1998 DODGE RAM 1500 Rough idle

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either per-
formance (e.g., engine idles rough and stalls) or
mechanical (e.g., a strange noise).
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING) - PERFORMANCE and (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)ÐMECHANICAL for
possible causes and corrections of malfunctions.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
DIAGNOSIS AND TESTING) and (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION - DIAGNOSIS
AND TESTING) for the fuel system diagnosis.Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following diagnosis:
²Cylinder Compression Pressure Test (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).
²Cylinder Combustion Pressure Leakage Test
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING).
²Engine Cylinder Head Gasket Failure Diagnosis
(Refer to 9 - ENGINE/CYLINDER HEAD - DIAGNO-
SIS AND TESTING).
²Intake Manifold Leakage Diagnosis (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
DIAGNOSIS AND TESTING).
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
6. Dirt or water in fuel system. 6. Clean system and replace fuel
filter.
7. Faulty fuel pump, relay or wiring. 7. Repair or replace as necessary.
DRENGINE - 5.7L 9 - 183
ENGINE - 5.7L (Continued)

CONDITION POSSIBLE CAUSE CORRECTION
ENGINE STALLS OR ROUGH IDLE 1. Idle speed set to low. 1. (Refer to 14 - FUEL SYSTEM/
FUEL INJECTION/IDLE AIR
CONTROL MOTOR - REMOVAL).
2. Idle mixture too lean or too rich. 2. Refer to Powertrain Diagnosis
Information.
3. Vacuum leak. 3. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
5. Incorrect engine timing. 5. (Refer to 9 - ENGINE/VALVE
TIMING - STANDARD PROCEDURE).
1. ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped spark
plugs.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
2. Dirt or water in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/FUEL PUMP -
DIAGNOSIS AND TESTING).
4. Blown cylinder head gasket. 4. Replace cylinder head gasket.
5. Low compression. 5. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
6. Burned, warped or pitted valves. 6. Replace as necessary.
7. Plugged or restricted exhaust
system.7. Inspect and replace as necessary.
8. Faulty coil. 8. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
1. ENGINE MISSES ON
ACCELERATION1. Spark plugs dirty or incorrectly
gapped.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
2. Dirt in fuel system. 2. Clean fuel system.
3. Burned, warped or pitted valves. 3. Replcae as necessary.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
1. ENGINE MISSES AT HIGH SPEED 1. Spark plugs dirty or incorrectly
gapped.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
2. Faulty coil. 2. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
3. Dirt or water in fuel system. 3. Clean system and replace fuel
filter.
9 - 184 ENGINE - 5.7LDR
ENGINE - 5.7L (Continued)

VALVE SPRING
DESCRIPTION SPECIFICATION
Spring Force (Valve
Closed)
Intake and Exhaust 422.0 N @ 46.0 mm
(95lbs. @ 1.81 in.)
Spring Force (Valve
Open)
Intake and Exhaust @ 33.5 mm
Number of Coils
Intake and Exhaust 7.4
Wire Diameter
Intake and Exhaust 5.39 ý 4.52 mm
(0.212 - 0.177 in.)
Installed Height (Spring
Seat to Bottom of
Retainer)
Intake and Exhaust 46.0 mm (1.81 in.)
OIL PUMP
DESCRIPTION SPECIFICATION
Clearance Over Rotors
(MAX)0.095 mm (0.0038 in.)
Outer Rotor to Pump
Body Clearance (MAX).235 mm (.009 in.)
Tip Clearance Between
Rotors (MAX)0.150 mm (0.006 in.)
