ENGINE BLOCK
CLEANING
Thoroughly clean the oil pan and engine block gasket surfaces.
Use compressed air to clean out:
The galley at the oil filter adaptor hole.
The front and rear oil galley holes.
The feed holes for the crankshaft main bearings.
Once the block has been completely cleaned, apply Loctite PST pipe sealantwith Teflon 592 to the threads of the
front and rear oil galley plugs. Tighten the 1/4 inch NPT plugs to 20 Nꞏm (177in. lbs.) torque. Tighten the 3/8 inch
NPT plugs to 27 Nꞏm (240 in. lbs.) torque.
INSPECTION
1. It is mandatory to use a dial bore gauge to mea-
sure each cylinder bore diameter. To correctly
select the proper size piston, a cylinder bore
gauge, capable of reading in 0.003 mm (.0001 in.)
INCREMENTS is required. If a bore gauge is not
available, do not use an inside micrometer.
2. Measure the inside diameter of the cylinder bore at
three levels below top of bore. Start perpendicular
(across or at 90 degrees) to the axis of the crank-
shaft and then take two additional reading.
3. Measure the cylinder bore diameter crosswise to
the cylinder block near the top of the bore. Repeat
the measurement near the middle of the bore, then
repeat the measurement near the bottom of the
bore.
4. Determine taper by subtracting the smaller diame-
ter from the larger diameter.
5. Rotate measuring device 90° and repeat steps
above.
6. Determine out-of-roundness by comparing the dif-
ference between each measurement.
7. If cylinder bore taper does not exceed 0.025 mm (0.001 inch) and out-of-roundness does not exceed 0.015 mm
(0.0006 inch), the cylinder bore can be honed. If the cylinder bore taper orout- of-round condition exceeds these
maximum limits, the cylinder block must be replaced. A slight amount of taper always exists in the cylinder bore
after the engine has been in use for a period of time.
TAPPETS - HYDRAULIC ROLLER
DIAGNOSIS AND TESTING - HYDRAULIC TAPPETS
Before disassembling any part of the engine to correct tappet noise, checkthe 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
(30-70 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 conditions could be responsible for noisy tappets.
OIL LEVEL
HIGH
If oil level is above the FULL mark, it is possible for the connecting rods todip 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 bedrawn 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, crank over engine 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 noisytappets. If such is the case,
noise may be dampened by applying side thrust on the valve spring. If noise is not appreciably 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 noiseis usually caused by excessive 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 is caused by a tappet check valve not seating, or by foreign 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
accompanied by excessive clearance between the valve stem and rocker arm as valve closes. In either case,
tappet assembly should be removed for inspection 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 making the noise. If more than one tappet seems to be noisy, it’s probably not
the tappets.
REMOVAL
1. Disconnect the negative cable from the battery.
2. Remove the air cleaner (Refer to 9 - ENGINE/AIR INTAKE SYSTEM - REMOVAL).
3. Remove intake manifold (Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD-REMOVAL).
4. Remove cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDERHEAD COVER(S) -
REMOVAL).
5. Remove rocker arm assembly and push rods (Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER ARM /
ADJUSTER ASSY - REMOVAL). Identify push rods to ensure installation in original location.
6. Remove the cylinder head (Refer to 9 - ENGINE/CYLINDER HEAD - REMOVAL).
SOLENOID-MDS
DESCRIPTION
The Multi Displacement System selectively deactivates cylinders 1,4,6,and 7, to improve fuel economy. It has two
modes of operation :
8 cylinders for acceleraton and heavy loads.
4 cylinders for cruising and city traffic.
The main components of the Multi Displacement System are :
Unique MDS camshaft.
Deactivating roller tappets.
4 control valves/solenoids.
control valve/solenoid wiring harness.
oil temp sensor.
