Downloaded from www.Manualslib.com manuals search engine CYLINDER BLOCK
DISASSEMBLE
With Engine removed from vehicle:
(1) Remove the cylinder heads. refer to Cylinder
Head in this section for correct procedure.
(2) Remove the exhaust manifolds. Refer to
Exhaust Manifolds in this section.
(3) Remove the oil pan. Refer to Oil Pan in this
section.
(4) Remove the piston and connecting rod assem-
blies. Refer to Piston and Connecting Rod in this sec-
tion.
(5) Remove the crankshaft. Refer to Crankshaft in
this section.
(6) Remove the core plugs.
ASSEMBLE
(1) Install the core plugs.
(2) Install the crankshaft.
(3) Install the piston and connecting rods.
(4) Install the oil pan.
(5) Install the cylinder heads.
(6) Install the exhaust manifolds.
(7) Install the intake manifold.
(8) Install the engine into the vehicle.
CLEANING AND INSPECTION
CYLINDER HEAD COVER
CLEANING
Clean cylinder head cover gasket surface.
Clean head rail, if necessary.
INSPECTION
Inspect cover for distortion and straighten, if nec-
essary.
Check the gasket for use in head cover installation.
If damaged, use a new gasket.
CYLINDER HEAD ASSEMBLY
CLEANING
Clean all surfaces of cylinder block and cylinder
heads.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
INSPECTION
Inspect all surfaces with a straightedge if there is
any reason to suspect leakage. If out-of-flatness
exceeds 0.00075 mm/mm (0.00075 inch/inch) times
the span length in inches in any direction, either
replace head or lightly machine the head surface.
FOR EXAMPLE:A 305 mm (12 inch) span is
0.102 mm (0.004 inch) out-of-flat. The allowable out-
of-flat is 305 X 0.00075 (12 X 0.00075) equals 0.23
mm (0.009 inch). This amount of out-of-flat is accept-
able.
The cylinder head surface finish should be
1.78-3.00 microns (70-125 microinches).
PISTON AND CONNECTING ROD ASSEMBLY
INSPECTION
Check the crankshaft connecting rod journal for
excessive wear, taper and scoring.
Check the cylinder block bore for out-of-round,
taper, scoring and scuffing.
Check the pistons for taper and elliptical shape
before they are fitted into the cylinder bore (Fig. 83).
OIL PAN
CLEANING
Clean the block and pan gasket surfaces.
Trim or remove excess sealant film in the rear
main cap oil pan gasket groove.DO NOT remove
the sealant inside the rear main cap slots.
If present, trim excess sealant from inside the
engine.
Fig. 82 Oil Pump
1 ± INNER ROTOR AND SHAFT
2 ± BODY
3 ± DISTRIBUTOR DRIVESHAFT (REFERENCE)
4 ± COTTER PIN
5 ± RETAINER CAP
6 ± SPRING
7 ± RELIEF VALVE
8 ± LARGE CHAMFERED EDGE
9 ± BOLT
10 ± COVER
11 ± OUTER ROTOR
9 - 124 5.2L ENGINEDN
DISASSEMBLY AND ASSEMBLY (Continued)
Downloaded from www.Manualslib.com manuals search engine Clean oil pan in solvent and wipe dry with a clean
cloth.
Clean oil screen and pipe thoroughly in clean sol-
vent. Inspect condition of screen.
INSPECTION
Inspect oil drain plug and plug hole for stripped or
damaged threads. Repair as necessary.
Inspect oil pan mounting flange for bends or distor-
tion. Straighten flange, if necessary.
OIL PUMP
INSPECTION
Mating surface of the oil pump cover should be
smooth. Replace pump assembly if cover is scratched
or grooved.
Lay a straightedge across the pump cover surface
(Fig. 84). If a 0.038 mm (0.0015 inch) feeler gauge
can be inserted between cover and straightedge,
pump assembly should be replaced.
