check engine light MITSUBISHI DIAMANTE 1900 Owner's Manual

3-38 ENGINEANDENGINEOVERHAUL
1.61&? 2.OL (Non-Turbo) DOHC Engines
g See Figure 158
*The 1.6L engine is not equipped with
silent shafts. Disregard all instructions per-
taining to silent shafts if working on that en-
gine.
1. Disconnect the negative battery cable.
2. Remove the engine undercover.
3. If necessary, remove the coolant reservoir.
4. Using the proper equipment, slightly raise
the engine to take the weight off the side engine
mount. Remove the engine mount bracket.
5. Remove the drive belts, tension pulley brack-
ets, water pump pulley and crankshaft pulley.
6. Remove all attaching screws and remove the
upper and lower timing belt covers.
7. Rotate the crankshaft clockwise and align the
timing marks so No. 1 piston will be at TDC of the
compression stroke. At this time the timing marks on
the camshaft sprocket and the upper surface of the
cylinder head should coincide, and the dowel pin of
the camshaft sprocket should be at the upper side.
*Always rotate the crankshaft in a clockwise
direction. Make a mark on the back of the
timing belt indicating the direction of rotation
so it may be reassembled in the same direc-
tion if it is to be reused.
8. Remove the auto tensioner and remove the
outermost timing belt.
9. Remove the timing belt tensioner pulley, ten-
sioner arm, idler pulley, oil pump sprocket, special
washer, flange and spacer.
10. Remove the silent shaft (inner) belt tensioner
and remove the belt.
To install: 11. Align the timing marks on the crankshaft
sprocket and the silent shaft sprocket. Fit the inner
timing belt over the crankshaft and silent shaft
sprocket. Ensure that there is no slack in the belt.
12. While holding the inner timing belt tensioner
with your fingers, adjust the timing belt tension by
applying a force towards the center of the belt, until
the tension side of the belt is taut. Tighten the ten-
sioner bolt.
*When tightening the bolt of the tensioner,
ensure that the tensioner pulley shaft does
not rotate with the bolt. Allowing it to rotate
with the bolt can cause excessive tension on
the belt.
13. Check belt for proper tension by depressing
the belt on it’s long side with your finger and noting
the belt deflection. The desired reading is 0.20-0.28
in. (5-7mm). If tension is not correct, readjust and
check belt deflection.
14. Install the flange, crankshaft and washer to
the crankshaft. The flange on the crankshaft sprocket
must be installed towards the inner trming belt
sprocket. Tighten bolt to 80-94 ft. Ibs. (110-130
Nm).
15. To install the oil pump sprocket, insert a
Phillips screwdriver with a shaft 0.31 in. (8mm) in di-
ameter into the plug hole in the left side of the cylin-
der block to hold the left silent shaft. Tighten the nut
to 36-43 ft. Ibs. (50-60 Nm).
16. Using a wrench, hold the camshaft at it’s
hexagon between journal No. 2 and 3, then tighten
the bolt to 58-72 ft. Ibs. (80-100 Nm). If no hexagon
is present between journal No. 2 and 3, hold the
sprocket stationary with a spanner wrench while
tightening the retainer bolt.
17. Carefully push the auto tensioner rod in until
the set hole in the rod aligns with the hole in the
cylinder. Place a wire into the hole to retain the rod.
18. Install the tensioner pulley onto the tensioner
arm. Locate the pinhole in the tensioner pulley shaft
to the left of the center bolt. Then, tighten the center
bolt finger-tight.
19. When installing the timing belt, turn the 2
camshaft sprockets so their dowel pins are located on
top. Align the timing marks facing each other with the
top surface of the cylinder head. When you let go of
the exhaust camshaft sprocket, it will rotate 1 tooth in
the counterclockwise direction. This should be taken
into account when installing the timing belts on the
sprocket.
*Both camshaft sprockets are used for the
intake and exhaust camshafts and are pro-
vided with 2 timing marks. When the
sprocket is mounted on the exhaust
camshaft, use the timing mark on the right
with the dowel pin hole on top. For the intake
camshafl sprocket, use the 1 on the left with
the dowel pin hole on top.
20. Align the crankshaft sprocket and oil pump
sprocket timing marks.
21. After alignment of the oil pump sprocket tim-
ing marks, remove the plug on the cylinder block and
insert a Phillips screwdriver with a shaft diameter of
0.31 in. (8mm) through the hole. If the shaft can be
inserted 2.4 in. deep, the silent shaft is in the correct
position. If the shaft of the tool can only be inserted
0.61 .O in. (2C-25mm) deep, turn the oil pump
sprocket 1 turn and realign the marks. Reinsert the
tool making sure it is inserted 2.4 in. deep. Keep the
tool inserted in hole for the remainder of this proce-
dure.
*The above step assures that the oil pump
socket is in correct orientation to the silent
shafts. This step must not be skipped or a vi-
bration may develop during engine opera-
tion.
22. Install the timing belt as follows:
a. Install the timing belt around the intake
camshaft sprocket and retain it with 2 spring
clips or binder clips.
b. Install the timing belt around the exhaust
sprocket, aligning the timing marks with the
cylinder head top surface using 2 wrenches. Re-
tain the belt with 2 spring clips. c. Install the timing belt around the idler pul-
ley, oil pump sprocket, crankshaft sprocket and
the tensioner pulley. Remove the 2 spring clips.
d. Lift upward on the tensioner pulley in a
clockwise direction and tighten the center bolt.
Make sure all timing marks are aligned.
e. Rotate the crankshaft ‘14 turn counterclock-
wise. Then, turn in clockwise until the timing
marks are alrgned again.
23. To adjust the timing (outer) belt, turn the
crankshaft ‘14 turn counterclockwise, then turn it
clockwise to move No. 1 cylinder to TDC.
24. Loosen the center bolt. Using tool
MD998738 or equivalent and a torque wrench, apply
a torque of 22-25 inch. Ibs. (2.6-2.8 Nm). Tighten
the center bolt.
