Downloaded from www.Manualslib.com manuals search engine (15) Remove intake manifold and throttle body as
an assembly. Discard the flange side gaskets and the
front and rear cross-over gaskets.
(16) Remove exhaust manifolds.
(17) Remove rocker arm assemblies and push rods.
Identify to ensure installation in original locations.
(18) Remove the head bolts from each cylinder
head and remove cylinder heads. Discard the cylin-
der head gasket.
(19) Remove spark plugs.
INSTALLATION
(1) Position the new cylinder head gaskets onto
the cylinder block.
(2) Position the cylinder heads onto head gaskets
and cylinder block.
(3) Starting at top center, tighten all cylinder head
bolts, in sequence, to 68 N´m (50 ft. lbs.) torque (Fig.
45). Repeat procedure, tighten all cylinder head bolts
to 143 N´m (105 ft. lbs.) torque. Repeat procedure to
confirm that all bolts are at 143 N´m (105 ft. lbs.)
torque.
CAUTION: When tightening the rocker arm bolts,
make sure the piston in that cylinder is NOT at
TDC. Contact between the valves and piston could
occur.
(4) Install push rods and rocker arm assemblies in
their original position. Tighten the bolts to 28 N´m
(21 ft. lbs.) torque.
(5) Install the intake manifold and throttle body
assembly.
(6) Install exhaust manifolds. Tighten the bolts
and nuts to 34 N´m (25 ft. lbs.) torque.
(7) Adjust spark plugs to specifications. Refer to
IGNITION SYSTEM. Install the plugs and tighten to
41 N´m (30 ft. lbs.) torque.
(8) Install coil wires.
(9) Connect heat indicator sending unit wire.(10) Connect the heater hoses and bypass hose.
(11) Install distributor cap and wires.
(12) Connect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(13) Install the fuel supply line.
(14) Install the generator and drive belt. Tighten
generator mounting bolt to 41 N´m (30 ft. lbs.)
torque.
(15) Install the intake manifold-to-generator
bracket support rod. Tighten the bolts.
(16) Place the cylinder head cover gaskets in posi-
tion and install cylinder head covers. Tighten the
bolts to 11 N´m (95 in. lbs.) torque.
(17) Install closed crankcase ventilation system.
(18) Connect the evaporation control system.
(19) Install the air cleaner assembly and air inlet
hose.
(20) Install the heat shields. Tighten the bolts to
41 N´m (30 ft. lbs.) torque.
(21) Fill cooling system.
(22) Connect the battery negative cable.
VALVES AND VALVE SPRINGS
REMOVAL
(1) Remove the cylinder head. Refer to Cylinder
Head in this section for correct procedure.
(2) Compress valve springs using Valve Spring
Compressor Tool MD- 998772A and adapter 6716A.
(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 MD-998772A and adapter 6716A,
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 ofFig. 45 Cylinder Head Bolt Tightening Sequence
9 - 108 5.2L ENGINEDN
REMOVAL AND INSTALLATION (Continued)
Downloaded from www.Manualslib.com manuals search engine REFACING VALVES AND VALVE SEATS
The intake and exhaust valves have a 43-1/4É to
43-3/4É face angle and a 44-1/4É to 44-3/4É seat angle
(Fig. 77).
VALVES
Inspect the remaining margin after the valves are
refaced (Fig. 78). Valves with less than 1.190 mm
(0.047 inch) margin should be discarded.VALVE SEATS
CAUTION: DO NOT un-shroud valves during valve
seat refacing (Fig. 79).
(1) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be
obtained.
Fig. 77 Valve Face and Seat Angles
1 ± CONTACT POINT
ITEM DESCRIPTION SPECIFICATION
ASEAT WIDTH - 1.016 - 1.524
mm
INTAKE (0.040 - 0.060
in.)
EXHAUST 1.524 - 2.032
mm
(0.060 - 0.080
in.)
