EXCESSIVE BLUE SMOKE
POSSIBLE CAUSE CORRECTION
Restricted turbocharger drain tube. Remove turbocharger drain tube and remove
obstruction.
Crankcase ventilation system plugged. Inspect crankcase ventilation system for function
Valve seals are worn, brittle, or improperly installed. Replace valve stemoilseals(Referto9-ENGINE/
CYLINDER HEAD/INTAKE/EXHAUST VALVES &
SEATS - REMOVAL).
Valve stems and/or guides are worn. Remove valves and inspect valves and guides. (Refer
to 9 - ENGINE/CYLINDER HEAD/INTAKE/EXHAUST
VALVES & SEATS - STANDARD PROCEDURE).
Broken or Improperly installed piston rings. Tear down engine and inspectpiston rings.
Excessive piston ring end gap. Remove pistons and measure piston ring end gap
(Refer to 9 - ENGINE/ENGINE BLOCK/PISTON RINGS
- STANDARD PROCEDURE).
Excessive cylinder bore wear and taper. Remove pistons and measure cylinder bore wear and
taper (Refer to 9 - ENGINE/ENGINE BLOCK -
STANDARD PROCEDURE).
Cylinder damage. Remove pistons and inspect cylinder bore for cracks or
porosity. Repair with cylinder liner if necessary. (Refer
to 9 - ENGINE/ENGINE BLOCK - STANDARD
PROCEDURE).
Piston damage. Remove pistons and inspect for cracks, holes. Measure
piston for out-of-round and taper (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON & CONNECTING
ROD - INSPECTION).
Turbocharger failure. (Refer to 11 - EXHAUST SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER - INSPECTION).
DIAGNOSIS AND TESTING - CYLINDER COMPRESSION/LEAKAGE TESTS
CYLINDER COMPRESSION PRESSURE
The results of a cylinder compressionpressure test can be utilized to diagnose several engine malfunctions.
Ensure batteries are completely charged and the engine starter motor is ingood operating condition. Otherwise, the
indicated compression pressures may not be valid for diagnostic purposes.
1. Disconnect the fuel inlet line to the fuel filter housing. Plug the fuel line from the fuel tank.
NOTE: Failure to plug fuel line will result in fuel leak.
2. Remove fuel transfer pump relay from PDC.
3. Start the engine and idle until the engine stalls (runs out of fuel).
4. Remove the cylinder head cover. (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) -
REMOVAL)
5. Remove the cylinder head cover carrier gasket. (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL)
6. Remove the high pressure fuel line between the cylinder head and fuel rail for the cylinder to be tested. Use
tool# 9011 to cap this fuel rail on the cylinder being tested.
7. Remove the fuel connector tube nut and fuel connector tube.
8. Remove the exhaust rocker lever.
9. Use Tool 9010 to remove the injector and copper sealing washer.
10. Install the exhaust rocker lever and torque to 36 Nꞏm (27 ft. lbs.).
11. Cover the remaining rocker levers with clean shop towels to prevent anyoil splatter under the hood.
3. Place a shop towel around the fuel injectors to catch any fluid that may possibly be under pressure in the cyl-
inder head. Remove the fuel injectors (Refer to 14 - FUEL SYSTEM/FUEL INJECTION/FUEL INJECTOR -
REMOVAL).
4. With all injectors removed, rotatethe crankshaft using the crankshaftbarring tool (PN 7471–B).
5. Identify the fluid in the cylinders (coolant, fuel, oil, etc.).
6. Be sure all fluid has been removed from the cylinders.
7. Repair engine or components as necessary to prevent this problem from occurring again.
8. Squirt a small amount of engine oil into the cylinders to lubricate the walls. This will prevent damage on restart.
9. Install fuel injectors (Refer to 14 - FUEL SYSTEM/FUEL INJECTION/FUEL INJECTOR - INSTALLATION).
10. Drain engine oil. Remove and discard the oil filter (Refer to 9 - ENGINE/LUBRICATION/OIL FILTER -
REMOVAL).
11. Installthedrainplug.Tightentheplugto50Nꞏm(37ft.lbs.)torque.
12. Install a new oil filter (Refer to 9 - ENGINE/LUBRICATION/OIL FILTER - INSTALLATION).
13. Fill engine crankcase with the specified amount and grade of oil (Referto LUBRICATION & MAINTENANCE/
FLUID TYPES - SPECIFICATIONS).
