
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.
Air Leak Detection Test Method
(1) Remove the PCV valve from the IAFM. Cap or
plug the PCV valve grommet.
(2) Attach an air hose with pressure gauge and
regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kPa (3 PSI) of test pressure.
(3) Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provide the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
(4) If the leakage occurs at the rear oil seal area,
refer to the section, Inspection for Rear Seal Area
Leak.
(5) If no leaks are detected, turn off the air supply
and remove the air hose and all plugs and caps.
Install the PCV valve.
(6) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak:
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, distributor seal,
camshaft bore cup plugs oil galley pipe plugs, oil
filter runoff, and main bearing cap to cylinder
block mating surfaces.
(4) If no leaks are detected, pressurize the crank-
case as outlined in the, Inspection (Engine oil Leaks
in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible the
crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
OIL
STANDARD PROCEDURE - ENGINE OIL
SERVICE
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY.
DRENGINE - 5.7L 9 - 215
LUBRICATION (Continued)

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. 27) 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.
OIL PAN
REMOVAL
(1) Disconnect the negative battery cable.
(2) Install engine support fixture special tool #
8534.Do not raise engine at this time.
(3) Loosen both left and right side engine mount
through bolts. Do not remove bolts.
(4) Remove the structural dust cover, if equipped.
(5) Drain engine oil.
(6) Remove the front crossmember(Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - REMOVAL).CAUTION: Only raise the engine enough to provide
clearance for oil pan removal. Check for proper
clearance at fan shroud to fan and cowl to intake
manifold.
(7) Raise engine using special tool # 8534 to pro-
vide clearance to remove oil pan.
NOTE: Do not pry on oil pan or oil pan gasket. Gas-
ket is integral to engine windage tray and does not
come out with oil pan.
(8) Remove the oil pan mounting bolts and oil pan.
NOTE: The double ended oil pan studs must be
installed in the same location that they were
removed from.
(9) Unbolt oil pump pickup tube and remove tube.
(10) Inspect the integral windage tray and gasket
and replace as needed.
INSTALLATION
(1) Clean the oil pan gasket mating surface of the
block and oil pan.
(2) Inspect the integral windage tray and gasket
and replace as needed.
(3) Reinstall the oil pump pickup tube with new
o-ring. Tighten tube to pump fasteners to 28 N´m
(250 in. lbs.).
NOTE: The double ended oil pan studs must be
installed in the same location that they were
removed from.
(4) Position the oil pan and install the mounting
bolts and studs.. Tighten the mounting bolts to 12
N´m (105 in.lbs.).
(5) Lower the engine into mounts using special
tool # 8534.
(6) Install both the left and right side engine
mount through bolts. Tighten the nuts to 68 N´m (50
ft. lbs.).
(7) Remove special tool # 8534.
(8) Install structural dust cover, if equipped.
(9) Install the front crossmember(Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - INSTALLATION).
(10) Fill engine oil.
(11) Reconnect the negative battery cable.
(12) Start engine and check for leaks.
Fig. 27 Oil Filter Sealing Surface - Typical
1 - SEALING SURFACE
2 - RUBBER GASKET
3 - OIL FILTER
DRENGINE - 5.7L 9 - 217
OIL FILTER (Continued)

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.
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
Fig. 30 Measuring Clearance Over Rotors - Typical
1 - STRAIGHT EDGE
2 - FEELER GAUGE
DRENGINE - 5.7L 9 - 219
OIL PUMP (Continued)

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) Sensor
²Throttle 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.
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.
9 - 220 ENGINE - 5.7LDR
INTAKE MANIFOLD (Continued)

