Oil change DODGE RAM 1500 1998 2.G Service Manual

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL
ENGINE MECHANICAL DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES/LIFTERS 1. High or low oil level in crankcase 1. Check for correct oil level. Adjust
oil level by draining or adding as
needed
2. Thin or diluted oil 2. Change oil. (Refer to 9 -
ENGINE/LUBRICATION/OIL -
STANDARD PROCEDURE)
3. Low oil pressure 3. Check engine oil level. If ok,
Perform oil pressure test. (Refer to
9 - ENGINE/LUBRICATION -
DIAGNOSIS AND TESTING) for
engine oil pressure test/
specifications
4. Dirt in tappets/lash adjusters 4. Clean/replace hydraulic
tappets/lash adjusters
5. Bent push rod(s) 5. Install new push rods
6. Worn rocker arms 6. Inspect oil supply to rocker arms
and replace worn arms as needed
7. Worn tappets/lash adjusters 7. Install new hydraulic tappets/lash
adjusters
8. Worn valve guides 8. Inspect all valve guides and
replace as necessary
9. Excessive runout of valve seats
or valve faces9. Grind valves and seats
CONNECTING ROD 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. (Refer to
9 - ENGINE/LUBRICATION -
DIAGNOSIS AND TESTING) engine
oil pressure test/specifications
3. Thin or diluted oil 3. Change oil to correct viscosity.
(Refer to 9 - ENGINE/
LUBRICATION/OIL - STANDARD
PROCEDURE) for correct
procedure/engine oil specifications
4. Excessive connecting rod
bearing clearance4. Measure bearings for correct
clearance with plasti-gage. Repair
as necessary
5. Connecting rod journal out of
round5. Replace crankshaft or grind
journals
6. Misaligned connecting rods 6. Replace bent connecting rods
9 - 188 ENGINE - 5.7LDR
ENGINE - 5.7L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
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. (Refer to
9 - ENGINE/LUBRICATION -
DIAGNOSIS AND TESTING)
3. Thin or diluted oil 3. Change oil to correct viscosity.
4. Excessive main bearing
clearance4. Measure bearings for correct
clearance. Repair as necessary
5. Excessive end play 5. Check crankshaft thrust bearing
for excessive wear on flanges
6. Crankshaft main journal out of
round or worn6. Grind journals or replace
crankshaft
7. Loose flywheel or torque
converter7. Inspect crankshaft, flexplate/
flywheel and bolts for damage.
Tighten to correct torque
LOW OIL PRESSURE 1. Low oil level 1. Check oil level and fill if
necessary
2. Faulty oil pressure sending unit 2. Install new sending unit
3. Clogged oil filter 3. Install new oil filter
4. Worn oil pump 4. Replace 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 valve to inspect, clean
and reinstall
8. Oil pickup tube loose, broken,
bent or clogged8. Inspect oil pickup tube and pump,
and clean or replace if necessary
9. Oil pump cover warped or
cracked9. Install new oil pump
OIL LEAKS 1. Misaligned or deteriorated
gaskets1. Replace gasket
2. Loose fastener, broken or porous
metal part2. Tighten, repair or replace the part
3. Front or rear crankshaft oil seal
leaking3. Replace seal
4. Leaking oil gallery plug or cup
plug4. Remove and reseal threaded
plug. Replace cup style plug
DRENGINE - 5.7L 9 - 189
ENGINE - 5.7L (Continued)

REMOVAL
(1) Remove the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL).
(2) Compress valve springs using Valve Spring
Compressor Tool special tool # C-3422and adapter
8464.
(3) Remove valve retaining locks, valve spring
retainers, valve stem seals and valve springs.
(4) Before removing valves, remove any burrs from
valve stem lock grooves to prevent damage to the
valve guides. Identify valves to ensure installation in
original location.
INSTALLATION
(1) Clean valves thoroughly. Discard burned,
warped and cracked valves.
(2) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
(3) Measure valve stems for wear. If wear exceeds
0.051 mm (0.002 inch), replace the valve.
(4) Coat valve stems with lubrication oil and insert
them in cylinder head.
(5) If valves or seats are reground, check valve
stem height. If valve is too long, replace cylinder
head.
(6) Install new seals on all valve guides. Install
valve springs and valve retainers.
(7) Compress valve springs with Valve Spring
Compressor Tool special tool # C- 3422and adapter
8464, install locks and release tool. If valves and/or
seats are ground, measure the installed height of
springs. Make sure the measurement is taken from
bottom of spring seat in cylinder head to the bottom
surface of spring retainer.