25. Screw the special tool into the engine left
support bracket until its end makes contact with the
tensioner arm. At this point, screw the special tool in
some more and remove the set wire attached to the
auto tensioner, if the wire was not previously re-
moved. Then remove the specral tool.
26. Rotate the crankshaft 2 complete turns clock-
wise and let it sit for approximately 15 minutes. Then,
measure the auto tensioner protrusion (the distance
between the tensioner arm and auto tensioner body)
to ensure that it is within 0.15-0.18 in. (3.8-4.5mm).
If out of specification, repeat Step l-4 until the spec-
ified value is obtained.
27. If the timing belt tension adjustment is being
performed with the engine mounted in the vehicle,
and clearance between the tensioner arm and the auto
tensioner body cannot be measured, the following al-
ternative method can be used:
a. Screw in special tool MD998738 or equiv-
alent, until its end makes contact with the ten-
sioner arm.
b. After the special tool makes contact with
the arm, screw it in some more to retract the auto
tensioner pushrod while counting the number of
turns the tool makes until the tensioner arm is
brought into contact with the auto tensioner
body. Make sure the number of turns the special
tool makes conforms with the standard value of
21/a-3 turns.
c. Install the rubber plug to the timing belt
rear cover.
28. Install the timing belt covers and all related
items.
29. Connect the negative battery cable.
1.8L & 2.OL SOHC Engines
g See Figures 159, 160, and 161
1. Position the engine so the No. 1 piston is at
TDC of the compression stroke.
2. Disconnect the negative battery cable.
3. Remove the engine undercover.
4. Using the proper equipment, slightly raise
the engine to take the weight off the side engine
mount. Remove the engine mount bracket.
5. Remove the drive belts, tension pulley brack-
ets, water pump pulley and crankshaft pulley.
6. Remove all attaching screws and remove the
upper and lower timing belt covers.
7. Remove the timing belt covers.
8. Remove the outer crankshaft sprocket and
flange.
9. Remove the silent shaft (inner) belt tensioner
and remove the belt.

l
3-40 ENGINEANDENGINEOVERHAUL
Counterbaiance
19235861
Fig. 163 Timing belt 5 installation mark
alignment- 2.OL turbo
Do not compress the pushrod too quickly,
damage to the pushrod can occur.
21. Install the auto-tensioner on the engine.
22. Align the timing marks on the camshaft
sprocket, crankshaft sprocket and the oil pump
sprocket.
23. After aligning the mark on the oil pump
: sprocket, remove the cylinder block plug and insert a
prytool in the hole to check the position of the coun-
terbalance shaft. The orvtool should ao in at least 7. Remove the power steering pump, alternator
air conditioning compressor, tension pulley and ac-
companying brackets, as required.
8 Remove the upper front timing belt cover.
9. Remove the water pump pulley and the
crankshaft pulley(s).
10. Remove the lower timing belt cover mountinf
screws and remove the cover.
11. If the belt(s) are to be reused, mark the direc.
tion of rotation on the belt.
12. Remove the timing (outer) belt tensioner and
remove the belt. Unbolt the tensioner from the block
and remove.
13. Remove the outer crankshaft sprocket and
flange.
14. Remove the silent shaft (inner) belt tensioner
and remove the inner belt. Unbolt the tensioner from
the block and remove it.
15. To remove the camshaft sprockets, use SST
Ml39g67-01 and MlT308239, or their equivalents.
To in!3tall:
16. Install the camshaft sprockets and tighten thr
center bolt to 65 ft. Ibs. (90 Nm).
17. Align the timing mark of the silent shaft belt
sprockets on the crankshaft and silent shaft with the
marks on the front case. Wrap the silent shaft belt
around the sprockets so there is no slack in the uppe
!
I span of the belt and the timing marks are still in line.
18. Install the tensioner initially so the actual
:enter of the pulley is above and to the left of the in-
jtallation bolt. 2.36 in. (60mm) or more, if not, rotai;! the oil pump
sprocket once and realign the timing mark so the pry-
24. Install the timing belt on the intake camshaft
and secure it with a clip. .
25. Install the timina belt on the exhaust old. 2.41 Engine
I: # See Figures 164 thru 162
1. Be sure that the engine’s No. 1 piston is at
TDC in the compression stroke.
Wait at least 90 seconds after the negative
battery cable is disconnected to prevent pos-
sible deployment of the air bag.
2. Disconnect the negative battery cable.
3. Remove the spark plug wires from the tree on
the upper cover.
4. Drain the cooling system.
Never open, service or drain the radiator or
cooling system when hot; serious bums can
occur from the steam and hot coolant. Also,
when draining engine coolant, keep in mind
that cats and dogs are attracted to ethylene
glycol antifreeze and could drink any that is
left in an uncovered container or in puddles
on the ground. This will prove fatal in suffi-
cient quantities. Always dram coolant into a
sealable container. Coolant should be reused
unless it is contaminated or is several years
tool goes in. Do not remove the on/ool until the tfrn- 5. Remove the shroud, fan and accessory drive
ing belt is installed. lelts.
6. Remove the radiator as required. 19. Move the pulley up by hand so the center
jpan of the lona side of the belt deflects about 11~ in.
camshaft.
26. Align the timing marks with the cylinder head
top surface using two wrenches. Secure the belt with
another clip.
27. tnstatf the belt around the idler pulley, oil
pump sprocket, crankshaft sprocket and the tensioner
pulley.
28. Turn the tensioner pulley so the pinholes are
at the bottom. Press the pulley lightly against the tim-
ing belt.
29. Screw the special tool into the left engine
support bracket until it contacts the tensioner arm,
then screw the tool in a little more and remove the
pushrod pin from the auto-tensioner. Remove the
special tool and tighten the center bolt to 35 ft. Ibs.
(48 Nm). Fig 164 Remove the upper engine mount-
to-mount bracket nuts al%@]
Pm3p70 Fig. 165 Remove the upper engine mount
through-bolt . . .
30. Turn the crankshaft ‘Id turn counterclockwise,
then clockwise until the timing marks are aligned.