14. Connect the negative cable(s) to the battery.
15. Start the engine and check for any leaks.
REMOVAL - ENGINE
1. Disconnect both battery negative cables.
2. Disconnect engine grid heater harness at grid
heater relays.
3. Disconnect electrical connections from rear of alter-
nator.
4. Recover A/C refrigerant. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - STANDARD
PROCEDURE).
5. Raise vehicle on a hoist.
6. Drain engine coolant (Refer to 7 - COOLING -
STANDARD PROCEDURE).
7. Remove engine oil drain plug and drain engine oil.
8. Reinstall drain plug. Tighten to 50 Nꞏm (37 ft. lbs.)
torque.
9. Lower the vehicle.
10. Remove fan (3) and fan drive (2). Refer to (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
AIR CLEANER ELEMENT
REMOVAL
Testing Air Cleaner Element using Filter Minder™
Do not attempt to unnecessarily remove top of air
cleaner housing for air cleaner element inspection
on diesel engines.
The air cleaner (filter) housing (5) is equipped with an
air Filter Minder™ gauge (3). This air flow restriction
gauge will determine when air cleaner element is
restricted and should be replaced.
The Filter Minder™ (5) consists of a diaphragm and
calibrated spring sealed inside of a plastic housing. A
yellow colored disc (2) attached to diaphragm moves
along a graduated scale on side of Filter Minder. After
the engine has been shut off, a ratcheting device
located within Filter Minder will hold yellow disc at
highest restriction that air cleaner element has experi-
enced. A drop in air pressure due to an air cleaner
element restriction moves diaphragm and yellow disc
will indicate size of air drop.
CAUTION: Certain engine degreasers or cleaners
may discolor or damage plastic housing of Filter
Minder. Cover and tape Filter Minder if any engine
degreasers or cleaners are to be used.
To test, turn engine off. If yellow disc (2) has reached
red colored zone (3) on graduated scale, air cleaner
element should be replaced. Refer to Removal /
Installation.
Resetting Filter Minder:After air cleaner (filter) ele-
ment has been replaced, press rubber button on top of Filter Minder. This will allow yellow colored disc to reset.
After button has been pressed, yellow disc should spring back to UP position.
If Filter Minder gauge has reached red colored zone, and after an examination of air cleaner (filter) element, ele-
ment appears to be clean, high reading may be due to a temporary condition such as snow build-up at air intake.
Temporary high restrictions may also occur if air cleaner (filter) element has gotten wet such as during a heavy rain
or snow. If this occurs, allow element to dry out during normal engine operation. Reset rubber button on top of Filter
Minder and retest after element has dried.
CAMSHAFT & BEARINGS (IN BLOCK)
REMOVAL
CAMSHAFT BEARINGS
NOTE: Measure the diameter of each bore. If the camshaft bore for the cam bushing is worn beyond the
limit, install a new service bushing. Inspect the rest of the camshaft bores for damage or excessive wear.If
the bores without a bushing are worn beyond the limit, the engine must be removed for machining and
installation of service bushings. If badly worn, replace the cylinder block.
1. Remove the camshaft (Refer to 9 - ENGINE/ENGINE BLOCK/CAMSHAFT & BEARINGS (IN BLOCK) -
REMOVAL).
2. Remove the bushing from the No.1 bore.
3. Mark the cylinder block so you can align the oil hole in the cylinder blockwith the oil hole in the bushing.
CAMSHAFT
1. Disconnect both battery negative cables.
2. Recover A/C refrigerant (if A/C equipped) (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE).
3. Raise vehicle on hoist.
4. Drain engine coolant into container suitable for re-use (Refer to 7 - COOLING - STANDARD PROCEDURE).
5. Lower vehicle.
6. Remove radiator upper hose.
7. Remove viscous fan/drive/shroud assembly (Refer to 7 - COOLING/ENGINE/RADIATOR FAN - REMOVAL).
8. Disconnect the coolant recovery bottle hose from the radiator filler neck.
9. Disconnect lower radiator hose from radiator outlet.
10.Automatic Transmission models:Disconnect transmission oil cooler lines from front of radiator using Special
Tool 6931 (unless equipped with finger-release disconnect).
11. Remove radiator mounting screws and lift radiator out of engine compartment.
12. Remove upper radiator support panel.
13. If A/C equipped, disconnect A/C condenser refrigerant lines.
14. Disconnect charge air cooler piping from the cooler inlet and outlet.
15. Remove the two charge air cooler mounting bolts.
16. Remove charge air cooler (and A/C condenser if equipped) from vehicle.
17. Remove accessory drive belt (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).
18. Remove accessory drive belt tensioner.
19. Remove the fan support/hub assembly.
20. Remove crankshaft damper and speed indicator ring (Refer to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL).
21. Remove the gear cover-to-housing bolts and gently pry the cover away from the housing, taking care not to mar
the sealing surfaces. Remove dust seal with cover.
