
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐENGINE DIAGNOSIS - MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
LUBRICATING OIL
PRESSURE LOW1. Low oil level. 1. (a) Check and fill with clean engine oil.
(b) Check for a severe external oil leak that
could reduce the pressure.
2. Oil viscosity thin, diluted or wrong
specification.2. (a) Verify the correct engine oil is being
used. (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
2. (b) Look for reduced viscosity from fuel
dilution.
3. Improperly operating pressure
switch/gauge.3. Verify the pressure switch is functioning
correctly. If not, replace switch/gauge.
4. Relief valve stuck open. 4. Check/replace valve.
6. If cooler was replaced, shipping
plugs may have been left in cooler6. Check/remove shipping plugs.
7. Worn oil pump. 7. Check and replace oil pump.
8. Suction tube loose or seal leaking. 8. Check and replace seal.
9. Loose main bearing cap. 9. Check and install new bearing. Tighten
cap to proper torque.
10. Worn bearings or wrong bearings
installed.10. Inspect and replace connecting rod or
main bearings. Check and replace directed
piston cooling nozzles.
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.
DRENGINE 5.9L DIESEL 9 - 233
ENGINE 5.9L DIESEL (Continued)

DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION/LEAKAGE TESTS
CYLINDER COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure batteries are completely charged and the
engine starter motor is in good operating condition.
Otherwise, the indicated compression pressures may
not be valid for diagnostic purposes.
(1) Disconnect the fuel inlet line to the fuel trans-
fer pump. Plug the fuel line from the fuel tank.
(2) Start the engine and idle until the engine stalls
(runs out of fuel).
(3) Disconnect all three injector wire harness con-
nectors at the rocker housing.
(4) Remove the breather cover and cylinder head
cover.
(5) 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 cyl-
inder being tested.
(6) Remove the exhaust rocker lever.
(7) Use Tool 9010 to remove the injector and cop-
per sealing washer.
(8) Install the exhaust rocker lever and torque to
36 N´m (27 ft. lbs.).
(9) Cover the remaining rocker levers with clean
shop towels to prevent any oil splatter under the
hood.
(10) Place a rag over the compression test tool fit-
ting. Crank the engine for 2±3 seconds to purge any
fuel that may have drained into the cylinder when
the injector was removed.
(11) Connect the compression test gauge.
(12) Crank the engine for 5 seconds and record the
pressure reading. Repeat this step three times and
calculate the average of the three readings.
NOTE: The minimum cylinder pressure is 350 psi.
Cylinder pressure should be within 20% from cylin-
der to cylinder.
(13) Combustion pressure leakage can be checked
if cylinder pressure is below the specification. Per-
form the leakage test procedure on each cylinder
according to the tester manufacturer instructions.
(14) Upon completion of the test check an erase
any engine related fault codes.
CYLINDER COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss
(1) Start and operate the engine until it attains
normal operating temperature.
(2) Remove the breather cover and cylinder head
cover.
(3) Disconnect all three injector wire harness con-
nectors at the rocker housing.
(4) Bring the cylinder to be tested to TDC.
(5) Remove the high pressure fuel line between the
cylinder head and the fuel rail for the cylinder to be
tested.
(6) Install capping Tool 9011 onto the rail.
(7) Remove the high pressure connector nut and
high pressure connector with Tool 9015.
(8) Remove the exhaust and intake rocker lever.
(9) Use Tool 9010 to remove the injector and cop-
per sealing washer.
(10) Install compression test Tool 9007 into the
injector bore.
(11) Connect the leakage tester and perform the
leakage test procedure on each cylinder according to
the tester manufacturer's instructions.
(12) Upon completion of the test check and erase
any engine related fault codes.
STANDARD PROCEDURE
STANDARD PROCEDURE - FORM-IN-PLACE
GASKETS AND SEALERS
There are numerous places where form-in-place
gaskets are used on the engine. Care must be taken
when applying form-in-place gaskets to assure
obtaining the desired results.Do not use form-in-
place gasket material unless specified.Bead size,
continuity, and location are of great importance. Too
thin a bead can result in leakage while too much can
result in spill-over which can break off and obstruct
fluid feed lines. A continuous bead of the proper
width is essential to obtain a leak-free gasket.