31. Loosen the center bolt. Install Mitsubishi
Special Tool MD998767, or equivalent, on the ten-
sioner p&y. Turn the tensioner pulley counterclock-
wise with a torque of 2.6 ft. Ibs. (3.5 Nm) and tighten
the center boftto 35 ft. tbs. (48 Nm). Do not let the
tensioner pUtFey turn when tightening the bolt.
32. Turn the crankshaft clockwise two revolutions
and align the timing marks.
33. After 15 minutes, measure the protrusion of
the pushrod on the auto-tensioner. The standard
measurement is 0.150-0.177 in (3.8-4.5mm). If the
I protrusion is out of specification, loosen the ten-
I sioner pulley, apply the proper torque to the belt and
: retighten the center bolt.
34. Install the timing belt covers and all applica-
i ble components.

.
3-42 ENGINEANDENGINEOVERHAUL
Fig. 180 Silent shaft alignment marks. No,
tice the tension side of the inner (silen
shaft) belt-2.41 enaine
Timing merk
(pun+ on sprocket)
liming m&k
(notch in sprocket)
79245g31 :ig. 181 Timing belt pulley alignmenl
narks-2.41 enoine
20. Hold the pulley tightly so it does not rotate
when the bolt is tlghtened. Tighten the bolt to 15 ft.
Ibs. (20 Nm). If the pulley has moved, the belt will be
too tight
21. Install the timing belt tensioner fully toward
the water pump and temporarily tighten the bolts.
Place the upper end of the spring against the water
pump body. Align the timing marks of the cam,
crankshaft and oil pump sprockets with the corre-
sponding marks on the front case or head.
*If the following steps are not followed ex-
actly, there is a chance that the silent shaft
alignment will be 180 degrees off. This will
cause a noticeable vibration in the engine
and the entire procedure will have to be re-
peated.
22. Before installing the timing belt, ensure that
the left side silent shaft is in the correct position.
*It is possible to align the timing marks on
the camshaft sprocket, crankshaft sprocket
and the oil pump sprocket with the lefl bal-
ance shaft out of alignment.
23. With the timing mark on the oil pump pulley
aligned with the mark on the front case, check the
alignment of the left balance shaft to assure correct
shaft timing. a. Remove the plug located on the left side of
the block in the area of the starter.
b. Insert a tool having a shaft diameter of 0.3
in. (8mm) into the hole.
c. With the timing marks still aligned, the tool
must be able to go in at least 2l/s in. (59mm). If
it can only go m about 1 in. (25mm), turn the oil
pump sprocket one complete revolution.
d. Recheck the position of the balance shaft
with the timing marks reahgned. Leave the tool in
place to hold the silent shaft while continuing.
24. Install the belt to the crankshaft sprocket, oil
pump sprocket and the camshaft sprocket, in that or-
der. While doing so, be sure there is no slack be-
tween the sprockets except where the tensioner will
take it up when released.
25. Recheck the timing marks’ alignment.
26. If all are aligned, loosen the tensioner mount-
ing bolt, and allow the tensioner to apply tension to
the belt.
27. Remove the tool that is holding the silent
shaft in place and turn the crankshaft clockwise a dis-
tance equal to two teeth of the camshaft sprocket.
This will allow the tensioner to automatically tension
the belt the proper amount.
Do not manually apply pressure to the ten-
sioner. This will overtighten the belt and will
cause a howling noise.
28. First tighten the lower mounting bolt and then
tighten the upper spacer bolt.
If any binding is felt when adiustino the tim-
ing delt tension by turning th;! crankshaft,
STOP turning the engine, because the pis-
tons may be hitting the valves.
29. To verify that belt tension is correct, check
that the deflection of the longest span (between the
camshaft and oil pump sprockets) is I/* in. (13mm).
30. Install the lower timing belt cover. Be sure the
packing is properly positioned in the inner grooves of
the covers when installing.
31. Install the water pump pulley and the crank-
shaft pulley(s).
32. Install the upper front timing belt cover.
33. Install the power steering pump, alternator,
air conditioning compressor, tension pulley and ac-
companying brackets, as required.
34. Install the radiator, shroud, fan and accessory
drive belts.
35. Install the spark plug wires to the tree on the
upper cover.
36. Refill the cooling system.
37. Connect the negative battery cable. Start the
engme and check for leaks.
3.OL SDHC Engine
1992-94 MODELS
# See Figures 182 and 183
1. Disconnect the negative battery cable.
2. Remove the engine undercover
3. Remove the cruise control
actuator 4. Remove the accessory drive belts. 5. Remove the air conditioner compressor ten-
sion pulley assembly.
6. Remove the tension pulley bracket.
7. Using the proper equipment, slightly raise
the engine to take the weight off the side engine
mount. Remove the engine mounting bracket.
8. Detach the power steering pump pressure
switch connector. Remove the power steering pump
and wire aside.
9. Remove the engine support bracket.
10. Remove the crankshaft pulley.
11. Remove the timing belt cover cap.
12. Remove the timing belt upper and lower cov-
ers.
13. If the same timing belt will be reused, mark
the direction of the timing belt’s rotation for installa-
tion in the same direction. Make sure the engine is
positioned so the No. 1 cylinder is at the TDC of its
compression stroke and the sprockets’ timing marks
are aligned with the engine’s timing mark indicators.
14. Loosen the timing belt tensioner bolt and re-
move the belt. If the tensioner is not being removed,
position it as far away from the center of the engine
as possible and tighten the bolt.
15. If the tensioner is being removed, paint the
outside of the spring to ensure that it is not installed
backwards. Unbolt the tensioner and remove it along
with the spring.
To install:
16. Install the tensioner, if removed, and hook the
upper end of the spring to the water pump pin and
the lower end to the tensioner in exactly the same po-
sition as originally installed. If not already done, po-
sition both camshafts so the marks align with those
on the rear. Rotate the crankshaft so the timing mark
aligns with the mark on the oil pump.
17. Install the timing belt on the crankshaft
sprocket and while keeping the belt tight on the ten-
sion side, install the belt on the front camshaft
sprocket.
18. Install the belt on the water pump pulley, then
the rear camshaft sprocket and the tensioner.