(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.
TIMING/CHAIN AND
SPROCKETS
REMOVAL
(1) Disconnect battery negative cable.
(2) Drain cooling system.
(3) Remove Timing Chain Cover.
CAUTION: The camshaft pin and the slot in the cam
sprocket must be clocked at 12:00. The crankshaft
keyway must be clocked at 2:00. The crankshaft
sprocket must be installed so that the dots and or
paint marking is at 6:00.
(4) Re-install the vibration damper bolt finger
tight. Using a suitable socket and breaker bar, rotate
the crankshaft to align timing chain sprockets and
keyways as shown (Fig. 31).
(5) Retract tensioner shoe until hole in shoe lines
up with hole in bracket. Slide a suitable pin into the
holes.
(6) Remove camshaft sprocket attaching bolt and
remove timing chain with crankshaft and camshaft
sprockets.
(7) If tensioner assembly is to be replaced, remove
the tensioner to block bolts and remove tensioner
assembly.
Fig. 31 5.7L TIMING MARK ALIGNMENT
1 - Chain Tensioner
2 - Camshaft Sprocket
3 - Crankshaft Sprocket
DRENGINE - 5.7L 9 - 221
TIMING/CHAIN COVER (Continued)

INSTALLATION
(1) If tensioner assembly is being replaced, install
tensioner and mounting bolts. Torque bolts to 28 N´m
(250 in. lbs.).
(2) Retract tensioner if required.
CAUTION: The camshaft pin and the slot in the cam
sprocket must be clocked at 12:00. The crankshaft
keyway must be clocked at 2:00. The crankshaft
sprocket must be installed so that the dots and or
paint marking is at 6:00.
(3) Place both camshaft sprocket and crankshaft
sprocket on the bench with timing marks on exact
imaginary center line through both camshaft and
crankshaft bores (Fig. 32).
CAUTION: The timing chain must be installed with
the single plated link aligned with the dot and or
paint marking on the camshaft sprocket. The crank-
shaft sprocket is aligned with the dot and or paint
marking on the sprocket between two plated timing
chain links.
(4) Place timing chain around both sprockets (Fig.
32).
(5) Lift sprockets and chain (keep sprockets tight
against the chain in position as shown).(6) Slide both sprockets evenly over their respec-
tive shafts and check alignment of timing marks.
(7) Install the camshaft bolt. Tighten the bolt to
122 N´m (90 ft. lbs.) torque.
(8)Remove tensioner pin.Again, verify align-
ment of timing marks.
(9) Install the oil pump(Refer to 9 - ENGINE/LU-
BRICATION/OIL PUMP - INSTALLATION).
(10) Install the oil pan and pick up(Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
(11) Install the timing chain cover(Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(12) Fill cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(13) Connect battery negative cable.
(14) Start engine and check for oil and coolant
leaks.
TIMING CHAIN/TENSIONER
DESCRIPTION
The timing chain tensioner is a stamped steel con-
stant tension mechanical design. It is mounted to the
front of the engine, behind the timing chain drive.
OPERATION
The timing chain tension is maintained by routing
the timing chain through the tensioner assembly. A
nylon covered spring steel arm presses on the timing
chain maintaining the correct chain tension.
Fig. 32 5.7L TIMING MARK ALIGNMENT
1 - Chain Tensioner
2 - Camshaft Sprocket
3 - Crankshaft Sprocket
9 - 222 ENGINE - 5.7LDR
TIMING/CHAIN AND SPROCKETS (Continued)