Measure thickness and diameter of OUTER rotor.
If outer rotor thickness measures 20.9 mm (0.825
inch) or less or if the diameter is 62.7 mm (2.469
inches) or less, replace outer rotor (Fig. 85).
If inner rotor measures 20.9 mm (0.825 inch) or
less, replace inner rotor and shaft assembly (Fig. 86).
Slide outer rotor into pump body. Press rotor to the
side with your fingers and measure clearance
between rotor and pump body (Fig. 87). If clearance
is 0.356 mm (0.014 inch) or more, replace oil pump
assembly.
Install inner rotor and shaft into pump body. If
clearance between inner and outer rotors is 0.203
mm (0.008 inch) or more, replace shaft and both
rotors (Fig. 88).
Fig. 83 Piston Measurements
1 ± 49.53 mm
(1.95 IN.)
PISTON MEASUREMENT CHART
PISTON A DIA = PISTON BORE
SIZE DIAMETER DIAMETER
MIN. MAX. MIN. MAX.
mm
(in.)mm
(in.)mm
(in.)mm (in.)
AÐÐÐ Ð
B101.580 101.592 101.605 101.618
(3.9992) (3.9997) (4.0002) (4.0007)
C101.592 101.605 101.618 101.630
(3.9997) (4.0002) (4.0007) (4.0012)
D101.605 101.618 101.630 101.643
(4.0002) (4.0007) (4.0012) (4.0017)
EÐÐÐ Ð
DESCRIPTION SPECIFICATION
PISTON PIN 25.007 - 25.015 mm
BORE (.9845 -.9848 in.)
RING GROOVE
HEIGHT
OIL RAIL 4.033 - 4.058 mm
(.1588 -.1598 in.)
COMPRESSION
RAIL1.529 - 1.554 mm
(.0602 -.0612 in.)
TOTAL FINISHED 470.862 grams
WEIGHT (16.6076.0706 ounces)
Fig. 84 Checking Oil Pump Cover Flatness
1 ± COVER
2 ± STRAIGHT EDGE
3 ± FEELER GAUGE
DN5.2L ENGINE 9 - 125
CLEANING AND INSPECTION (Continued)
Downloaded from www.Manualslib.com manuals search engine If oil pressure was low and pump is within specifi-
cations, inspect for worn engine bearings or other
reasons for oil pressure loss.
CYLINDER BLOCK
CLEANING
Clean cylinder block thoroughly and check all core
hole plugs for evidence of leaking.
INSPECTION
Examine block for cracks or fractures.
The cylinder walls should be checked for out-of-
round and taper with Cylinder Bore Indicator Tool
C-119. The cylinder block should be bored and honed
with new pistons and rings fitted if:
²The cylinder bores show more than 0.127 mm
(0.005 inch) out-of-round.²The cylinder bores show a taper of more than
0.254 mm (0.010 inch).
²The cylinder walls are badly scuffed or scored.
Boring and honing operation should be closely coor-
dinated with the fitting of pistons and rings so spec-
ified clearances may be maintained.
Refer to Standard Service Procedures in the begin-
ning of this Group for the proper honing of cylinder
bores.
INTAKE MANIFOLD
CLEANING
Clean manifold in solvent and blow dry with com-
pressed air.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
The plenum pan rail must be clean and dry (free of
all foreign material).
INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness
with a straightedge.
EXHAUST MANIFOLD
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 sur-
faces of manifold for flatness with a straight edge.
Seal surfaces must be flat within 0.1 mm (0.004 inch)
overall.
Fig. 90 Proper Installation of Retainer Cap
1 ± RETAINER CAP
2 ± CHAMFER
3 ± COTTER KEY
DN5.2L ENGINE 9 - 127
CLEANING AND INSPECTION (Continued)
Downloaded from www.Manualslib.com manuals search engine SERVICE DIAGNOSISÐGASOLINE ENGINES
PERFORMANCE DIAGNOSIS CHARTÐGASOLINE ENGINES
CONDITION POSSIBLE CAUSES CORRECTION
ENGINE WILL
NOT CRANK1. Weak or dead battery 1. Charge/Replace Battery. Refer to Group 8A,
Battery, for correct procedures. Check charging
system. Refer to Group 8C, Charging Systems, for
correct procedures.