19. Rotate the front camshaft counterclockwise to
tension the belt between the front camshaft and the
crankshaft. If the tlmlng marks became misaligned,
repeat the procedure.
20. Install the crankshaft sprocket flange.
21. Loosen the tensioner bolt and allow the
spring to apply tension to the belt.
22. Turn the crankshaft 2 full turns in the clock-
wise direction until the timing marks align again.
Now that the belt is properly tensioned, torque the
tensioner lock bolt to 21 ft. Ibs. (29 Nm). Measure
the belt tension between the rear camshaft sprocket
and the crankshaft with belt tension gauge, The spec-
ification is 46-68 Ibs. (210-310 N).
23. Install the timing covers. Make sure all pieces
of packing are positioned in the inner grooves of the
covers when Installing.
24. install the crankshaft pulley. Tighten the bolt
to 108-116ft. Ibs. (150-160 Nm)
25. Install the engine support bracket.
26. Install the power steering pump and recon-
nect wire harness at the power steering pump pres-
sure switch.
27. Install the engine mounting bracket and re-
move the engine support fixture.
28. Install the tension pulleys and drive belts.
29. Install the cruise control actuator.
30 Install the engine undercover.

.
3-44 ENGINEANDENGINEOVERHALJL
31. Connect the negative battery cable.
32. Road test the vehicle.
EXCEPT 1992-94 MODELS
$ See Figure 184
1. Position the engine so the No. 1 cylinder is at
TDC of its compression stroke.
2. Disconnect the negative battery cable.
Wait at least 90 seconds after the negative
battery cable is disconnected to prevent pos-
sible deployment of the air bag.
3. Remove the engine undercover.
4. Remove the front undercover panel.
5. Remove the cruise control pump and the link
assembly.
6. Remove the alternator.
7. Raise and suspend the engine so that force is
not applied to the engme mount,
8. Remove the timing covers from the engine.
9. If the same timing belt will be reused, mark
the direction of the timing belt’s rotation for installa-
tion in the same direction. Make sure the engine is
positroned so the No. 1 cylinder is at the TDC of its
compression stroke and the timing marks are aligned
with the engine’s timing mark indicators on the valve
covers or head. 10. Loosen the center bolt of tensioner pulley and
unbolt auto-tensioner assembly The auto-tensioner
assembly must be reset to correctly adjust belt ten-
sion. Remove the timing belt.
11. Using a wrench, hold the camshaft at its
hexagon and remove the camshaft sprocket bolt.
12. Remove and position the auto-tensioner into
a vise with soft jaws. The plug at the rear of tensioner
protrudes, be sure to use a washer as a spacer to
protect the plug from contacting vise jaws.
13. Slowly push the rod Into the tensioner until
the set hole rn rod is aligned with set hole in the
auto-tensioner.
14. Insert a 0.055 in. (1.4mm) wire into the
aligned set holes. Unclamp the tensioner from the
vise and install it on the engine. Trghten tensroner to
17 ft. Ibs. (24 Nm).
15. Clean and inspect both auto tensioner
mounting bolts. Coat the threads of the old bolts with
thread sealer. If new bolts are installed, Inspect the
heads of the new bolts. If there is white paint on the
bolt head, no sealer is required. If there is no parnt on
the head of the bolt, apply a coat of thread sealer to
the bolt. Install both bolts and tighten to 17 ft. Ibs.
(24 Nm).
To install: 16. Install the tensioner, if removed, and hook the
upper end of the spring to the water pump pin and
the lower end to the tensioner in exactly the same po-
sition as originally installed. 17. Ensure both camshafts are still positioned so
the timing marks align with those on the rear timing
covers.
18. Rotate the crankshaft so the timing mark
aligns with the mark on the front cover.
19. Install the timing belt on the crankshaft
sprocket and while keeping the belt tight on the ten-
sion side, mstall the belt on the front (left) camshaft
sprocket.
20 Install the belt on the water pump pulley, then
the rear (right) camshaft sprocket and the tensioner.
21. Loosen the bolt that secures the adjustment
of the tensioner and lightly press the tensioner
against the timing belt.
22. Check that the timing marks are in alignment.
23 Rotate the crankshaft 2 full turns in the clock-
wise direction only, then realign the timing marks,
24. Tighten the bolt that secures the tensioner to
19 ft. Ibs. (26 Nm).
25. install the lower and the upper timing belt
covers, along with all other applicable components.
3.OL DDHC Engine
1992-94 MODELS
# See Figure 185
1. Position the engine so the No. 1 cylinder is at
TDC of its compression stroke.
2. Disconnect the negative battery cable.
3. Remove the engine undercover.
Timing mark
(on belt cover)
Timing belt tensioner
Crankshaft
sprocket
7923W :ig. 184 Align the sprockets properly before removing or installing the timing belt-1995-96 Diamante with the 3.OL (6672) SDHC engine

ENGINEANDENGINEOVERHAUL 3-47
DO NOT rotate or turn the camshafts when re-
moving the sprockets or severe engine dam-
age will result from internal component in-
terference.
22. Align the mark on the crankshaft sprocket
with the mark on the front case. Then, move the
crankshaft sprocket 1 tooth counterclockwise.
23. Align the timing marks of the camshafts with
the marks on the rear covers.
24. Using large paper clips to secure the timing
belt to the sprockets, install the timing belt in the fol-
lowing order. Be sure camshafts-to-cylinder heads
and crankshaft-to-front cover timing marks are
aligned. Install the timing belt around the pulleys in
the following order:
a. Exhaust camshaft sprocket (front bank).
b. Intake camshaft sprocket (front bank).
c. Water pump pulley.
d. Intake camshaft sprocket (rear bank).
e. Exhaust camshaft sprocket (rear bank).
f. Tensioner pulley.
g. Crankshaft pulley.
h. Idler pulley.
*Since the camshaft sprockets turn easily,
secure them with box wrenches when in-
stalling the timing belt.
25. Align all timing marks on the crankshaft and
raise the tensioner pulley against the belt to remove
slack, snug tensioner bolt.