There are numerous types of form-in-place gasket
materials that are used in the engine area. Mopart
Engine RTV GEN II, MopartATF-RTV, and Mopart
Gasket Maker gasket materials, each have different
properties and can not be used in place of the other.
MOPARtENGINE RTV GEN II
MopartEngine RTV GEN II is used to seal com-
ponents exposed to engine oil. This material is a spe-
cially designed black silicone rubber RTV that
retains adhesion and sealing properties when
exposed to engine oil. Moisture in the air causes the
DRENGINE 5.9L DIESEL 9 - 239
ENGINE 5.9L DIESEL (Continued)

ENGINE DATA PLATE
DESCRIPTION
The engine data plate contains specific information
that is helpful to servicing and obtaining parts for
the engine. The data plate can be found affixed to the
breather cover on the left side of the engine. Informa-
tion that can be found on the data plate includes:
²Date of Engine Manufacture
²Engine Serial Number
²Control Parts List (CPL)
²Engine Rated Horsepower
²Engine Firing Order
²Engine Displacement
²Valve Lash Reset Specifications
If the engine data plate is missing or not legible,
the engine serial number is used for engine identifi-
cation. The engine serial number is stamped on the
right side of the block, on top of the oil cooler cavity
(Fig. 5).
AIR CLEANER ELEMENT
REMOVAL
Testing Air Cleaner Element using Filter MinderŸ
Do not attempt to unnecessarily remove top
of air cleaner housing for air cleaner element
inspection on diesel engines.
The air cleaner (filter) housing is equipped with an
air Filter MinderŸ gauge (Fig. 6). This air flow
restriction gauge will determine when air cleaner ele-
ment is restricted and should be replaced.
The Filter MinderŸ consists of a diaphragm and
calibrated spring sealed inside of a plastic housing
(Fig. 7). A yellow colored disc attached to diaphragm
moves along a graduated scale on side of Filter
Minder. After the engine has been shut off, a ratch-
eting device located within Filter Minder will hold
yellow disc at highest restriction that air cleaner ele-
ment has experienced. A drop in air pressure due toan 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 (Fig. 7) has
reached red colored zone on graduated scale, air
cleaner element should be replaced. Refer to Removal
/ Installation.
Resetting Filter Minder:After air cleaner (filter)
element has been replaced, press rubber button on
top of Filter Minder (Fig. 7). 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, element 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 got-
ten 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.
Fig. 5 Engine Serial Number Location
Fig. 6 5.9L DIESEL AIR CLEANER - FILTER
MINDERŸ
1 - CLIPS
2 - FILTER COVER
3 - FILTER MINDERŸ
4 - INLET AIR TEMPERATURE/ PRESSURE SENSOR
5 - FILTER HOUSING
9 - 248 ENGINE 5.9L DIESELDR

CLEANINGÐPUSHRODS
Clean the pushrods in a suitable solvent. Rinse in
hot water and blow dry with compressed air. If nec-
essary, use a wire brush or wheel to remove stubborn
deposits.
INSPECTION
INSPECTION - CYLINDER HEAD
Inspect the cylinder head for cracks in the combus-
tion surface. Pressure test any cylinder head that is
visibly cracked. A cylinder head that is cracked
between the injector bore and valve seat can be pres-
sure tested and reused if OK; however, if the crack
extendsintothe valve seat insert bore, the cylinder
headmustbe replaced.
Visually inspect the cylinder block and head com-
bustion surfaces for localized dips or imperfections.
Check the cylinder head and block combustion sur-
faces for overall out-of-flatness. If either the visual or
manual inspection exceeds the limits, then the head
or block must be surfaced.
Check the top surface for damage caused by the
cylinder head gasket leaking between cylinders.
Inspect the block and head surface for nicks, ero-
sion, etc.
Check the head distortion. Maximum overall vari-
ation end to end is 0.305 mm (0.012 inch) (Fig. 13),
and maximum overall variation side to side 0.076
mm ( .003 in.).
DO NOT proceed with the in-chassis overhaul if
the cylinder head or block surface is damaged or not
flat (within specifications).