(8) Install cylinder head (Refer to 9 - ENGINE/
CYLINDER HEAD - INSTALLATION).
ROCKER ARM / ADJUSTER
ASSY
REMOVAL
(1) Remove cylinder head cover.(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL)
(2) Loosen the rocker shafts using the following
sequence:Center, center-left, center-right, left,
right,.
CAUTION: The rocker shaft assemblies are not
interchangeable between intake and exhaust. The
intake rocker arms are marked with an ªIº.
(3) Remove the rocker shafts. Note location for
reassembly.CAUTION: The longer push rods are for the exhaust
side, and the shorter push rods are for intake side.
(4) Remove the pushrods. Note pushrod location
for reassembly.
INSTALLATION
CAUTION: The longer push rods are for the exhaust
side, and the shorter push rods are for intake side.
(1) Install the push rods in the same order as
removed.
CAUTION: Verify that pushrod is installed into
rocker arm and lifter correctly while installing
rocker shaft assembly. Recheck after rocker shaft
has been torqued to specification.
CAUTION: The rocker shaft assemblies are not
interchangeable between intake and exhaust. The
intake rocker arms are marked with the letter ªIº.
(2) Install rocker shaft assemblies in the same
order as removed.
CAUTION: Ensure that hold downs and rocker arms
are not overlapped when torquing bolts.
(3) Tighten the rocker shaft bolts to 22 N´m (195
in. lbs.) torque,using the following sequence:Center,
center-right, center-left, right, left.
CAUTION: DO NOT rotate or crank the engine dur-
ing or immediately after rocker arm installation.
Allow the hydraulic roller tappets adequate time to
bleed down (about 5 minutes).
(4) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
VALVE STEM SEALS
DESCRIPTION
The valve guide seals are made of rubber and
incorporate an integral steel valve spring seat. The
integral garter spring maintains consistent lubrica-
tion control to the valve stems.
DRENGINE - 5.7L 9 - 203
INTAKE/EXHAUST VALVES & SEATS (Continued)

VALVE SPRINGS
REMOVAL
(1) Disconnect negative battery cable.
(2) Remove air cleaner assembly.
(3) Remove air intake resonator.
(4) Remove spark plug cables.
(5) Remove ignition coil connectors (Fig. 6).
(6) Remove ignition coils.
(7) Remove one spark plug.
(8) Remove valve cover.
CAUTION: The piston must be at TDC, and both
valves closed on the cylinder to be serviced.
NOTE: If removing intake valve spring, install spe-
cial tool# 9070, pushrod retaining plate, to retain
the intake pushrods.
(9) Remove exhaust/intake rocker arm shafts.
(10) Install spring compressor, special tool# 9065.
NOTE: All valve springs and seals are removed in
the same manner.(11) Charge cylinder with air.
NOTE: Tap the top of the valve spring retainer to
loosen the spring retainers locks.
(12) Compress valve spring and remove valve
retainer locks.
(13) Release spring compressor and remove valve
spring.
NOTE: The valve springs are interchangeable
between intake and exhaust.
(14) Remove valve seal.
INSTALLATION
(1) Install valve seal.
(2) Install valve spring.
(3) Using special tool# 9065, compress valve spring
and install valve spring retainer and locks.
(4) Release air charge in cylinder.
(5) Remove spring compressor tool # 9065.
CAUTION: Verify that the pushrods are fully seated
into lifter and rocker arm. Recheck after rocker arm
shaft has been torqued to specification.
(6) Install rocker arm shaft and pushrods(Refer to
9 - ENGINE/CYLINDER HEAD/ROCKER ARM /
ADJUSTER ASSY - INSTALLATION).
(7) Tighten the rocker shaft bolts to 22 N´m (195
in. lbs.) torque,using the following sequence:Center,
center-right, center-left, right, left.
(8) Remove special tool# 9070, pushrod retaining
plate, if used.
(9) Install cylinder head cover.
(10) Tighten cylinder head cover bolts and double
ended studs(Refer to 9 - ENGINE/CYLINDER
HEAD/CYLINDER HEAD COVER(S) - INSTALLA-
TION).
(11) Install spark plugs.
(12) Install ignition coil on plug, and torque fas-
teners to 12 N´m (105 in. lbs)
(13) Install ignition coil connectors.
(14) Install spark plug cables.
(15) Install air intake resonator.
(16) Install air cleaner assembly.
(17) Connect negative battery cable.