BFACE ANGLE
(INT. AND
EXT.)43
1¤4É-433¤4É
CSEAT ANGLE
(INT. AND
EXT.)44
1¤4É-443¤4É
DCONTACT
SURFACE Ð
Fig. 78 Intake and Exhaust Valves
1 ± MARGIN
2 ± VALVE SPRING RETAINER LOCK GROOVE
3 ± STEM
4±FACE
Fig. 79 Refacing Valve Seats
1±STONE
2 ± PILOT
3 ± VALVE SEAT
4 ± SHROUD
9 - 122 5.2L ENGINEDN
DISASSEMBLY AND ASSEMBLY (Continued)
Downloaded from www.Manualslib.com manuals search engine (2) Measure the concentricity of valve seat using a
dial indicator. Total runout should not exceed 0.051
mm (0.002 inch) total indicator reading.
(3) Inspect the valve seat with Prussian blue to
determine where the valve contacts the seat. To do
this, coat valve seat LIGHTLY with Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to the top edge of valve face, lower valve seat
with a 15É stone. If the blue is transferred to bottom
edge of valve face raise valve seat with a 60É stone.
(4) When seat is properly positioned the width of
intake seats should be 1.016-1.524 mm (0.040-0.060
inch). The width of the exhaust seats should be
1.524-2.032 mm (0.060-0.080 inch).
VALVE SPRING INSPECTION
Whenever valves have been removed for inspection,
reconditioning or replacement, valve springs should
be tested. As an example the compression length of
the spring to be tested is 1-5/16 inch. Turn table of
Universals Valve Spring Tester Tool until surface is
in line with the 1-5/16 inch mark on the threaded
stud. Be sure the zero mark is to the front (Fig. 80).
Place spring over stud on the table and lift compress-
ing lever to set tone device. Pull on torque wrench
until ping is heard. Take reading on torque wrench
at this instant. Multiply this reading by 2. This will
give the spring load at test length. Fractional mea-
surements are indicated on the table for finer adjust-
ments. Refer to specifications to obtain specified
height and allowable tensions. Discard the springs
that do not meet specifications.
OIL PUMP
DISASSEMBLE
(1) Remove the relief valve as follows:
(a) Remove cotter pin. Drill a 3.175 mm (1/8
inch) hole into the relief valve retainer cap and
insert a self-threading sheet metal screw.
(b) Clamp screw into a vise and while support-
ing oil pump, remove cap by tapping pump body
using a soft hammer. Discard retainer cap and
remove spring and relief valve (Fig. 81).
(2) Remove oil pump cover (Fig. 82).
(3) Remove pump outer rotor and inner rotor with
shaft (Fig. 82).
(4) Wash all parts in a suitable solvent and inspect
carefully for damage or wear.
ASSEMBLE
(1) Install pump rotors and shaft, using new parts
as required.
(2) Position the oil pump cover onto the pump
body. Tighten cover bolts to 11 N´m (95 in. lbs.)
torque.
(3) Install the relief valve and spring. Insert the
cotter pin.
(4) Tap on a new retainer cap.
(5) Prime oil pump before installation by filling
rotor cavity with engine oil.
Fig. 80 Testing Valve Spring for Compressed
Length
1 ± TORQUE WRENCH
2 ± VALVE SPRING TESTER
Fig. 81 Oil Pressure Relief Valve
1 ± OIL PUMP ASSEMBLY
2 ± COTTER PIN
3 ± RELIEF VALVE
4 ± RETAINER CAP
5 ± SPRING
DN5.2L ENGINE 9 - 123
DISASSEMBLY AND ASSEMBLY (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 Use a 2 step procedure so the valve guides are
reamed true in relation to the valve seat:
²Step 1ÐReam to 0.0763 mm (0.003 inch).
²Step 2ÐReam to 0.381 mm (0.015 inch).
REFACING VALVES AND VALVE SEATS
The intake and exhaust valves have a 43-1/4É to
43-3/4É face angle and a 44-1/4É to 44-3/4É seat angle
(Fig. 20).