Check block surface for distortion. Maximum vari-
ation end-to-end is 0.076 mm ( .003 in.), side-to-side
0.051 mm (.002).Visually inspect the cylinder head bolts for dam-
aged threads, corroded/pitted surfaces, or a reduced
diameter due to bolt stretching.
If the bolts are not damaged, their ªfree lengthº
should be measured using the cap screw stretch
gauge provided with the replacement head gasket.
Place the head of the bolt against the base of the slot
and align the bolt with the straight edge of gauge
(Fig. 14). If the end of the bolt touches the foot of the
gauge, the boltmustbe discarded.The maximum
bolt free length is 132.1 mm (5.200 in.).
INSPECTIONÐCROSSHEADS
Inspect the crossheads for cracks and/or excessive
wear on rocker lever and valve tip mating surfaces
(Fig. 15). Replace any crossheads that exhibit abnor-
mal wear or cracks.
Fig. 13 Cylinder Head Combustion Deck Face
1 - STRAIGHT EDGE
2 - FEELER GAUGE
Fig. 14 Head Bolt Stretch Gauge
Fig. 15 Inspecting Crosshead for Cracks
9 - 252 ENGINE 5.9L DIESELDR
CYLINDER HEAD (Continued)

INSTALLATION
(1) Install new valve seals. The yellow seals are for
the intake valves and the green seals are for the
exhaust valves.
(2) Install the valves in their original postion. The
exhaust valves are identified by a dimple on the
valve head (Fig. 31).
(3) Install the valve springs and retainer.
(4) Install the valve spring compressor tool 8319±A
as shown in (Fig. 22) and (Fig. 23).
(5) Compress the valve springs and install the
valve retaining locks (Fig. 24).
(6) Remove the compressor and repeat the proce-
dure on the remaining cylinders.
(7) Install new o-ring and sealing washer on injec-
tor.
(8) Lubricate o-ring and injector bore.
(9) Verify sealing washer (shim) was removed with
old injector.
(10) Install injector Refer to (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/FUEL INJECTOR -
INSTALLATION).
(11) Install the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - INSTALLATION).
STANDARD PROCEDURE - VALVE LASH
ADJUSTMENT AND VERIFICATION
NOTE: To obtain accurate readings, valve lash mea-
surements AND adjustments should only be per-
formed when the engine coolant temperature is less
than 60É C (140É F).
The 24±valve overhead system is a ªlow-mainte-
nanceº design. Routine adjustments are no longer
necessary, however, measurement should still takeplace when trouble-shooting performance problems,
or upon completion of a repair that includes removal
and installation of the valve train components or
injectors.
(1) Disconnect battery negative cables.
(2) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(3) Using the crankshaft barring tool #7471±B,
rotate crankshaft to align damper TDC mark to
12:00 o'clock position.
(a) If both number one cylinder rocker levers are
loose, continue to next step.
(b) If both number one clylinder rocker levers
are not loose, rotate crankshaft 360 degrees.
(4) With the engine in this position, valve lash can
be measured at the following rocker arms:INTAKE
1±2±4 / EXHAUST 1±3±5. Measure the valve lash by
inserting a feeler gauge between the rocker arm
socket and crosshead (Fig. 32). Refer to VALVE
LASH LIMIT CHART for the correct specifications. If
the measurement fallswithinthe limits, adjust-
ment/resettingis notnecessary. If measurement
finds the lashoutsideof the limits, adjustment/re-
settingisrequired.
VALVE LASH LIMIT CHART
INTAKE EXHAUST
0.152 mm ( 0.006 in.)
MIN.0.381 mm (0.015 in.)
MIN.
0.381 mm (0.015 in.)
MAX.0.762 mm (0.030 in.)
MAX.
note:
If measured valve lash falls within these
specifications, no adjustment/reset is necessary.
Engine operation within these ranges has no adverse
affect on performance, emissions, fuel economy or
level of engine noise.
(5) If adjustment/resetting is required, loosen the
lock nut on rocker arms and turn the adjusting screw
until the desired lash is obtained:
²INTAKE0.254 mm (0.010 in.)
²EXHAUST0.508 mm (0.020 in.) Tighten the
lock nut to 24 Nm (18 ft. lbs.) and re-check the valve
lash.