2. Corroded or loose battery
connections2. Clean/tighten suspect battery/starter connections
3. Faulty starter or related circuit(s) 3. Check starting system. Refer to Group 8B,
Starting Systems, for correct diagnostics/procedures
4. Seized accessory drive
component4. 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 Group 9, Engine, for correct diagnostics/
procedures
ENGINE CRANKS
BUT WILL NOT
START1. No spark 1. Check for spark. Refer to Group 8D, Ignition
System, for correct procedures.
2. No fuel 2. Perform fuel pressure test, and if necessary,
inspect fuel injector(s) and driver circuits. Refer to
Group 14, Fuel System, for correct procedures.
3. Low or no engine compression 3. Perform cylinder compression pressure test. Refer
to Group 9, Engine, for correct procedures.
ENGINE LOSS OF
POWER1. Worn or burned distributor rotor 1. Install new distributor rotor
2. Worn distributor shaft 2. Remove and repair distributor (Refer to Group 8D,
Ignition System
3. Worn or incorrect gapped spark
plugs3. Clean plugs and set gap. (Refer to Group 8D,
Ignition System)
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
9. Burned, warped, or pitted valves 9. Install/Reface valves as necessary
10. Plugged or restricted exhaust
system10. Install new parts as necessary
11. Faulty ignition cables 11. Replace any cracked or shorted cables
12. Faulty ignition coil 12. Test and replace, as necessary (Refer to Group
8D, Ignition System)
ENGINE STALLS
OR ROUGH IDLE1. Carbon build-up on throttle plate 1. Remove throttle body and de-carbon. (Refer to
Group 14 for correct procedures)
2. Engine idle speed too low 2. Check Idle Air Control circuit. (Refer to Group 14,
Fuel System)
9 - 142 5.9L ENGINEDN
DIAGNOSIS AND TESTING (Continued)
Downloaded from www.Manualslib.com manuals search engine CONDITION POSSIBLE CAUSES CORRECTION
3. Worn or incorrectly gapped spark
plugs3. Replace or clean and re-gap spark plugs (Refer to
group 8D, Ignition System)
4. Worn or burned distributor rotor 4. Install new distributor rotor
5. Spark plug cables defective or
crossed5. Check for correct firing order or replace spark plug
cables. (Refer to Group 8D, Ignition System for
correct procedures.)
6. Faulty coil 6. Test and replace, if necessary (Refer to group 8D,
Ignition System)