26. Check the alignment of all the timing marks
and remove the clips that secure the timing belt to the
camshaft sprockets.
27. Rotate the engine 1/4 turn counterclockwise,
then rotate the engine clockwise to align the timing
marks. Check that all the timing marks are in align-
ment.
28. Loosen the center bolt on the tensioner pul-
ley.
29. Using tool MD998752 or equivalent and a
torque wrench, apply 84 inch Ibs. (10 Nm) to the tool
on the tensioner. Tighten the tensioner bolt to 35 ft.
Ibs. (49 Nm) and be sure the tensioner does not ro-
tate with the bolt. 30. Rotate the crankshaft two complete turns
clockwise and let it sit for approximately five minutes.
Then, check that the set pin can easily be inserted
and removed from the hole in the auto-tensioner.
31. Remove the set wire attached to the auto-ten-
sioner
32. Measure the auto-tensioner protrusion (the
distance between the tensioner arm and auto-ten-
sioner body) to ensure that it is within 0.15-0.18 in.
(3.8-4.5mm). If out of specification, repeat adjust-
ment procedure until the specified value is obtained.
33. Check again that the timing marks on all
sprockets are in proper alignment.
34. Install the timing belt covers and all other ap-
plicable components.
3.51 Engine
p See Figure 187
1. Disconnect the negative battery cable.
2. Drain the cooling system.
Never open, service or drain the radiator or
cooling system when hot; serious burns can
occur from the steam and hot coolant. Also,
when draining engine coolant, keep in mind
that cats and dogs are attracted to ethylene
giycoi antifreeze and could drink any that is
left in an uncovered container or in puddles
on the ground. This will prove fatal in suffi-
cient quantities. Always drain coolant into a
sealable container. Coolant should be reused
unless it is contaminated or is several years
old.
3. Remove the drive belts.
4. Remove the upper radiator shroud.
5. Remove the fan and fan pulley.
6. Without disconnecting the lines, remove the
power steering pump from its bracket and position it
to the side Remove the pump brackets.
7. Remove the belt tensioner pulley bracket.
8. Without releasing the refrigerant, remove the
air conditioning compressor from its bracket and po-
sition it to the side.
9. Remove the bracket.
Timing marks
liming marks
Tinning marks
79245934 Fig. 187 Clean the timing marks to verify their position when aligning-3.51 engine
10. Remove the cooling fan bracket.
11, On some vehicles It may be necessary to re-
move the pulley from the crankshaft to access the
lower cover bolts.
12. Remove the timing belt cover bolts and the
upper and lower covers from the engme.
13. Detach the crankshaft position sensor con-
nector
14. Using SST MB9g67-01 and MD998754, or
their equivalents, remove the crankshaft pulley from
the crankshaft.
15. Use a shop rag to clean the timing marks to
assist in properly aligning the timing marks.
16. Loosen the center bolt on the tension pulley
and remove the timing belt.
@if the same timing belt will be reused,
mark the direction of timing belt’s rotation,
for installation in the same direction. Be sure
engine is positioned so No. 1 cylinder is at
the TDC of it’s compression stroke and the
sprockets timing marks are aligned with the
engine’s timing mark indicators.
17. Remove the auto-tensioner, the tension pul-
ley and the tension arm assembly.
18. Remove the sprockets by holding the hexago-
nal portion of the camshaft with a wrench while re-
moving the sprocket bolt.
To install: 19. Install the crankshaft pulley and turn the
crankshaft sprocket timing mark forward (clockwise)
three teeth to move the piston slightly past No. 1
cylinder top dead center.
20. If removed, install the camshaft sprockets and
tighten the bolts to 64 ft. Ibs. (88 Nm).
21, Align the timing mark of the left bank side
camshaft sprocket.
22. Align the timing mark of the right bank side
camshaft sprocket, and hold the sprocket with a
wrench so that it doesn’t turn.
23. Set the timing belt onto the water pump pul-
ley.
24. Check that the camshaft sprocket timing mark
of the left bank side is aligned and clamp the timing
belt with double clips.
25. Set the timing belt onto the idler pulley.
if any binding is felt when adjusting the tim-
ing belt tension by turning the crankshaft,
STOP turning the engine, because the pis-
tons may be hitting the valves.
26. Turn the crankshaft one turn counterclock-
wise and set the timing belt onto the crankshaft
sprocket.
27. Set the timing belt on the tension pulley.
28. Place the tension pulley pin hole so that it is
towards the top. Press the tension pulley onto the
timing belt, and then provisionally tighten the fixing
bolt. Tighten the bolt to 35 ft. Ibs. (48 Nm).
29. Slowly turn the crankshaft two full turns in the
clockwise direction until the timing marks align. Re-
move the four double clips.
30. Install the crankshaft position sensor connec-
tor.
31. Install the upper and lower covers on the en-
gine and secure them with the retaining screws. Be
sure the packing is properly positioned in the inner
grooves of the covers when installing.

ENGlNEANDENGlNEOVERHALiL 3-51
:ig. 203 Camshaft, rocker arm and shaft assemblies-2.41 engine 9315393'
Intake side Exhaust side
7923PG57 Fig. 204 Camshaft identification-2.41 en-
gine
9. Remove the intake and exhaust camshafts.
10. Remove the rocker arms and lash adjusters
*It is essential that all parts be kept in the
same order and orientation for reinstallation.
In order to prevent confusion during installa-
tion, be sure to mark and separate all parts.
To install:
11. Install the lash adjusters and rocker arms into
the cylinder head. Lubricate lightly with clean oil
prior to installation.
12. Lubricate the camshafts with heavy engine oil
and position the camshafts on the cylinder head.
13 Check the camshaft journals and lobes for
wear or damage. Also, check the cylinder head oil
holes for clogging. Visually inspect the rocker arm
roller and replace if dented, damaged or evidence of
seizure is evident. Check the roller for smooth rota-
tion. Replace If excess play or binding is present.
Also, inspect the valve contact surface for possible
damage or seizure. It is recommended that all rocker
arms and lash adjusters be replaced together.