VALVES
Inspect the remaining margin after the valves are
refaced (Fig. 21). Valves with less than 1.190 mm
(0.047 inch) margin should be discarded.
VALVE SEATS
CAUTION: DO NOT un-shroud valves during valve
seat refacing (Fig. 22).
(1) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be
obtained.(2) Measure the concentricity of valve seat using a
dial indicator. Total runout should not exceed 0.051
mm (0.002 inch) total indicator reading.
(3) Inspect the valve seat with Prussian blue to
determine where the valve contacts the seat. To do
this, coat valve seatLIGHTLYwith Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to the top edge of valve face, lower valve seat
with a 15É stone. If the blue is transferred to bottom
edge of valve face raise valve seat with a 60É stone.
(4) When seat is properly positioned the width of
intake seats should be 1.016-1.524 mm (0.040-0.060
REAMER SIZES
REAMER O/S VALVE GUIDE SIZE
0.076 mm (0.003 in.) 8.026 - 8.052 mm
(0.316 - 0.317 in.)
0.381 mm (0.015 in.) 8.331 - 8.357 mm
(0.328 - 0.329 in.)
Fig. 20 Valve Face and Seat Angles
1 ± CONTACT POINT
VALVE FACE AND VALVE SEAT ANGLE CHART
ITEM DESCRIPTION SPECIFICATION
ASEAT WIDTH± 1.016 - 1.524 mm
INTAKE (0.040 - 0.060 in.)
SEAT WIDTH± 1.524 - 2.032 mm
EXHAUST (0.060 - 0.080 in.)
BFACE ANGLE
(INT. and EXT.) 43
1¤4É-433¤4É
CSEAT ANGLE
(INT. and EXT.) 44
1¤4É-443¤4É
DCONTACT
SURFACE Ð
Fig. 21 Intake and Exhaust Valves
1 ± MARGIN
2 ± VALVE SPRING RETAINER LOCK GROOVE
3 ± STEM
4±FACE
9 - 154 5.9L ENGINEDN
SERVICE PROCEDURES (Continued)
Downloaded from www.Manualslib.com manuals search engine inch). The width of the exhaust seats should be
1.524-2.032 mm (0.060-0.080 inch).
VALVE SPRING INSPECTION
Whenever valves have been removed for inspection,
reconditioning or replacement, valve springs should
be tested. As an example the compression length of
the spring to be tested is 1-5/16 inch. Turn table of
Universal Valve Spring Tester Tool until surface is in
line with the 1-5/16 inch mark on the threaded stud.
Be sure the zero mark is to the front (Fig. 23). Place
spring over stud on the table and lift compressing
lever to set tone device. Pull on torque wrench until
ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by 2. This will give the
spring load at test length. Fractional measurements
are indicated on the table for finer adjustments.
Refer to specifications to obtain specified height and
allowable tensions. Discard the springs that do not
meet specifications.
MEASURING TIMING CHAIN STRETCH
NOTE: To access timing chain Refer to Timing
Chain Cover in Removal and Installation Section.
(1) Place a scale next to the timing chain so that
any movement of the chain may be measured.
(2) Place a torque wrench and socket over cam-
shaft sprocket attaching bolt. Apply torque in the
direction of crankshaft rotation to take up slack; 41
N´m (30 ft. lbs.) torque with cylinder head installed
or 20 N´m (15 ft. lbs.) torque with cylinder head
removed. With a torque applied to the camshaftsprocket bolt, crankshaft should not be permitted to
move. It may be necessary to block the crankshaft to
prevent rotation.
(3) Hold a scale with dimensional reading even
with the edge of a chain link. With cylinder heads
installed, apply 14 N´m (30 ft. lbs.) torque in the
reverse direction. With the cylinder heads removed,
apply 20 N´m (15 ft. lbs.) torque in the reverse direc-
tion. Note the amount of chain movement (Fig. 24).