OPERATION
Cylinder Deactivation
Trap an exhaust charge from a normal combustion event
Normal combustion event
Don’t open the exhaust valve
Don’t open the intake valve
Piston is an air spring
Cylinders deactivated in firing sequence
Cylinder Reactivation
Open the exhaust valve
Empty the cylinder
Open the intake valve
Normal combustion event
Cylinders reactivated in firing sequence
DIAGNOSIS AND TESTING
The Multi Displacement System has the following detectible issues:
Solenoid circuit
Fail to deactivate a cylinder(s)
Fail to reactivate a cylinder(s)
Low oil pressure
CONDITION POSSIBLE CAUSES CORRECTION
MDS does not activate 1. Low oil pressure 1. Check for proper oil pressure
2. Bad oil temp sensor 2. Replace oil temp sensor
3. Malfunctioning MDS Solenoid 3. Replace Solenoid
4. Malfunctioning MDS Tappet 4. Replace Tappet
MDS Does Not Deactivate 1. Low oil pressure 1. Check for proper oil pressure
2. Bad oil temp sensor 2. Replace oil temp sensor
3. Malfunctioning MDS Solenoid 3. Replace Solenoid
4. Malfunctioning MDS Tappet 4. Replace Tappet
MANIFOLD - INTAKE
DESCRIPTION
The intake manifold is made of a composite material and features long runners which maximizes low end torque.
The intake manifold uses single plane sealing which consist of eight individual press in place port gaskets to prevent
leaks.
DIAGNOSIS AND TESTING - INTAKE MANIFOLD LEAKAGE
An intake manifold air leak is characterized by lower than normal manifoldvacuum. Also, one or more cylinders may
not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING. DO NOT STAND IN ADIRECT 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 RPM is observed the area of the suspected leak has been found.
4. Repair as required.
REMOVAL
1. Disconnect negative cable from battery.
2. Remove resonator assembly and air inlet hose.
3. Disconnect electrical connectors for the following components:
Manifold Absolute Pressure (MAP) Sensor
Intake Air Temperature (IAT) Sensor
Throttle Position (TPS) Sensor
Coolant Temperature (CTS) Sensor
4. Disconnect brake booster hose and positive crankcase ventilation (PCV)hose.
5. Remove generator and set aside.
NOTE: It is not necessary to remove lines or remove freon from A/C compressor.
6. Remove air conditioning compressor and set aside..
7. Bleed fuel system (Refer to 14 - FUEL SYSTEM/FUEL DELIVERY - STANDARD PROCEDURE).
8. Remove intake manifold retaining fasteners in a crisscross pattern starting from the outside bolts and ending at
themiddlebolts.
9. Remove intake manifold and IAFM as an assembly.
CLEANING
NOTE: There is NO approved repair procedure for the intake manifold. If severe damage is found during
inspection, the intake manifold must be replaced.
Before installing the intake manifoldthoroughly clean the mating surfaces. Use a suitable cleaning solvent, then air
dry.
CONDITION POSSIBLE CAUSES CORRECTION
11. Directed piston cooling nozzles
under piston, bad fit into main
carrier.11. Check directed piston cooling nozzles
position.
12. Loose oil rifle plug with saddle-jet
style nozzles12.Tighten oil rifle plug.
13. Loose directed piston cooling
nozzle.13. Tighten directed piston cooling nozzle.
14. Both J-jet and saddle jet style
cooling nozzle installed.14. Install correct style jet.
LUBRICATING OIL
PRESSURE TOO HIGH1. Pressure switch/gauge not
operating properly.1. Verify pressure switch is functioning
correctly. If not, replace switch/gauge.
ENGINE BREATHER
RESTRICTED2. Engine running too cold. 2. Refer to Coolant Temperature Below
Normal (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
3. Oil viscosity too thick. 3. Make sure the correct oil is being used.
(Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
4. Oil pressure relief valve stuck
closed or binding4. Check and replace valve.
LUBRICATING OIL LOSS 1. External 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.3. (a) Make sure the correct oil is being
used (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
(b) Look for reduced viscosity from dilution
with fuel.
(c) Review/reduce 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. Perform the required repairs.
6. Turbocharger leaking oil to the air
intake.6. Inspect the air ducts for evidence of oil
transfer. Repair as required.
COMPRESSION KNOCKS 1. Air in the fuel system. 1. Identify location of air leak and repair. Do
not bleed high pressure 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 tank. Replace fuel/water separator filter.
3. Engine overloaded. 3. Verify the engine load rating is not being
exceeded.
4. Improperly operating injectors. 4. Check and replace misfiring/inoperative
injectors.
EXCESSIVE VIBRATION 1. Loose or broken engine mounts. 1. Replace engine mounts.
2. Damaged fan or improperly
operating accessories.2. Check and replace the vibrating
components.
CONDITION POSSIBLE CAUSES CORRECTION
3. Improperly operating vibration
damper3. Inspect/replace vibration damper.