OIL PRESSURE
SPECIFICATION SPECIFICATION
At Curb Idle Speed
(MIN)*25 kPa (4 psi)
@ 3000 rpm 170 - 758 kPa (25 - 110
psi)
* CAUTION: If pressure is zero at curb idle, DO
NOT run engine
TORQUE
TORQUE CHART 5.7L ENGINE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Block Pipe Plugs
(1/4 NPT)20 Ð 177
(3/8 NPT) 27 Ð 240
Camshaft SprocketÐBolt 122 90 Ð
Camshaft Tensioner
PlateÐBolts28 Ð 250
Timing Chain Case CoverÐ
Bolts28 Ð 250
Lifting Stud 55 40 Ð
Connecting Rod CapÐBolts 21
plus
90É
Turn15
plus
90É
TurnÐ
Main Bearing CapÐBolts
M-1227
plus
90É
TurnÐÐ
Crossbolts
M-828 Ð Ð
Cylinder HeadÐBolts
M-12 Bolts
Step 1 34 25 Ð
Step 2 54 40 Ð
Step 3 Turn
90ÉTurn
90ÉÐ
M-8 Bolts Ð
Step 1 20 15 Ð
Step 2 34 25 Ð
Cylinder Head CoverÐBolts 8 Ð 70
Exhaust Manifold to Cylinder
Head25 Ð 220
Flexplate to crankshaftÐBolts 95 70 Ð
Flywheel to crankshaftÐBolts 75 55 Ð
Front InsulatorÐThrough
bolt/nut95 70 Ð
Front Insulator to Support
Bracket
ÐStud Nut (4WD) 41 30 Ð
ÐThrough Bolt/Nut (4WD) 102 75 Ð
Front Insulator to BlockÐ
Bolts (2WD)95 70 Ð
DRENGINE - 5.7L 9 - 195
ENGINE - 5.7L (Continued)

INSTALLATION
(1) Throughly clean all gasket resdue from the
engine block.
(2) Use extream care and clean all gasket resdue
from the retainer.
(3) Position the gasket onto the retainer.
(4) Position the retainer onto the engine block.
(5) Install the retainer mounting bolts. Tighten the
bolts to 15 N´m (132 in. lbs.) using a crisscross pat-
tern, starting with the bolt on the lower right.
(6) Install a new rear seal(Refer to 9 - ENGINE/
ENGINE BLOCK/CRANKSHAFT OIL SEAL - REAR
- INSTALLATION).
(7) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(8) Install the drive plate / flywheel.
(9) Install the transmission.
(10) Check and verify engine oil level.
(11) Start engine and check for leaks.
FLEX PLATE
REMOVAL
(1) Remove the transmission.
(2) Remove the bolts and flexplate.
INSTALLATION
(1) Position the flexplate or flywheel onto the
crankshaft and install the bolts hand tight.
(2)For automatic transmissions:Tighten the
flexplate retaining bolts to 95 N´m (70 ft. lbs.).
(3)For manual transmissions:Tighten the fly-
wheel retaining bolts to 75 N´m (55 ft. lbs.).
(4) Install the transmission.
HYDRAULIC TAPPETS
DIAGNOSIS AND TESTING - 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 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 con-
ditions 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.
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 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 usu-
ally 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, 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 excessive
leak-down around the unit plunger, or by the plunger
partially sticking in the tappet body cylinder. The tap-
pet should be replaced. A heavy click is caused by a tap-
pet 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 clear-
ance 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 mak-
ing the noise. If more than one tappet seems to be
noisy, it's probably not the tappets.
9 - 210 ENGINE - 5.7LDR
CRANKSHAFT REAR OIL SEAL RETAINER (Continued)

(8) Torque the (3) bolts that attach the front axle
to the left engine bracket to 101 N´m (75 ft. lbs.).
(9) Install the engine oil filter, if removed.
(10) Install the front crossmember(Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - INSTALLATION).
(11) Install the skid plate.
(12) Lower the vehicle.
(13) Reconnect the negative battery cable.
REAR MOUNT
REMOVAL
(1) Raise the vehicle on a hoist.
(2) Using a suitable jack, support transmission.
(3) Remove the nuts from the transmission mount
(Fig. 26).