(6) Using the crankshaft barring tool, rotate the
crankshaftone revolution (360É) to align the
damper TDC mark to the 12 o'clock position.
Fig. 31 Valve Identification
1 - INTAKE VALVES
2 - EXHAUST VALVES
DRENGINE 5.9L DIESEL 9 - 259
INTAKE/EXHAUST VALVES & SEATS (Continued)

(7) With the engine in this position, valve lash can
be measured at the remaining rocker arms:INTAKE
3±5±6 / EXHAUST 2±4±6. Use the same method as
above for determining whether adjustment is neces-
sary, and adjust those that are found to be outside of
the limits.
(8) Install the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(9) Connect the battery negative cables.
REMOVAL - VALVE SPRINGS AND SEALS
(1) Disconnect the battery negative cables.
(2) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(3) Disconnect rocker housing injector harness con-
nector. Remove all injector harness solenoid nuts.
(4) Remove injector(s) for cylinder(s) to be serviced.
Refer to Group 14 for injector removal.
(5) Remove the rocker housing.
(6) Remove the rocker arms and crossheads from
the cylinder(s) to be serviced. Mark each component
so they can be installed in their original position.
(7) Using the crankshaft barring tool #7471±B
(Fig. 33), rotate the engine to position the damper
mark in the 12 o'clock position.At this engine posi-
tion, cylinders #1 and #6 can be serviced.
(8) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(9) With the damper TDC mark in the 12 o'clock
position, add a paint mark anywhere on the gear
housing cover next to the crankshaft damper. Place
another mark on the vibration damper in alignment
with the mark you just made on the cover.(10) Divide the crankshaft damper into three
equally sized segments as follows:
(a) Using a tape measure, measure the circum-
ference of the crankshaft damper and divide the
measurement by three (3).
(b) Measure that distance in a counter-clockwise
direction from the first balancer mark and place
another mark on the balancer.
(c) From the second damper mark, again mea-
sure in a counter-clockwise direction and place a
mark on the damper at the same distance you
measured when placing the second damper mark.
The damper should now be marked in three
equally spaced locations and the damper TDC
mark should be in the 12 o'clock position.
(d) Remove injectors, fuel lines, and high pres-
sure connectors for every cylinder that requires
repair.
(11) Compress the valve springs at cyls. #1 and #6
as follows:
(a) Install the valve spring compressor mounting
base as shown in (Fig. 34).
(b) Install the top plate, washer, and nut. Using
a suitable wrench tighten the nut (clock-wise) (Fig.
35) to compress the valve springs and remove the
collets.
(c) Rotate the compressor nut counter-clockwise
to relieve tension on springs. Remove spring com-
pressor.
(d) Remove and replace retainers, springs, and
seals as necessary.
(e)Do not rotate the engine until the
springs and retainers are re-installed.
(f) Install seals, springs and retainers. Install
spring compressor, compress valve springs and
install the collets.
Fig. 32 Measuring Valve Lash - Typical
1 - INTAKE
2 - FEELER GAUGE
3 - EXHAUST
Fig. 33 Rotating Engine with Barring Tool - Typical
1 - REAR FLANGE
2 - BARRING TOOL
9 - 260 ENGINE 5.9L DIESELDR
INTAKE/EXHAUST VALVES & SEATS (Continued)

After removing the boring bar, use a honing stone
to chamfer the corner of the repair sleeve(s).
SLEEVE MACHINING DIMENSIONS CHART
ITEM MEASUREMENT
SLEEVE PROTRUSION MIN. - FLUSH WITH
BLOCK
MAX. - 0.050 mm
(0.0019 in.)
SLEEVE DIAMETER 101.956 mm (4.014 in.)
SLEEVE CHAMFER APPROX. 1.25 mm
(0.049 in.) by 15É
A correctly honed surface will have a crosshatch
appearance with the lines at 15É to 25É angles with
the top of the cylinder block. For the rough hone, use
80 grit honing stones. To finish hone, use 280 grit
honing stones.
Finished bore inside dimension is 102.020 0.020
mm (4.0165 0.0008 inch).
A maximum of 1.2 micrometer (48 microinch) sur-
face finish must be obtained.