DIAGNOSIS AND TESTINGÐENGINE DIAGNOSIS - PERFORMANCE
PERFORMANCE DIAGNOSIS CHARTÐGASOLINE ENGINES
CONDITION POSSIBLE CAUSES CORRECTION
ENGINE WILL NOT CRANK 1. Weak or dead battery 1. Charge/Replace Battery. (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM/
BATTERY - STANDARD PROCEDURE).
Check charging system. (Refer to 8 -
ELECTRICAL/CHARGING - DIAGNOSIS
AND TESTING).
2. Corroded or loose battery connections 2. Clean/tighten suspect battery/starter
connections
3. Faulty starter or related circuit(s) 3. Check starting system. (Refer to 8 -
ELECTRICAL/STARTING - DIAGNOSIS
AND TESTING)
4. Seized accessory drive component 4. Remove accessory drive belt and
attempt to start engine. If engine starts,
repair/replace seized component.
5. Engine internal mechanical failure or
hydro-static lock5. Refer to (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
ENGINE CRANKS BUT
WILL NOT START1. No spark 1. Check for spark. (Refer to 8 -
ELECTRICAL/IGNITION CONTROL -
DESCRIPTION)
2. No fuel 2. Perform fuel pressure test, and if
necessary, inspect fuel injector(s) and
driver circuits. (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY/FUEL PUMP -
DIAGNOSIS AND TESTING).
3. Low or no engine compression 3. Perform cylinder compression pressure
test. (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING).
ENGINE LOSS OF POWER 1. Worn or burned distributor rotor 1. Install new distributor rotor
2. Worn distributor shaft 2. Remove and repair distributor (Refer to
8 - ELECTRICAL/IGNITION CONTROL/
DISTRIBUTOR - REMOVAL).
3. Worn or incorrect gapped spark plugs 3. Clean plugs and set gap. (Refer to 8 -
ELECTRICAL/IGNITION CONTROL/
SPARK PLUG - CLEANING).
4. Dirt or water in fuel system 4. Clean system and replace fuel filter
5. Faulty fuel pump 5. Install new fuel pump
6. Incorrect valve timing 6. Correct valve timing
7. Blown cylinder head gasket 7. Install new cylinder head gasket
8. Low compression 8. Test cylinder compression (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).
9. Burned, warped, or pitted valves 9. Install/Reface valves as necessary
10. Plugged or restricted exhaust system 10. Install new parts as necessary
11. Faulty ignition cables 11. Replace any cracked or shorted cables
9 - 226 ENGINE - 5.9LDR
ENGINE - 5.9L (Continued)

DIAGNOSIS AND TESTINGÐCYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise, the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs (Refer to 8 - ELEC-
TRICAL/IGNITION CONTROL/SPARK PLUG -
REMOVAL).
(3) Secure the throttle in the wide-open position.
(4) Disconnect the ignition coil.
(5) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(6) Record the compression pressure on the third
revolution. Continue the test for the remaining cylin-
ders.
(Refer to 9 - ENGINE - SPECIFICATIONS) for the
correct engine compression pressures.
DIAGNOSIS AND TESTING - 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
jacket²Any causes for combustion/compression pressure
loss
WARNING: DO NOT REMOVE THE RADIATOR CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM HOT COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the radiator cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn OFF the
engine.
Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner.
Calibrate the tester according to the manufactur-
er's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.
Perform the test procedure on each cylinder accord-
ing to the tester manufacturer's instructions. While
testing, listen for pressurized air escaping through
the throttle body, tailpipe or oil filler cap opening.
Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder CYLINDER COMBUSTION
PRESSURE LEAKAGE DIAGNOSIS CHART.
CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
AIR ESCAPES THROUGH
THROTTLE BODYIntake valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary
AIR ESCAPES THROUGH
TAILPIPEExhaust valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary
AIR ESCAPES THROUGH
RADIATORHead gasket leaking or cracked
cylinder head or blockRemove cylinder head and inspect.
Replace defective part
MORE THAN 50% LEAKAGE
FROM ADJACENT CYLINDERSHead gasket leaking or crack in
cylinder head or block between
adjacent cylindersRemove cylinder head and inspect.
Replace gasket, head, or block as
necessary
MORE THAN 25% LEAKAGE AND
AIR ESCAPES THROUGH OIL
FILLER CAP OPENING ONLYStuck or broken piston rings;
cracked piston; worn rings and/or
cylinder wallInspect for broken rings or piston.
Measure ring gap and cylinder
diameter, taper and out-of-round.
Replace defective part as necessary
DRENGINE - 5.9L 9 - 231
ENGINE - 5.9L (Continued)