22. Using Special Tool 7471–B Crankshaft Barring Tool, rotate the crankshaft to align the timing marks on the
crankshaft and the camshaft gears.
23. Remove the cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) -
REMOVAL).
12. Install gear housing cover (Refer to 9 - ENGINE/VALVE TIMING/GEAR HOUSING COVER - INSTALLATION).
Install front crankshaft dust seal.
13. Install the crankshaft damper with the speed indicator ring (Refer to 9- ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - INSTALLATION).
14. Install the fan support/hub assembly Refer to (Refer to 7 - COOLING/ENGINE/RADIATOR FAN - INSTALLA-
TION).
15. Install the power steering pump.
16. Install accessory drive belt tensioner. Torque bolt to 43 Nꞏm (32 ft. lbs.).
17. Install the accessory drive belt (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - INSTALLATION).
18. Install the charge air cooler (with a/c condenser and auxiliary transmission oil cooler, if equipped) and tighten
the mounting bolts to 2 Nꞏm (17 in. lbs.) torque.
19. Connect charge air cooler inlet and outlet pipes. Tighten clamps to 11 Nꞏm (95 in. lbs.) torque.
20. Install the radiator upper support panel.
21. Close radiator petcock and lower the radiator into the engine compartment. Tighten the mounting bolts to 11
Nꞏm (95 in. lbs.) torque.
22. Raise vehicle on hoist.
23. Connect radiator lower hose and install clamp.
24. Connect transmission auxiliary oil cooler lines (if equipped).
25. Lower vehicle.
26. Install the fandrive/shroud assembly. (Refer to 7 - COOLING/ENGINE/RADIATOR FAN - INSTALLATION)
27. Install the coolant recovery and windshield washer fluid reservoirs to the fan shroud.
28. Connect the coolant recovery hose to the radiator filler neck.
29. Add engine coolant (Refer to 7 - COOLING - STANDARD PROCEDURE).
30. Charge A/C system with refrigerant (if A/C equipped) (Refer to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - STANDARD PROCEDURE).
31. Connect the battery negative cables.
32. Start engine and check for engine oil and coolant leaks.
ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSES CORRECTION
ENGINE WILL NOT
CRANK1. Weak or discharged battery. 1. Charge or replace battery as necessary.
(Refer to 8 - ELECTRICAL/BATTERY
SYSTEM - DIAGNOSIS AND TESTING).
Check charging system. Refer to the
appropriate Diagnostic Information for
charging system diagnosis.
2. Corroded or loose battery
connections.2. Clean/tighten battery/starter connections.
3. Faulty starter or related circuits. 3. Check starting system. (Refer to8-
ELECTRICAL/STARTING - DIAGNOSIS
AND TESTING).
4. Seized accessory drive
component.4. Remove accessory drive belt and
attempt to start engine. If engine cranks,
repair/replace seized component.
5. Engine internal mechanical failure
or hydrostatic lock.5. (Refer to 9 - ENGINE - STANDARD
PROCEDURE - HYDROSTATIC LOCKED
ENGINE).
ENGINE CRANKS BUT
WILL NOT START1. No spark. 1. Check for spark. Refer to the appropriate
Diagnostic Information for ignition system
diagnosis.
2. No fuel. 2. Perform fuel pressure test. Refer to the
appropriate Diagnostic Information for fuel
system diagnosis.
3. Low or no engine compression. 3. Perform cylinder compression test.
(Refer to 9 - ENGINE - DIAGNOSIS AND
TESTING - CYLINDER COMPRESSION
PRESSURE TEST).
ENGINE LOSS OF
POWER1. Worn or incorrect gapped spark
plugs.1. Replace spark plugs or set gap.
2. Dirt or water in fuel system. 2. Clean system and replace fuel filter.
3. Faulty fuel pump. 3. Replace fuel pump.
4. Incorrect valve timing. 4. Correct valve timing.
5. Blown cylinder head gasket(s). 5. Replace cylinder head gasket(s).
6. Low compression. 6. Test cylinder compression. (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING -
CYLINDER COMPRESSION PRESSURE
TEST)
7. Burned, warped, or pitted valves. 7. Install new or reface valves as
necessary.