4. Improperly operating electronically
controlled viscous fan drive.4. Inspect/replace fan drive.
5. Worn or damaged generator
bearing.5. Check/replace generator.
6. Flywheel housing misaligned. 6. Check/correct flywheel alignment.
7. Loose or broken power
component.7. Inspect the crankshaft and rods for
damage that causes an unbalance
condition. Repair/replace as required.
8. Worn or unbalanced driveline
components.8. Check/repair driveline components.
EXCESSIVE ENGINE
NOISES1. Drive belt squeal, insufficient
tension or abnormally high loading.1. Check the automatic tensioner and
inspect the drive belt. Make sure water
pump, tensioner pulley, fan hub, generator
and power steering pump turn freely.
2. Intake air or exhaust leaks. 2. Refer to Excessive Exhaust Smoke
(Refer to 9 - ENGINE - DIAGNOSIS AND
TESTING).
3. Excessive valve lash. 3. Adjust valves. Make sure the push rods
are not bent and rocker arms, adjusting
screws, crossheads, are not severely worn.
Replace bent or severely worn components.
4. Turbocharger noise. 4. Check turbocharger impeller and turbine
wheel for housing contact. Repair/replace
as required.
5. Gear train noise. 5. Visually inspect and measure gear
backlash. Replace gears as required.
6. Power function knock. 6. Check/replace rod and main bearings.
DIAGNOSIS AND TESTING -SMOKE DIAGNOSIS CHARTS
The following charts include possible causes and corrections forexcess or abnormalexhaust smoke. Small
amounts of exhaust smoke (at certain times) are to be considered normal fora diesel powered engine.
EXCESSIVE BLACK SMOKE
POSSIBLE CAUSE CORRECTION
Air filter dirty or plugged. Check Filter Minder
at air filter (Refer to 9 - ENGINE/
AIR INTAKE SYSTEM/AIR CLEANER ELEMENT -
REMOVAL).
Air intake system restricted. Check entire air intake system including all hoses and
tubes for restrictions, collapsed parts or damage.
Repair/replace as necessary.
Air Leak in Intake System. Check entire air intake system (Refer to 11 - EXHAUST
SYSTEM/TURBOCHARGER SYSTEM/CHARGE AIR
COOLER AND PLUMBING - DIAGNOSIS AND
TESTING) including all hoses and tubes for cracks,
loose clamps and/or holes in rubber ducts. Also check
intake manifold for loose mounting hardware.
Diagnostic Trouble Codes (DTC’s) active or multiple,
intermittent DTC’s.Refer to Powertrain Diagnostic Procedures Information.
EXCESSIVE BLACK SMOKE
POSSIBLE CAUSE CORRECTION
Engine Control Module (ECM) not calibrated or ECM
has incorrect calibration.Refer to Powertrain Diagnostic Procedures Information.
Exhaust system restriction is above specifications. Check exhaust pipesfor damage/restrictions. Repair as
necessary.
Fuel grade is not correct or fuel quality is poor. Temporarily change fuel brands and note condition.
Change brand if necessary.
Fuel injection pump malfunctioning. A DTC may have been set. If so, refer toPowertrain
Diagnostic Procedures Information.
Fuel injector malfunctioning. A DTC may have been set. Perform “Cylinder
Performance Test
orCylinder Cutout Testusing DRB
scan tool to isolate individual cylinders. Also refer to
Powertrain Diagnostic Procedures Information and, to
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/FUEL
INJECTOR - DIAGNOSIS AND TESTING).
Fuel return system restricted. Check fuel return lines for restriction (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - DIAGNOSIS AND
TESTING).
Intake manifold restricted. Remove restriction.
Manifold Air Pressure (Boost) Sensor or sensor circuit
malfunctioning.A DTC should have been set. Refer to Powertrain
Diagnostic Procedures Information.
Raw fuel in intake manifold. Fuel injectors leaking on engine shutdown. DoFuel
Injector Test (Refer to 14 - FUEL SYSTEM/FUEL
INJECTION/FUEL INJECTOR - DIAGNOSIS AND
TESTING).
Turbocharger air intake restriction. Remove restriction.
Turbocharger damaged. (Refer to 11 - EXHAUST SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER - INSPECTION).