*Do not confuse the intake camshaft with
the exhaust camshaft. The intake camshaft
has a split on the rear face for driving the ,
crank angle sensor.
14. Make sure the dowel pin on both camshaft
sprocket ends are located on the top.
15. Install the bearing caps. Tighten the caps in
sequence and rn 2 or 3 steps. No 2 and 5 caps are of
the same shape. Check the markings on the caps to
identify the cap number and intake/exhaust symbol. Only 1 (intake) or I? (exhaust) is stamped on No. 1
bearing cap Also, make sure the rocker arm is cor-
rectly mounted on the lash adjuster and the valve
stem end. Torque the retaining bolts to 15 ft. Ibs. (20
Nm).
16. Apply a coating of engine oil to the oil seal.
Using the proper size driver, press-fit the seal into
the cylinder head.
17. Install the camshaft sprockets. While holding
the camshaft at its hexagon, between number 2 and 3
journals tighten sprocket bolts to 58-72 ft. Ibs.
(80-l 00 Nm).
18. Install the timing belt, covers and related
components.
19. Install the valve cover, using new gasket, and
reconnect all related components
20. Reconnect the negative battery cable.
3.OL DOHC Engine
# See Figures 205 and 206
1. Relieve the fuel system pressure.
2. Disconnect negative battery cable.
3. Remove the intake manifold plenum.
4. Remove the timing belt cover and the timing
belt.
DO NOT rotate the crankshaft or camshafts
after the timing belt has been removed. If ro-
tated, severe internal engine damage will re-
sult from the pistons hitting the valves.
5. Remove the center cover, breather, PCV
hoses, and the spark plug cables.
6. Remove the rocker cover and the semi-circu-
lar packing.
7. Matchmark the position of the crankshaft po-
sition sensor at the rear of the camshaft, then remove
the sensor.
8. If equipped with a camshaft sensor, remove
the sensor from the front of the engine.
9 Being sure to hold the flats of the camshaft,
loosen the camshaft sprocket bolts.
10. Noting the positionmg and location of the
sprockets, remove the sprockets from the camshafts.
*Be sure to note the positioning of the knock
pin at the end of the camshafts for reinstalla-
tion purposes.
*Be sure to keep the valve train components
labeled and in proper order for reassembly.
11. Loosen the bearing cap bolts in 2-3 steps.
12. Label and remove all camshaft bearing caps.
*If the bearing caps are difficult to remove,
use a plastic hammer to gently tap the com-
ponents.
13. Mark the components and remove the intake
and the exhaust camshafts.
14. Remove the rocker arms and the lash ad-
justers. Be sure to note the location of the valve train
components for reinstallation purposes.
1 semblies-3.01 DOHC engine
I
Left bank
7923PG58 Fig. 206 Proper positioning of the camshaft knock pins-3.01 DOHC engine

ENGINEANDENGINEOVERHAUL 3-57
Anything that generates heat and/or friction WIII
eventually burn or wear out (for example, a light bulb
generates heat, therefore its life span is limited). With
this in mind, a running engine generates tremendous
amounts of both; friction is encountered by the mov-
ing and rotating parts inside the engine and heat is
created by friction and combustion of the fuel How-
ever, the engine has systems designed to help reduce
the effects of heat and friction and provide added
longevrty. The oiling system reduces the amount of
friction encountered by the moving parts inside the
engine, while the cooling system reduces heat cre-
ated by friction and combustion If either system is
not maintained, a break-down will be inevitable.
Therefore, you can see how regular maintenance can
affect the service life of your vehicle, If you do not
drain, flush and refill your cooling system at the
proper intervals, deposits WIII begin to accumulate in
the radiator, thereby reducing the amount of heat it
can extract from the coolant The same applies to
your oil and filter; If it is not changed often enough it
becomes laden with contaminates and is unable to
properly lubricate the engine. This increases friction
and wear.
There are a number of methods for evaluating the
condition of your engine. A compression test can re-
veal the condition of your pistons, piston rings,
cylinder bores, head gasket(s), valves and valve
seats. An oil pressure test can warn you of possible
engine bearing, or oil pump failures. Excessrve oil
consumption, evidence of oil in the engine air intake
area and/or bluish smoke from the tailpipe may indi-
cate worn piston rings, worn valve guides and/or
valve seals. As a general rule, an engine that uses no
more than one quart of oil every 1000 miles is in
good condition. Engines that use one quart of oil or
more in less than 1000 miles should first be checked
for oil leaks. If any oil leaks are present, have them
fixed before determining how much oil is consumed
by the engine, especrally if blue smoke is not visible
at the tailpipe
COMPRESSION TEST
# See Figure 226
tccs3801 Fig. 226 A screw-in type compression gauge
is more accurate and easier to use without
an assistant
A noticeable lack of engine power, excessive oil
consumption and/or poor fuel mileage measured
over an extended period are all indicators of internal
engine wear. Worn piston rings, scored or worn
cylinder bores, blown head gaskets, sticking or burnt
valves, and worn valve seats are all possible culprits.
A check of each cylinders compression WIII help lo-
cate the problem.
*A screw-in type compression gauge is
more accurate than the type you simply hold
against the spark plug hole. Although it takes
slightly longer to use, it’s worth the effort to
obtain a more accurate reading.
1 Make sure that the proper amount and vis-
cosity of engine oil is in the crankcase, then ensure
the battery is fully charged.
2. Warm-up the engine to normal operating
temperature, then shut the engine
OFF. 3. Disable the ignition system.
4. Label and disconnect all of the spark plug
wires from the plugs,
5. Thoroughly clean the cylinder head area
around the spark plug ports, then remove the spark
plugs.
6. Set the throttle plate to the fully open (wide-
open throttle) position You can block the accelerator
linkage open for this, or you can have an assistant
fully depress the accelerator pedal.
7. Install a screw-in type compression gauge
into the No. 1 spark plug hole until the fitting is snug.
Be careful not to crossthread the spark plug
hole.
8. According to the tool manufacturers instruc-
tions, connect a remote starting switch to the starting
circuit.