Fig. 6 IGNITION COIL R/I Ð 5.7L V-8
1 - SLIDE LOCK (SLIDE OUTWARD TO UNLOCK)
2 - SPARK PLUG CABLE (TO OPPOSITE CYLINDER BANK
SPARK PLUG)
3 - RELEASE LOCK / TAB (PUSH HERE)
4 - ELEC. CONNECTOR
5 - IGNITION COIL
6 - COIL MOUNTING BOLTS (2)
7 - SPARK PLUG CABLE (TO OPPOSITE CYLINDER BANK
IGNITION COIL)
9 - 204 ENGINE - 5.7LDR

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/CYLINDER HEAD
COVER(S) - REMOVAL).
(5) Remove rocker arm assembly and push rod-
s(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).
(7) Remove bolt from tappet guide holder.
(8) Remove tappet guide holder.
(9) Pull tappet out of bore with a twisting motion.
If all tappets are to be removed and reused, identify
tappets to ensure installation in original location.
(10) Check camshaft lobes for abnormal wear.
INSTALLATION
(1) Lubricate tappets.
(2) Install tappets in their original positions.
(3)
Install tappet guide holder. Install the tappet
guide holder bolt and tighten to 12 N´m (106 in. lbs.)
torque.
(4) Install cylinder head(Refer to 9 - ENGINE/
CYLINDER HEAD - INSTALLATION).
(5) Install pushrods and rocker arm assembly(Re-
fer to 9 - ENGINE/CYLINDER HEAD/ROCKER
ARM / ADJUSTER ASSY - INSTALLATION).
(6) Install cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(7)
Install intake manifold(Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - INSTALLATION).
(8) Install the air cleaner(Refer to 9 - ENGINE/
AIR INTAKE SYSTEM - INSTALLATION).
(9) Connect the negative cable to the battery.
CAUTION: To prevent damage to valve mechanism,
engine must not be run above fast idle until all
hydraulic tappets have filled with oil and have
become quiet.
(10) Road test vehicle and check for leaks.
PISTON & CONNECTING ROD
DESCRIPTION
CAUTION: Do not use a metal stamp to mark con-
necting rods as damage may result, instead use ink
or a scratch awl.The pistons are made of a high strength aluminum
alloy. Piston skirts are coated with a solid lubricant
(Molykote) to reduce friction and provide scuff resis-
tance. The piston top ring groove and land is anod-
ized. The connecting rods are made of forged
powdered metal, with a ªfractured capº design. A
pressed fit piston pin is used to attach the piston and
connecting rod.
STANDARD PROCEDUREÐPISTON FITTING
(1) To correctly select the proper size piston, a cyl-
inder 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 a point 38.0 mm (1.5 inches) below top of
bore. Start perpendicular (across or at 90 degrees) to
the axis of the crankshaft at point A and then take
an additional bore reading 90 degrees to that at point
B (Fig. 11).
(3) The coated pistons will be serviced with the
piston pin and connecting rod pre-assembled. The
piston-rod assembly is specific for the left cylinder
bank ( odd numbered) and the right cylinder bank (
even numbered) and must not be interchanged.
(4) The coating material is applied to the piston
after the final piston machining process. Measuring
the outside diameter of a coated piston will not pro-
vide accurate results (Fig. 10). Therefore measuring
the inside diameter of the cylinder bore with a dial
Bore Gauge isMANDATORY. To correctly select the
proper size piston, a cylinder bore gauge capable of
reading in 0.003 mm (.0001 in.) increments is
required.
Fig. 10 MOLY COATED PISTON
1 - MOLY COATED
2 - MOLY COATED
DRENGINE - 5.7L 9 - 211
HYDRAULIC TAPPETS (Continued)

(5) Piston installation into the cylinder bore
requires slightly more pressure than that required
for non-coated pistons. The bonded coating on the
piston will give the appearance of a line-to-line fit
with the cylinder bore.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the following components:
²Oil pan and gasket/windage tray (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - REMOVAL).
²Cylinder head covers (Refer to 9 - ENGINE/
CYLINDER HEAD/CYLINDER HEAD COVER(S) -
REMOVAL) and (Refer to 9 - ENGINE/CYLINDER
HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
²Timing chain cover (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- REMOVAL).
²Cylinder head(s) (Refer to 9 - ENGINE/CYLIN-
DER HEAD - REMOVAL) and (Refer to 9 - ENGINE/
CYLINDER HEAD - REMOVAL).
(3) If necessary, remove top ridge of cylinder bores
with a reliable ridge reamer before removing pistons
from cylinder block.Be sure to keep tops of pis-
tons covered during this operation.Pistons and
connecting rods must be removed from top of cylinder
block. When removing piston and connecting rod
assemblies from the engine, rotate crankshaft so the
each connecting rod is centered in cylinder bore.CAUTION: DO NOT use a number stamp or a punch
to mark connecting rods or caps, as damage to
connecting rods could occur
NOTE: Connecting rods and bearing caps are not
interchangeable and should be marked before
removing to ensure correct reassembly.