7. Intake manifold vacuum leak 7. Inspect intake manifold gasket and vacuum hoses.
Replace if necessary
8. EGR valve leaking or stuck open 8. Test and replace, if necessary (Refer to group 25,
Emission Control Systems)
ENGINE MISSES
ON
ACCELERATION1. Worn or incorrectly gapped spark
plugs1. Replace spark plugs or clean and set gap. (Refer
to group 8D, Ignition System)
2. Spark plug cables defective or
crossed2. Replace or rewire secondary ignition cables. Refer
to Group 8D, Ignition System
3. Dirt in fuel system 3. Clean fuel system
4. Burned, warped or pitted valves 4. Install new valves
5. Faulty coil 5. Test and replace as necessary (refer to group 8D,
Ignition System)
MECHANICAL DIAGNOSIS CHARTÐGASOLINE ENGINES
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES/
LIFTERS1. High or low oil level
in crankcase1. Check for correct oil level. Adjust oil level by draining or adding
as needed
2. Thin or diluted oil 2. Change oil (Refer to Engine Oil Service in this group)
3. Low oil pressure 3. Check engine oil level. If ok, Perform oil pressure test. Refer to
this group for engine oil pressure test/specifications
4. Dirt in tappets/lash
adjusters4. 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
adjusters7. 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
DN5.9L ENGINE 9 - 143
DIAGNOSIS AND TESTING (Continued)
Downloaded from www.Manualslib.com manuals search engine CONDITION POSSIBLE CAUSES CORRECTION
CONNECTING
ROD NOISE1. Insufficient oil supply 1. Check engine oil level. (Refer to group 0, Lubrication and
Maintenance)
2. Low oil pressure 2. Check engine oil level. If ok, Perform oil pressure test. Refer to
this group for engine oil pressure test/specifications
3. Thin or diluted oil 3. Change oil to correct viscosity. Refer to this group for correct
procedure/engine oil specifications
4. Excessive connecting
rod bearing clearanceMeasure 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 rods6. Replace bent connecting rods
MAIN BEARING
NOISE1. Insufficient oil supply 1. Check engine oil level. (Refer to group 0, Lubrication and
Maintenance)
2. Low oil pressure 2. Check engine oil level. If ok, Perform oil pressure test. Refer to
this group for engine oil pressure test/specifications
3. Thin or diluted oil 3. Change oil to correct viscosity. Refer to this group for correct
procedure/engine oil specifications
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
PRESSURE1. Low oil level 1. Check oil level and fill if necessary
2. Faulty oil pressure
sending unit2. Install new sending unit
3. Clogged oil filter 3. Install new oil filter
4. Worn oil pump 4. Replace worn gears or oil pump assy
5. Thin or diluted oil 5. Change oil to correct viscosity. Refer to this group for correct
procedure/engine oil specifications
6. Excessive bearing
clearance6. Measure bearings for correct clearance
7. Oil pump relief valve
stuck7. Remove valve to inspect, clean and reinstall
8. Oil pump suction
tube loose, broken, bent
or clogged8. Inspect suction tube and clean or replace if necessary
9. Oil pump cover
warped or cracked9. Install new oil pump
9 - 144 5.9L ENGINEDN
DIAGNOSIS AND TESTING (Continued)
Downloaded from www.Manualslib.com manuals search engine CONDITION POSSIBLE CAUSES CORRECTION
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
5. Leaking intake 5. Replace gaskets
manifold cross-over
gaskets
EXCESSIVE OIL
CONSUMPTION
OR SPARK
PLUGS OIL
FOULED1. PCV System
malfunction1. Refer to group 25, Emission Control System for correct
operation
2. Intake manifold 2. Replace plenum
plenum pan gasket pan gasket
failure
3. Defective valve 3. Replace seals
stem seal(s)
4. Worn or broken
piston rings4. Hone cylinder bores. Install new rings
5. Scuffed pistons/
cylinder walls5. Hone cylinder bores and replace pistons as required
6. Carbon in oil control
ring groove6. Remove rings and de-carbon piston
7. Worn valve guides 6. Repair as
necessary
8. Piston rings fitted 8. Remove rings and
too tightly in grooves check ring end gap
and side clearance.
Replace if necessary
INTAKE MANIFOLD LEAKAGE DIAGNOSIS
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 RPMs, the area of the suspected
leak has been found.
(4) Repair as required.
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
DN5.9L ENGINE 9 - 145
DIAGNOSIS AND TESTING (Continued)
Downloaded from www.Manualslib.com manuals search engine 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.
(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 Engine Specifications for the correct
engine compression pressures.
CYLINDER HEAD GASKET FAILURE DIAGNOSIS
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
²Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
²Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test in this
section. An engine cylinder head gasket leaking
between adjacent cylinders will result in approxi-
mately a 50±70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
CYLINDER COMBUSTION PRESSURE LEAKAGE
TEST
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
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.
9 - 146 5.9L ENGINEDN
DIAGNOSIS AND TESTING (Continued)