9. With the ignition switch in the
OFF position,
use the remote starting switch to crank the engine
through at least five compression strokes (approxi-
mately 5 seconds of cranking) and record the highest
reading on the gauge
10. Repeat the test on each cylinder, cranking the
engine approximately the same number of compres-
sion strokes and/or time as the first.
11. Compare the hrghest readings from each
cylinder to that of the others. The indicated compres-
sion pressures are considered within specifications if
the lowest reading cylinder is within 75 percent of the
pressure recorded for the highest reading cylinder
For example, if your highest reading cylinder pres-
sure was 150 psi (1034 kPa), then 75 percent of that
would be 113 psi (779 kPa). So the lowest reading
cylinder should be no less than 113 psi (779 kPa).
12. If a cylinder exhibits an unusually low com-
pression reading, pour a tablespoon of clean engine
oil into the cylinder through the spark plug hole and
repeat the compression test. If the compression rises
after adding oil, it means that the cylinder’s piston
rings and/or cylinder bore are damaged or worn, If
the pressure remains low, the valves may not be seat-
ing properly (a valve job is needed), or the head gas-
ket may be blown near that cylinder. If compression in any two adjacent cylinders is low, and if the addi-
tion of oil doesn’t help raise compression, there is
leakage past the head gasket. Oil and coolant in the
combustion chamber, combined with blue or con-
stant white smoke from the tailpipe, are symptoms of
this problem. However, don’t be alarmed by the nor-
mal white smoke emitted from the tailpipe during en-
gine warm-up or from cold weather driving. There
may be evidence of water droplets on the engine dip-
stick and/or oil droplets in the cooling system if a
head gasket is blown.
OIL PRESSURETEST
Check for proper oil pressure at the sending unit
passage with an externally mounted mechanical oil
pressure gauge (as opposed to relying on a factory
Installed dash-mounted gauge). A tachometer may
also be needed, as some specifications may require
running the engine at a specific rpm.
1. With the engine cold, locate and remove the oil
pressure sending unit.
2. Followrng the manufacturers instructions,
connect a mechanical oil pressure gauge and, if nec-
essary, a tachometer to the engine.
3 Start the engine and allow it to idle.
4 Check the oil pressure reading when cold and
record the number. You may need to run the engine
at a specified rpm, so check the specifications,
5. Run the engine until normal operating temper-
ature is reached (upper radiator hose will feel warm)
6. Check the oil pressure reading again with the
engine hot and record the number. Turn the engine
OFF. 7. Compare your hot oil pressure reading to that
given in the chart If the reading is low, check the
cold pressure reading against the chart. If the cold
pressure IS well above the specification, and the hot
reading was lower than the specification, you may
have the wrong viscosity oil in the engine. Change
the oil, making sure to use the proper grade and
quantity, then repeat the test.
Low oil pressure readings could be attributed to
internal component wear, pump related problems, a
low oil level, or oil viscosity that is too low. High oil
pressure readings could be caused by an overfilled
crankcase, too htgh of an oil viscosity or a faulty
pressure relief valve.
Now that you have determined that your engine is
worn out, you must make some decisions. The ques-
tion of whether or not an engine IS worth rebuilding
is largely a subjective matter and one of personal
worth. Is the engine a popular one, or IS it an obso-
lete model? Are parts available? Will it get acceptable
gas mileage once It is rebuilt? Is the car its being put
into worth keeping? Would it be less expensive to
buy a new engine, have your engine rebuilt by a pro,
rebuild it yourself or buy a used engine from a sal-
vage yard? Or would It be simpler and less expensive
to buy another car? If you have considered all these
matters and more, and have still decided to rebuild
the engine, then it is time to decide how you will re-
build it.

3-60 ENGINE/
-w
remove any covers remaining on the engine such as
on today’s automobiles: the Overhead Valve (OHV)
and the Overhead Camshaft (OHC). The latter can
also be broken down into two subgroups: the Single the rocker arm, front or timing cover and oil pan.
Overhead Camshaft (SOHC) and the Dual Overhead
Camshaft (DOHC). Generally, if there is only a single
camshaft on a head. it is iust referred to as an OHC Some front covers may require the vibration damper
and/or crank pulley to be removed beforehand. The
idea is to reduce the engine to the bare necessities
(cylinder head(s), valve train, engine block, crank-
shaft, pistons and connecting rods), plus any other
‘in block’ components such as oil pumps, balance
shafts and auxiliary shafts.
Finally, remove the cylinder head(s) from the en-
gine block and carefully place on a bench. Disassem-
bly instructions for each component follow later in
this section.
There are two basic types of cylinder heads used
Most cylinder heads these days are made of an
aluminum alloy due to its light weight, durability and
L--L I _--- 1^- _..^ I:,:^^ I I ^...^. .^_ ^^^I :_-_ ..^^ ,L- same environment. The same goes for any other unchanged. One aspect to pay attention to is careful
component on the cylinder head. Think of it as an in- labeling of the parts on the dual camshaft cylinder
“’ surance policy against future problems related to that head. There will be an intake camshaft and followers
component. as well as an exhaust camshaft and followers and
Unfortunately, the only way to find out which com- they must be labeled as such. In some cases, the
ponents need replacing, is to disassemble and care- components are identical and could easily be in-
fully check each piece. After the cylinder head(s) are stalled incorrectly. DO NOT MIX THEM UP! Deter-
disassembled, thoroughly clean all of the compo- mining which is which is very simple; the intake
nents. camshaft and components are on the same side of
DISASSEMBLY the head as was the intake manifold. Conversely, the
exhaust camshaft and components are on the same
side of the head as was the exhaust manifold.
ti See Figures 237 and 238
Whether it is a single or dual overhead camshaft Cup Type Camshaft Followers
cylinder head, the disassembly procedure is relatively 6 See Figures 239, 240, and 241
t “” ““’ 1 Most cylinder heads with cup type camshaft fol-
1 1 head. Also, an engine with an OHV cylinder head is j:, ’
I also known as a pushrod engine. : .; :-,
_I lowers will have the valve spring, retainer and locks
recessed within the followers bore. You will need a
C-clamp style valve spring compressor tool, an OHC
spring removal tool (or equivalent) and a small mag-
net to disassemble the head.