(4) Remove the two bolts that attach the transmis-
sion mount to the engine bracket.
(5) Raise the transmission enough to remove the
mount from the crossmember.
(6) Remove the mount.
INSTALLATION
NOTE: Threadlocking compound must be applied to
the bolts before installation.(1) Install the two bolts that attach the transmis-
sion mount to the transmission bracket.
(2) Torque the bolts to 61N´m (45 ft.lbs.) torque.
(3) Lower the transmission so the transmission
mount rests on the crossmember, and the studs of
the transmission mount are aligned in the slots in
the crossmember.
(4) Install the nuts onto the transmission mount
studs through the crossmember access slot.
(5) Torque the nuts to 54N´m (40 ft. lbs.).
LUBRICATION
DESCRIPTION
The lubrication system (Fig. 27) is a full flow fil-
tration pressure feed type.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - CHECKING
ENGINE OIL PRESSURE
(1) Remove oil pressure sending unit and install
gauge assembly C-3292.
(2) Run engine until thermostat opens.
(3) Oil Pressure:
²Curb Idle±25 kPa (4 psi) minimum
²3000 rpm±170 - 758 kPa (25 - 110 psi)
(4) If oil pressure is 0 at idle, shut off engine.
Check for a clogged oil pick-up screen or a pressure
relief valve stuck open.
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair per service manual instructions.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.If the oil leak source is not pos-
itively identified at this time, proceed with the air
leak detection test method.
Fig. 26 TRANSMISSION MOUNT
1 - MOUNT
2 - CROSSMEMBER
3 - NUT
4 - BOLT
9 - 220 ENGINE - 5.7LDR
FRONT MOUNT (Continued)

REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove resonator assembly and air inlet hose.
(3) Disconnect electrical connectors for the follow-
ing components:
²Manifold Absolute Pressure (MAP) Sensor
²Intake Air Temperature (IAT) Sensor
²Throttle Position (TPS) Sensor
²Coolant 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 SYS-
TEM/FUEL DELIVERY - STANDARD PROCE-
DURE).
(8) Remove intake manifold retaining fasteners in
a crisscross pattern starting from the outside bolts
and ending at the middle bolts.
(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 dur-
ing inspection, the intake manifold must be
replaced.
Before installing the intake manifold thoroughly
clean the mating surfaces. Use a suitable cleaning
solvent, then air dry.
INSPECTION
(1) Inspect the intake sealing surface for cracks,
nicks and distortion.
(2) Inspect the intake manifold vacuum hose fit-
tings for looseness or blockage.
(3) Inspect the manifold to throttle body mating
surface for cracks, nicks and distortion.
INSTALLATION
(1) Install intake manifold seals.
(2) Position intake manifold and IAFM.
(3) Install intake manifold retaining bolts, and
tighten in sequence from the middle bolts towards
the outside in a crisscross pattern. Torque fasteners
to 12 N´m (105 in. lbs.).
(4) Connect electrical connectors for the following
components:
²Manifold Absolute Pressure (MAP) Sensor
²Intake Air Temperature (IAT) Sensor²Throttle Position (TPS) Sensor
²Coolant Temperature (CTS) Sensor
²Idle Air Control (IAC) Motor
(5) Install generator.
(6) Install A/C compressor.
(7) Connect Brake booster hose and Positive crank-
case ventilation (PCV) hose.
(8) Install resonator assembly and air inlet hose.
(9) Connect negative cable to battery.
EXHAUST MANIFOLD
DESCRIPTION
The exhaust manifolds are log style with a pat-
ented flow enhancing design to maximize perfor-
mance. The exhaust manifolds are made of high
silicon molybdenum cast iron. A perforated core
graphite exhaust manifold gasket is used to improve
sealing to the cylinder head. The exhaust manifolds
are covered by a three layer laminated heat shield
for thermal protection and noise reduction. The heat
shields are fastened with a torque prevailing nut
that is backed off slightly to allow for the thermal
expansion of the exhaust manifold.