8. Plugged or restricted exhaust. 8. Replace parts as necessary.
9. Faulty ignition cables. 9. Replace ignition cables as necessary.
10. Faulty coil(s). 10. Test and replace as necessary.
CONDITION POSSIBLE CAUSES CORRECTION
ENGINE STALLS OR
ROUGH IDLE1. Carbon buildup on throttle plate. 1. Remove throttle body and de-carbon.
2. Engine idle speed too low. 2. Check Idle Air Control circuit. Refer to
the appropriate Diagnostic Information for
IAC motor testing.
3. Worn or incorrectly gapped spark
plugs.3. Replace spark plugs or set gap.
4. Faulty or crossed ignition cables. 4. Check for correct firing order or replace
ignition cables as necessary.
5. Faulty coil(s). 5. Test and replace as necessary.
6. Intake manifold vacuum leak. 6. Inspect intake manifold gasket and
vacuum hoses. Replace as necessary.
ENGINE MISSES ON
ACCELERATION1. Worn or incorrectly gapped spark
plugs.1. Replace spark plugs or set gap.
2. Faulty ignition cables. 2. Replace ignition cables as necessary.
3. Dirt or water in fuel system. 3. Clean system and replace fuel filter.
4. Burned, warped, or pitted valves. 4. Install new or reface valves as
necessary.
5. Faulty coil(s). 5. Test and replace as necessary.
ENGINE DIAGNOSIS - MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES 1. High or low oil level incrankcase. 1. Check for correct oil level. Adjust oil level
by draining or adding as needed.
2. Thin or diluted oil. 2. Change oil and filter.
3. Low oil pressure. 3. Check engine oil level. If OK, perform oil
pressure test. (Refer to 9 - ENGINE/
LUBRICATION - DIAGNOSIS AND
TESTING).
4. Dirt in tappets/lash adjusters. 4. Clean/replace hydraulic tappets/lash
adjusters.
5. Bent push rod(s). 5. Replace push rod(s) as necessary.
6. Worn rocker arms. 6. Replace worn rocker arms and inspect
oil supply to rocker arms.
7. Worn tappets/lash adjusters. 7. Replace hydraulic tappets/hydrauliclash
adjusters.
8. Worn valve guides. 8. Ream and install new valves with
oversize stems.
9. Excessive runout of valve seats
on valve faces.9. Grind valve seats and valves.
CONDITION POSSIBLE CAUSES CORRECTION
CONNECTING ROD
NOISE1. Insufficient oil supply. 1. Check engine oil level.
2. Low oil pressure. 2. Check engine oil level. If OK, perform oil
pressure test. Inspect oil pump relief valve
and spring. (Refer to 9 - ENGINE/
LUBRICATION - DIAGNOSIS AND
TESTING).
3. Thin or diluted oil. 3. Change oil and filter.
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 journals.
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. If OK, perform oil
pressure test. Inspect oil pump relief valve
and spring. (Refer to 9 - ENGINE/
LUBRICATION - DIAGNOSIS AND
TESTING).
3. Thin or diluted oil. 3. Change oil and filter.
4. Excessive bearing clearance. 4. Measure bearings for correct clearance.
Repair as necessary.
5. Excessive end play. 5. Check No. 3 bearing for wear on flanges.
6. Crankshaft journal out-of-round
and/or worn.6. Grind journals or replace crankshaft.
7. Loose flywheel. 7. Inspect crankshaft, flywheel, and bolts for
damage. Tighten bolts to correct torque.
OIL PRESSURE DROP 1. Low oil level. 1. Check oil level and fill if necessary.
2. Faulty oil pressure sending unit. 2. Replace sending unit.
3. Clogged oil filter. 3. Install new oil filter.
4. Worn oil pump. 4. Replace worn gears or oil pump
assembly.
5. Thin or diluted oil. 5. Change oil to correct viscosity.
6. Excessive bearing clearance. 6. Measure bearings for correct clearance.
7. Oil pump relief valve stuck. 7. Remove relief valve. Inspect valve and
spring. Replace as necessary.
8. Oil pump pick up tube restricted,
cracked, or damaged.8. Remove oil pan and inspect oil pump
pick up tube. Clean or replace as
necessary.
9. Oil pump cover loose, warped, or
cracked.9. Inspect/tighten cover screws or install
new oil pump, if necessary.
OIL LEAKS 1. Misaligned or deteriorated
gaskets.1. Replace gaskets.
2. Loose fastener, broken or porous
component.2. Tighten, repair or replace component.