After finish honing is complete, immediately clean
the cylinder bores with a strong solution of laundry
detergent and hot water.
After rinsing, blow the block dry with compressed
air.
Wipe the bore with a white, lint-free, lightly oiled
cloth. Make sure there is no grit residue present.
Apply a rust-preventing compound if the block will
not be used immediately.
A standard diameter piston and a piston ring set
must be used with a sleeved cylinder bore.
STANDARD PROCEDUREÐCAM BORE REPAIR
For standard bushings, not oversized, maximum
front and rear cam bushing bore diameter is 59.248
mm. (2.3326 in.). DO NOT bore the intermediate cam
bore to the front cam bore oversize dimensions. Max-
imum front and rear camshaft bushing installed
diameter is 54.147 mm. (2.1318 in.). Minimum
installed diameter is 54.083 mm. (2.1293 in.). Maxi-
mum intermediate camshaft bore diameter is 54.164
mm. (2.1324 in.).
A surface finish of 2.3 micrometers (92 microinch)
must be maintained. Not more than 20% of an area
of any one bore may be 3.2 micrometers (126 micro-
inch).
Camshaft bores can be repaired individually. It is
not necessary to repair undamaged cam bores in
order to repair individually damaged cam bores. The
standard front bushing cannot be used to repair
intermediate bores.Install all cam bushings flush or below the front
and rear cam bore surface. The front camshaft bush-
ing should be installed flush with front face of block.
The rear camshaft bushing should be installed flush
with rear face of block. The oil hole must align to
allow a 3.2 mm (0.125 inch) rod to pass through
freely (Fig. 52).
INSPECTION
Measure the combustion deck face using a straight
edge and a feeler gauge (Fig. 53). Cylinder block flat-
ness: End-to-end 0.076 mm ( .003 in.). Maximum
variation side-to-side 0.051 mm (.002 in.).
Inspect for any localized dips or imperfections.
If the surface exceeds the limit, (Refer to 9 -
ENGINE/ENGINE BLOCK - STANDARD PROCE-
DURE).
Fig. 52 Oil Hole Alignment
1 - CAMSHAFT BUSHING
Fig. 53 Combustion Deck Face Measurement
1 - STRAIGHT EDGE
2 - FEELER GAUGE
DRENGINE 5.9L DIESEL 9 - 267
ENGINE BLOCK (Continued)

INSPECTION
Camshaft
(1) Inspect the valve lobes and bearing journals for
cracks, pitting, scoring, or generally excessive wear.
Replace any camshaft that exceeds the allowable lim-
its.
(2) Measure the bearing journals and lobes (Fig.
58).
CAUTION: If Camshaft lobes are worn, requiring
camshaft replacement, it is necessary to replace the
tappets also. (Refer to 9 - ENGINE/ENGINE BLOCK/
SOLID LIFTERS - REMOVAL).
CAMSHAFT DIMENSIONS
CAMSHAFT DIMENSIONS
Journal diameter (No.1 and No.7)
Min. 54.028 mm.
(2.127 in.)
Max. 54.048 mm.
(2.128 in.)
Journal diameter (No.2 through
No.6)
Min. 53.962 mm.
(2.1245 in.)
Max. 54.013 mm.
(2.1265 in.)
Diameter of peak of lobe
Intake
Min. 47.175 mm
(1.857 in.)
Max 47.855 mm.
Exhaust
Min. 45.632 mm.
(1.797 in.)
Max. 46.312 mm.
(1.823 in.)
Camshaft Bushing/Bores
Camshaft bores No. 2±6do notuse a bushing.
(1) Inspect the camshaft bushing and bores for
signs of excessive wear.
(2) Measure the camshaft bushing and bores (Fig.
59) with a telescoping bore gauge and micrometer. If
out of specification, (Refer to 9 - ENGINE/ENGINE
BLOCK/CAMSHAFT & BEARINGS (IN BLOCK) -
REMOVAL).
Fig. 59 Measuring Camshaft Bushing and Bores
Fig. 58 Measuring
1 - VALVE LOBE
2 - CAMSHAFT JOURNAL
9 - 270 ENGINE 5.9L DIESELDR
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)