicated.
(14) Side bolts M1-M2:Without slackening,
torque bolts M1 then bolts M2 to 90 N´m (66 ft. lbs.).
(15) Tighten intake nuts to 30 N´m (22 ft. lbs.) and
exhaust manifolds nuts to 30 N´m (22 ft. lbs.) speci-
fied torque after completing Phase 2.
(16) If the engine cylinder head is to be replaced
and the original valves used, measure the valve stem
diameter. Only standard size valves can be used with
a service replacement engine cylinder head unless
the replacement head valve stem guide bores are
reamed to accommodate oversize valve stems.
Remove all carbon buildup and reface the valves.
(17) Tighten oil feed lines for rocker arm assem-
blies and oil pressure switch to 13 N´m (112 in. lbs.).
(18) Install push rods and rocker arm assemblies,
tighten nut to 29.4 N´m (264 in. lbs.).(19) Install fuel injectors use tool VM-1012 (refer
to Group 14, Fuel System).
(20) Install valve cover, tighten nuts to 14.7 N´m
(132 in. lbs.).
(21) Connect crankcase breather hose.
(22) Connect the injector sensor wire connector,
and the glow plug connectors.
(23) Install oil feed line, tighten banjo bolts to 12.7
N´m (108 in. lbs), and oil drain line to turbo.
(24) Install water manifold tighten bolts to 12 N´m
(106 in. lbs.).
(25) Install exhaust pipe to turbo elbow, tighten
bolts to 28 N´m (250 in. lbs.).
(26) Install the support strut from block to turbo-
charger exhaust elbow.
(27) Install EGR tube to EGR valve, tighten bolts
to 26 N´m (19 ft. lbs.).
(28) Install intercooler hoses at intake manifold.
(29) Install coolant pressure bottle and hoses.
(30) Install wiper module. Refer to Group 8K,
Windshield Wiper Unit Installation for procedure.
(31) Install intercooler hose at turbocharger tube.
(32) Install fuel injector lines from the pump to
injectors, tighten nuts to 17.6 N´m (156. lbs.).
(33) Connect the upper radiator hose.
(34) Connect negative cable to battery.
(35) Fill the cooling system. Check for leaks.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN DIRECT
LINE WITH THE FAN. DO NOT PUT HANDS NEAR
THE PULLEYS, BELTS OR FAN. DO NOT WEAR
LOOSE CLOTHING.
Fig. 33 Engine Cylinder Head Bolt Tightening Sequence
NS/GSENGINE 9 - 59
REMOVAL AND INSTALLATION (Continued)
THRUST PLATE INSPECTION
Check the thickness (Fig. 40) of the plate at points
a-b-c-d. If the measurement is not between 3.950 -
4.050 it must be changed.
INSTALLATION
(1) Coat the camshaft journals with clean engine
oil and carefully install the camshaft complete with
thrust plate and gear. Tighten the retaining bolts to
24 N´m. Be sure to align the timing marks as shown.(2) Install hydraulic tappets and retaining yokes.
(3) Install cylinder heads.
(4) Push rods, and rocker arm assemblies. In there
original location.
(5) Install valve cover.
(6) Install Timing case cover.
(7) Install Vibration damper.
(8) Reinstall Engine.
CAMSHAFT BEARINGS
This procedure requires that the engine is removed
from the vehicle.
REMOVAL
(1) With engine completely disassembled, drive out
rear cam bearing core hole plug.
(2) Install proper size adapters and horseshoe
washers (part of Camshaft Bearing Remover/Installer
Tool) at back of each bearing shell. Drive out bearing
shells.
INSTALLATION
(1) Install new camshaft bearings with Camshaft
Bearing Remover/Installer Tool by sliding the new
camshaft bearing shell over proper adapter.
(2) Position rear bearing in the tool. Install horse-
shoe lock and by reversing removal procedure, care-
fully drive bearing shell into place.
(3) Install remaining bearings in the same man-
ner. Bearings must be carefully aligned to bring oil
holes into full register with oil passages from the
main bearing. If the camshaft bearing shell oil holes
are not in exact alignment, remove and install them
correctly. Install a new core hole plug at the rear of
camshaft.Be sure this plug does not leak.
CRANKSHAFT MAIN BEARINGS
REMOVAL
(1) Disconnect battery cable.
(2) Remove engine from vehicle, refer to engine
removal in this section.
(3) Install engine to engine stand.
(4) Remove accessary drive system.
(5) Remove cylinder head cover, refer to cylinder
head cover removal in this section.
(6) Remove rocker arm and push rods, refer to
rocker arm and push rod section in this section.
(7) Remove intake, exhaust manifold and turbo-
charger, refer to Group 11, Exhaust System and
Intake Manifold.
(8) Remove water manifold.
(9) Remove oil feed lines to rocker arms.
(10) Remove cylinder heads.
(11) Remove oil pan and oil pick-up.
(12) Remove piston and connecting rods from
crankshaft journals.
Fig. 39 Camshaft Removal
Fig. 40 Camshaft Thrust Plate
NS/GSENGINE 9 - 63
REMOVAL AND INSTALLATION (Continued)