Turbocharger has excess build up on compressor
wheel and/or diffuser vanes.(Refer to 11 - EXHAUST SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER - CLEANING).
Turbocharger wheel clearance out of specification. (Refer to 11 - EXHAUSTSYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER - INSPECTION).
EXCESSIVE WHITE SMOKE
POSSIBLE CAUSE CORRECTION
Air in fuel supply: Possible leak in fuel supply side.(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/FUEL
TRANSFER PUMP - DIAGNOSIS AND TESTING).
Coolant leaking into combustion chamber. Do pressure test of cooling system (Refer to 7 -
COOLING - DIAGNOSIS AND TESTING).
Diagnostic Trouble Codes (DTC’s) active or multiple,
intermittent DTC’s.Refer to Powertrain Diagnostic Procedures Information.
In very cold ambient temperatures, engine block heater
is malfunctioning (if equipped).(Refer to 7 - COOLING/ENGINE/ENGINE BLOCK
HEATER - REMOVAL).
Engine coolant temperature sensor malfunctioning. A DTC should have beenset. Refer to Powertrain
Diagnostic Procedures Information. Also check
thermostat operation (Refer to 7 - COOLING/ENGINE/
ENGINE COOLANT THERMOSTAT - DIAGNOSIS AND
TESTING).
Engine Control Module (ECM) not calibrated or has
incorrect calibration.A DTC should have been set. Refer to Powertrain
Diagnostic Procedures Information.
EXCESSIVE WHITE SMOKE
POSSIBLE CAUSE CORRECTION
Fuel filter plugged. Refer to Powertrain Diagnostic Manual for fuel system
testing.
Fuel grade not correct or fuel quality is poor. Temporarily change fuel brands and note condition.
Change brand if necessary.
Fuel heater element or fuel heater temperature sensor
malfunctioning. This will cause wax type build-up in fuel
filter.Refer to Fuel Heater Testing (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY/FUEL HEATER -
DIAGNOSIS AND TESTING).
Fuel injector malfunctioning. A DTC should have been set. Perform “Cylinder
Performance Test
orCylinder cutout Testusing DRB
scan tool to isolate individual cylinders. Also refer to
Powertrain Diagnostic Procedures Information and,
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/FUEL
INJECTOR - DIAGNOSIS AND TESTING).
Fuel injector hold-downs loose. Torque to specifications.
Fuel injector protrusion not correct. Check washer (shim) at bottom of fuel injector for
correct thickness. (Referto 14 - FUEL SYSTEM/FUEL
INJECTION/FUEL INJECTOR - INSTALLATION)
Fuel injection pump malfunctioning. A DTC should have been set. Refer to Powertrain
Diagnostic Procedures Information.
Fuel supply side restriction. Refer to Powertrain Diagnostic Manual for fuel system
testing.
Fuel transfer (lift) pump malfunctioning. A DTC may have been set. Refer toPowertrain
Diagnostic Procedures Information.
Intake/Exhaust valve adjustments not correct (too tight). (Refer to 9 - ENGINE/CYLINDER HEAD/INTAKE/
EXHAUST VALVES & SEATS - STANDARD
PROCEDURE).
Intake manifold air temperature sensor malfunctioning. A DTC should havebeen set. Refer to Powertrain
Diagnostic Procedures Information.
Intake manifold heater circuit not functioning correctly in
cold weather.A DTC should have been set. Refer to Powertrain
Diagnostic Procedures Information. Also check heater
elements for correct operation.
Intake manifold heater elements not functioning
correctly in cold weather.A DTC should have been set if heater elements are
malfunctioning. Refer to Powertrain Diagnostic
Procedures Information.
Internal engine damage (scuffed cylinder). Analyze engine oil and inspect oil filter to locate area of
probable damage.
Restriction in fuel supply side of fuel system. Refer to Powertrain Diagnostic Manual for fuel system
testing.
EXCESSIVE BLUE SMOKE
POSSIBLE CAUSE CORRECTION
Dirty air cleaner or restricted turbocharger intake duct. Check Filter Minder
at air filter housing. (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
ELEMENT - REMOVAL).
Air leak in boost system between turbocharger
compressor outlet and intake manifold.Service air charge system..
Obstruction in exhaust manifold. Remove exhaust manifold and inspect forblockage
(Refer to 9 - ENGINE/MANIFOLDS/EXHAUST
MANIFOLD - REMOVAL).