(4)
Mark connecting rod and bearing cap positions
using a permanent ink marker or scribe tool (Fig. 12).
CAUTION: Care must be taken not to damage the
fractured rod and cap joint face surfaces, as engine
damage may occur.
(5) Remove connecting rod cap. Install Special Tool
8507 Connecting Rod Guides into the connecting rod
being removed. Remove piston from cylinder bore.
Repeat this procedure for each piston being removed.
CAUTION: Care must be taken not to nick crank-
shaft journals, as engine damage may occur
(6) Immediately after piston and connecting rod
removal, install bearing cap on the mating connect-
ing rod to prevent damage to the fractured cap and
rod surfaces.
(7) Carefully remove piston rings from piston(s),
starting from the top ring down.
CLEANING
CAUTION: DO NOT use a wire wheel or other abra-
sive cleaning devise to clean the pistons or con-
necting rods. The pistons have a Moly coating, this
coating must not be damaged.
(1) Using a suitable cleaning solvent clean the pis-
tons in warm water and towel dry.
(2) Use a wood or plastic scraper to clean the ring
land grooves.
CAUTION: DO NOT remove the piston pin from the
piston and connecting rod assembly.
Fig. 11 BORE GAUGE - TYPICAL
1 - FRONT
2 - BORE GAUGE
3 - CYLINDER BORE
4-38MM
(1.5 in)
Fig. 12 IDENTIFY CONN ROD TO CYLINDER
9 - 212 ENGINE - 5.7LDR
PISTON & CONNECTING ROD (Continued)

INSPECTION
Check the connecting rod journal for excessive
wear, taper and scoring (Refer to 9 - ENGINE/EN-
GINE BLOCK/CONNECTING ROD BEARINGS -
STANDARD PROCEDURE).
Check the connecting rod for signs of twist or bend-
ing.
Check the piston for taper and elliptical shape
before it is fitted into the cylinder bore (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON & CONNECT-
ING ROD - STANDARD PROCEDURE).
Check the piston for scoring, or scraping marks in
the piston skirts. Check the ring lands for cracks
and/or deterioration.
INSTALLATION
(1) Before installing piston and connecting rod
assemblies into the bore, install the piston rings(Re-
fer to 9 - ENGINE/ENGINE BLOCK/PISTON RINGS
- STANDARD PROCEDURE).
(2) Immerse the piston head and rings in clean
engine oil. Position a ring compressor over the piston
and rings. Tighten ring compressor.Ensure posi-
tion of rings do not change during this opera-
tion.
(3) Position bearing onto connecting rod. Lubricate
bearing surface with clean engine oil.
(4) Install Special Tool 8507 Connecting Rod
Guides into connecting rod bolt threads.
(5) The pistons are marked on the piston pin bore
surface with an raised ªFº or arrow on top of piston
indicating installation position. This mark must be
pointing toward the front of engine on both cylinder
banks.
(6) Wipe cylinder bore clean and lubricate with
engine oil.
(7) Rotate crankshaft until connecting rod journal
is on the center of cylinder bore. Insert rod and pis-
ton into cylinder bore and carefully position connect-
ing rod guides over crankshaft journal.
(8) Tap piston down in cylinder bore using a ham-
mer handle. While at the same time, guide connect-
ing rod into position on rod journal.
CAUTION: Connecting Rod Bolts are Torque to
Yield Bolts and Must Not Be Reused. Always
replace the Rod Bolts whenever they are loosened
or removed.
(9) Lubricate rod bolts and bearing surfaces with
engine oil. Install connecting rod cap and bearing.
Tighten bolts to 21 N´m (15 ft. lbs.) plus a 90É turn.
(10) Install the following components:
²Cylinder head(s). (Refer to 9 - ENGINE/CYLIN-
DER HEAD - INSTALLATION).²Cylinder head covers (Refer to 9 - ENGINE/
CYLINDER HEAD/CYLINDER HEAD COVER(S) -
INSTALLATION).
²Install the intake manifold.
²Oil pan and gasket/windage tray. (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
(11) Fill crankcase with proper engine oil to cor-
rect level.
(12) Connect negative cable to battery.
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING
Before reinstalling used rings or installing new
rings, the ring clearances must be checked.
(1) Wipe the cylinder bore clean.
(2) Insert the ring in the cylinder bore.