(4) Install a new timing chain, if its movement
exceeds 3.175 mm (1/8 inch).
(5) If chain is not satisfactory, remove camshaft
sprocket attaching bolt and remove timing chain with
crankshaft and camshaft sprockets.
(6) 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. 22 Refacing Valve Seats
1±STONE
2 ± PILOT
3 ± VALVE SEAT
4 ± SHROUD
Fig. 23 Testing Valve Spring for Compressed
Length
1 ± TORQUE WRENCH
2 ± VALVE SPRING TESTER
Fig. 24 Measuring Timing Chain Wear and Stretch
1 ± TORQUE WRENCH
2 ± 3.175 MM
(0.125 IN.)
DN5.9L ENGINE 9 - 155
SERVICE PROCEDURES (Continued)
Downloaded from www.Manualslib.com manuals search engine (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) Coat valve stems with lubrication oil and insert
them in cylinder head.
(2) If valves or seats are reground, check valve
stem height. If valve is too long, replace cylinder
head.
(3) Install new seals on all valve guides. Install
valve springs and valve retainers.
(4) Compress valve springs with Valve Spring
Compressor Tool MD-998772A, install locks and
release tool. If valves and/or seats are ground, mea-
sure 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. If spacers are installed, measure from the
top of spacer. If height is greater than 42.86 mm
(1-11/16 inches), install a 1.587 mm (1/16 inch)
spacer in head counterbore. This should bring spring
height back to normal 41.27 to 42.86 mm (1-5/8 to
1-11/16 inch).
HYDRAULIC TAPPETS
REMOVAL
(1) Remove the air cleaner assembly and air inlet
hose.
(2) Remove cylinder head cover, rocker assembly
and push rods. Identify push rods to ensure installa-
tion in original location.
(3) Remove intake manifold, yoke retainer and
aligning yokes.
(4) Slide Hydraulic Tappet Remover/Installer Tool
C-4129-A through opening in cylinder head and seat
tool firmly in the head of tappet.
(5) Pull tappet out of bore with a twisting motion.
If all tappets are to be removed, identify tappets to
ensure installation in original location.
INSTALLATION
(1) If the tappet or bore in cylinder block is scored,
scuffed, or shows signs of sticking, ream the bore to
next oversize. Replace with oversize tappet.
(2) Lubricate tappets.
(3) Install tappets and push rods in their original
positions. Ensure that the oil feed hole in the side of
the tappet body faces up (away from the crankshaft).
(4) Install aligning yokes with ARROW toward
camshaft.
(5) Install yoke retainer. Tighten the bolts to 23
N´m (200 in. lbs.) torque. Install intake manifold.
(6) Install push rods in original positions.(7) Install rocker arm.
(8) Install cylinder head cover.
(9) Install air cleaner assembly and air inlet hose.
(10) Start and operate engine. Warm up to normal
operating temperature.
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.
VIBRATION DAMPER
REMOVAL
(1) Disconnect the battery negative cable.
(2) Remove the cooling system fan.
(3) Remove the cooling fan shroud.
(4) Remove the accessory drive belt. Refer to
COOLING SYSTEM.
(5) Remove vibration damper bolt and washer from
end of crankshaft.
(6) Position Special Tool 8513 Insert into the
crankshaft nose.
(7) Install Special Tool 1026 Three Jaw Puller onto
the vibration damper (Fig. 51).
(8) Pull vibration damper off of the crankshaft.
INSTALLATION
CAUTION: Thoroughly remove any contaminants
from the crankshaft nose and the vibration damper
bore. Failure to do so can cause sever damage to
the crankshaft.
(1) Position the vibration damper onto the crank-
shaft.
Fig. 51 Vibration Damper Removal
1 ± SPECIAL TOOL 8513 INSERT
2 ± SPECIAL TOOL 1026
9 - 168 5.9L ENGINEDN
REMOVAL AND INSTALLATION (Continued)