OPERATION
The exhaust manifolds collect the engine exhaust
exiting the combustion chambers, then channels the
exhaust gases to the exhaust pipes attached to the
manifolds.
REMOVAL
EXHAUST MANIFOLD
(1) Disconnect negative battery cable.
(2) Raise vehicle.
(3) Remove exhaust pipe to manifold bolts.
(4) Lower vehicle.
(5) Install engine support fixture special tool
#8534.
(6) Raise engine enough to remove manifolds.
CAUTION: Do not damage engine harness while
raising the engine.
(7) Remove heat shield.
(8) Remove manifold bolts.
(9) Remove manifold and gasket.
CLEANING
Clean mating surfaces on cylinder head and mani-
fold. Wash with solvent and blow dry with com-
pressed air.
9 - 226 ENGINE - 5.7LDR
INTAKE MANIFOLD (Continued)

INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness
with a straight edge. Gasket surfaces must be flat
within 0.2 mm per 300 mm (0.008 inch per foot).
INSTALLATION
EXHAUST MANIFOLD
(1) Install manifold gasket and manifold.
(2) Install manifold bolts and tighten to 25 N´m
(18 ft. lbs.).
(3) Install heat shield and tighten nuts to 15 N´m
(11 ft. lbs.).
(4) Lower engine.
CAUTION: Do not damage engine harness while
lowering the engine.
(5) Remove engine support fixture from engine.
(6) Raise vehicle.
(7) Tighten right and left side engine mount
through bolts.
(8) Install exhaust flange to pipe bolts.
(9) Lower vehicle.
(10) Connect negative battery cable.
TIMING/CHAIN COVER
REMOVAL
(1) Disconnect the battery negative cable.
(2) Remove air cleaner assembly.
(3) Drain cooling system.
(4) Remove accessory drive belt.
(5) Remove fan and fan drive assembly (Refer to 7
- COOLING/ENGINE/FAN DRIVE VISCOUS
CLUTCH - REMOVAL).
(6) Remove coolant bottle and washer bottle.
(7) Remove fan shroud.
NOTE: It is not necessary to disconnect A/C lines or
discharge freon.
(8) Remove A/C compressor and set aside.
(9) Remove the generator.
(10) Remove upper radiator hose.
(11) Disconnect both heater hoses at timing cover.
(12) Disconnect lower radiator hose at engine.
(13) Remove accessory drive belt tensioner and
both idler pulleys.
(14) Remove crankshaft damper(Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).NOTE: Do not remove the hoses from the power
steering pump.
(15) Remove power steering pump and set aside.
(16) Remove the dipstick support bolt.
(17) Drain the engine oil.
(18) Remove the oil pan and pick up tube(Refer to
9 - ENGINE/LUBRICATION/OIL PAN - REMOVAL).
NOTE: It is not necessary to remove water pump for
timing cover removal.
(19) Remove timing cover bolts and remove cover.
INSTALLATION
(1) Clean timing chain cover and block surface.
NOTE: Always install a new gasket on timing cover.
(2) Install cover and new gasket. Tighten fasteners
to 28 N´m (250 in. lbs.).
NOTE: The large lifting stud is torqued to 55 N´m
(40 ft. lbs.).
(3) Install the oil pan and pick up tube(Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
(4) Install the A/C compressor.
(5) Install the generator.
(6) Install power steering pump.
(7) Install the dipstick support bolt.
(8) Install the thermostat housing.
(9) Install crankshaft damper(Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION).
(10) Install accessory drive belt tensioner assembly
and both idler pulleys.
(11) Install radiator lower hose.
(12) Install both heater hoses.
(13) Install radiator fan shroud.
(14) Install the fan and fan drive assembly
(15) Install the accessory drive belt.
(16) Install the coolant bottle and washer bottle.
(17) Install the upper radiator hose.