NOTE: The ring gap measurement must be made
with the ring positioned at least 12mm (0.50 inch.)
from bottom of cylinder bore.
(3) Using a piston, to ensure that the ring is
squared in the cylinder bore, slide the ring downward
into the cylinder.
(4) Using a feeler gauge check the ring end gap
(Fig. 13). Replace any rings not within specification.
PISTON RING SIDE CLEARANCE
NOTE: Make sure the piston ring grooves are clean
and free of nicks and burrs.
Fig. 13 Ring
1 - FEELER GAUGE
DRENGINE - 5.7L 9 - 213
PISTON & CONNECTING ROD (Continued)

minutes before checking oil level. Checking engine oil
level on a cold engine is not accurate.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable levels are indicated between the ADD
and SAFE marks on the engine oil dipstick.
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately five
minutes for oil to settle to bottom of crankcase,
remove engine oil dipstick.
(3) Wipe dipstick clean.
(4) Install dipstick and verify it is seated in the
tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the ADD mark on
dipstick.
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals
described in Maintenance Schedules(Refer to LUBRI-
CATION & MAINTENANCE/MAINTENANCE
SCHEDULES - DESCRIPTION).
Run engine until achieving normal operating tem-
perature.
(1) Position the vehicle on a level surface and turn
engine off.
(2) Hoist and support vehicle on safety stands.
(3) Remove oil fill cap.
(4) Place a suitable drain pan under crankcase
drain.
(5) Remove drain plug from crankcase and allow
oil to drain into pan. Inspect drain plug threads for
stretching or other damage. Replace drain plug if
damaged.
(6) Install drain plug in crankcase. Torque to 34
N´m ( 25 ft. lbs.).
(7) Lower vehicle and fill crankcase with specified
type and amount of engine oil described in this sec-
tion.
(8) Install oil fill cap.
(9) Start engine and inspect for leaks.
(10) Stop engine and inspect oil level.
USED ENGINE OIL DISPOSAL
Care should be exercised when disposing used
engine oil after it has been drained from a vehicle
engine. Refer to the WARNING at beginning of this
section.
OIL FILTER
REMOVAL
All engines are equipped with a high quality full-
flow, disposable type oil filter. DaimlerChrysler Cor-
poration recommends a Mopartor equivalent oil
filter be used.
(1) Position a drain pan under the oil filter.
(2) Using a suitable oil filter wrench loosen filter.
(3) Rotate the oil filter counterclockwise to remove
it from the cylinder block oil filter boss.
(4) When filter separates from cylinder block oil
filter boss, tip gasket end upward to minimize oil
spill. Remove filter from vehicle.
NOTE: Make sure filter gasket was removed with fil-
ter.
(5) With a wiping cloth, clean the gasket sealing
surface of oil and grime.
INSTALLATION
(1) Lightly lubricate oil filter gasket with engine
oil.
(2) Thread filter onto adapter nipple. When gasket
makes contact with sealing surface, (Fig. 29) hand
tighten filter one half turn, or 180É,do not over
tighten.
(3) Add oil, verify crankcase oil level and start
engine. Inspect for oil leaks.
Fig. 29 Oil Filter Sealing Surface - Typical
1 - SEALING SURFACE
2 - RUBBER GASKET
3 - OIL FILTER
DRENGINE - 5.7L 9 - 223
OIL (Continued)

NOTE: The 5.7 Oil pump is released as an assem-
bly. There are no DaimlerChrysler part numbers for
Sub-Assembly components. In the event the oil
pump is not functioning or out of specification it
must be replaced as an assembly.
INSTALLATION
(1) Position the oil pump onto the crankshaft and
install the 4 oil pump retaining bolts.(2) Tighten the oil pump retaining bolts to 28 N´m
(250 in. lbs.).
(3) Install the timing chain cover(Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(4) Install the pick-up tube and oil pan(Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
INTAKE MANIFOLD
DESCRIPTION
The intake manifold is made of a composite mate-
rial 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 manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT 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.
Fig. 30 Measuring Outer Rotor Clearance
1 - FEELER GAUGE
2 - OUTER ROTOR
Fig. 31 Measuring Clearance Between Rotors -
Typical
1 - OUTER ROTOR
2 - FEELER GAUGE
3 - INNER ROTOR
Fig. 32 Measuring Clearance Over Rotors - Typical
1 - STRAIGHT EDGE
2 - FEELER GAUGE
DRENGINE - 5.7L 9 - 225
OIL PUMP (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
2. 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. 5. 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.
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.
9 - 234 ENGINE 5.9L DIESELDR
ENGINE 5.9L DIESEL (Continued)