(18) Install the air cleaner assembly.
(19) Fill cooling system.
(20) Refill engine oil.
(21) Connect the battery negative cable.
DRENGINE - 5.7L 9 - 227
EXHAUST MANIFOLD (Continued)

LUBRICATION
DESCRIPTION
NOTE: Refer to (Fig. 105) and (Fig. 106) for circuit
illustrations.
A gear driven gerotor type oil pump is mounted
behind the front gear cover in the lower right portion
on the engine.
OPERATION
A gerotor style oil pump draws oil from the crank-
case through the suction tube and delivers it through
the block where it enters the oil cooler cover and
pressure regulator valve. When oil pressure exceeds
517 kPa (75 PSI), the valve opens exposing the dump
port, which routes excess oil back to the oil pump.
At the same time, oil is directed to a cast in pas-
sage in the oil cooler cover, leading to the oil cooler
element. As the oil travels through the element
plates, it is cooled by engine coolant traveling past
the outside of the plates. It is then routed to the oil
filter head and through a full flow oil filter. If a
plugged filter is encountered, the filter by-pass valve
opens, allowing unfiltered oil to lubricate the engine.
This condition can be avoided by frequent oil and fil-
ter changes, per the maintenance schedules found in
the owners manual. The by-pass valve is calibrated
to open when it sees a pressure drop of more than
345 kPa (50 psi) across the oil filter.
The oil filter head then divides the oil between the
engine and the turbocharger. The turbocharger
receives filtered, cooled and pressurized oil through a
supply line from the filter head. The oil lubricates
the turbocharger and returns to the pan by way of a
drain tube connecting the bottom of the turbocharger
to a pressed in tube in the cylinder block.
Oil is then carried across the block to an angle
drilling which intersects the main oil rifle. The main
oil rifle runs the length of the block and delivers oil
to the crankshaft main journals and valve train. Oil
travels to the crankshaft through a series of transfer
drillings (one for each main bearing) and lubricates a
groove in the main bearing upper shell. From there
another drilling feeds the camshaft main journals.The saddle jet piston cooling nozzles are also sup-
plied by the main bearing upper shell. J-jet piston
cooling nozzles are supplied by a separate oil rifle.
Plugs are used in place of saddle jets when J-jets are
used. J-jet hole locations are plugged when saddle jet
cooling nozzles are used. Crankshaft internal cross-
drillings supply oil to the connecting rod journals.
Another series of transfer drillings intersecting the
main oil rifle supply the valve train components. Oil
travels up the drilling, through a hole in the head
gasket, and through a drilling in the cylinder head
(one per cylinder), where it enters the rocker arm
pedestal and is divided between the intake and
exhaust rocker arm. Oil travels up and around the
rocker arm mounting bolt, and lubricates the rocker
shaft by cross drillings that intersect the mounting
bolt hole. Grooves at both ends of the rocker shaft
supply oil through the rocker arm where the oil trav-
els to the push rod and socket balls (Fig. 105) and
(Fig. 106).
DIAGNOSIS AND TESTINGÐENGINE OIL
PRESSURE
(1) Remove the 1/8 npt plug from the top of the oil
filter housing.
(2) Install Oil Pressure Line and Gauge Tool
C-3292 with a suitable adapter.
(3) Start engine and warm to operating tempera-
ture.
(4) Record engine oil pressure and compare with
engine oil pressure chart.
CAUTION: If engine oil pressure is zero at idle, DO
NOT RUN THE ENGINE.
Engine Oil Pressure (MIN)
At Idle 68.9 kPa (10 psi)
At 2500 rpm 206.9 kPa (30 psi)
If minimum engine oil pressure is below these
ranges, (Refer to 9 - ENGINE - DIAGNOSIS AND
TESTING).
(5) Remove oil pressure gauge and install the 1/8
npt plug.
DRENGINE 5.9L DIESEL 9 - 289