1. If not already removed, remove the camshaft(s)
and/or followers, Mark their positions for assembly.
2. Position the cylinder head to allow use of a C-
clamp style valve spring compressor tool.
IIRN il~llSlt?l ~Lldll~l~S. IlUWttVtJ, MS1 11011 W8S lilt: material of choice in the past, and is still used on
many vehicles today. Whether made from aluminum
or iron, all cylinder heads have valves and seats.
Some use fwo valves per cylinder, while the more hi-
tech engines will utilize a multi-valve configuration
using 3‘4 and even 5 valves per cylinder. When the
valve contacts the seat, it does so on precision ma-
chined surfaces, which seals the combustion cham-
ber, All cylinder heads have a valve guide for each
valve. The auide centers the valve to the seat and al-
lows it to move up and down within it. The clearance
between the valve and guide can be critical. Too
much clearance and the engine may consume oil,
lose vacuum and/or damaae the seat. Too little. and
the valve can stick in the guide causing the engine to
run poorly if at all, and possibly causing severe dam-
age. The last component all cylinder heads have are
valve springs. The spring holds the valve against its
seat. It also returns the valve to this position when
the valve has been opened by the valve train or
camshaft. The spring is fastened to the valve by a re-
tainer and valve locks (sometimes called keepers).
Aluminum heads will also have a valve spring shim
to keep the spring from wearing away the aluminum. Fig, 237 Exploded view of a valve, seal,
1 cylinder head ----r- 1 spring, retamer and locks from an OHC
An ideal method of rebuilding the cylinder head
would involve replacing all of the valves, guides,
seats, springs, etc. with new ones. However, depend-
ing on how the engine was maintained, often this is
not necessary. A major cause of valve, guide and seat
wear is an improperly tuned engine. An engine that is
~~f~t~~ rich, will often wash the lubricating oil
out ofthe guide with gasoline, causing it to wear
~~fdfy. lonely, an engine which is running too
lean wifl pface higher combustion temperatures on
Me valves and seats allowing them to wear or even
bum. Springs fall victim to the driving habits of the
f~~iduaf. A driver who often runs the engine rpm to
tfre redfine will wear out or break the springs faster
then one tfrat stays well below it. Unfortunately,
mileage takes it tot1 on all of the parts. Generally, the
valves, guides, springs and seats in a cylinder head
can be machined and re-used, saving you money.
.However, if a valve is burnt, it may be wise to replace
all of the valves, since they were all operating in the oi a multi-valve cylinder
t has 2 intake
and 2 ex-
At is preferred to position the cylinder head lasket’surtace facing you with tee valve
springs facing the opposite direction and the
lead laying horizontal.
3. With the OHC spring removal adapter tool po-
,itioned inside of the follower bore, compress the
alve spring using the C-clamp style valve spring
:ompressor.
tcca3p51 fig. 239 C-clamp type spring compressor
and an OHC spring removal tool (center) for
cup type followers
Fig. 240 Most cup type follower cylinder
/ heads retain the camshaft using bolt-on
bearing caps

.
3-62 ENGINEANDENGINEOVERHAUL
lge. To accurately inspect them, you will need some
,pecialized tools:
l A O-l in. micrometer for the valves l A dial indicator or inside diameter gauge for
he valve guides
l A spring ressure test gau e
If you do no P Yl have access to t e proper tools,
‘ou may want to bring the components to a shop
hat does.
lalves
1 See Figures 251 and 252
The first thing to inspect are the valve heads. Look
E :losely at the head, margin and face for any cracks,
rxcessive wear or burning. The margin is the best
)lace?o look for burning. It should have a squared E
c
edge with an even width all around the diameter.
When a valve burns, the margin will look melted and
the edges rounded. Also inspect the valve head for
any signs of tulipping. This will show as a lifting of
the edges or dishing in the center of the head and will
usually not occur to all of the valves. All of the heads
should look the same, any that seem dished more
than others are probably bad. Next, inspect the valve
lock grooves and valve tips. Check for any burrs
around the lock grooves, especially if you had to file
them to remove the valve. Valve tips should appear
flat, although slight rounding with high mileage en-
gines is normal. Slightly worn valve tips will need to
be machined flat. last, measure the valve stem diam-
eter with the micrometer. Measure the area that rides
within the guide, especially towards the tip where
most of the wear occurs. Take several measurements along its length and compare them to each other.
Wear should be even along the length with little to no
taper. If no minimum diameter is given in the specifi-
cations, then the stem should not read more than
0.001 in. (0.025mm) below the unworn area of the
valve stem. Any valves that fail these inspections
should be replaced.
Springs, Retainers and Valve Locks
$ See Figures 253 and 254
The first thing to check is the most obvious, bro-
ken springs. Next check the free length and square-
ness of each spring. If applicable, insure to distin-
guish between intake and exhaust springs. Use a
ruler and/or carpenter’s square to measure the length.
A carpenter’s square should be used to check the
lCZS3144
I I hrnknn itc Fig. 251 Valve stems may be rolled on a flat Fio. 252 Use a micrometer
suhace to check for bends
valve stem diameter r to check the
I
There are seve Cylinder Head
ral things to check on the cylinder
head: valve guides, seats, cylinder head surface flat-
ness, cracks and physical damage.
VA1 YE GUIDES
N See Figure 255
Now that you know the valves are good, you can
254 Check the valve spring fo
s on a flat surface; a carpenter use them to check the guides, although a new valve,
if available, is preferred. Before you measure any-
thing, look at the guides carefully and inspect them
for any cracks, chips or breakage. Also if the guide is
a removable style (as in most aluminum heads),
check them for any looseness or evidence of move-
ment. All of the guides should appear to be at the
same height from the spring seat. If any seem lower
(or higher) from another, the guide has moved.
Mount a dial indicator onto the sorina side of the
cylinder head. Lightly oil the valve stem and insert it

ENGINEANDENGINEOVERHAUL 3-63
Place a straightedge across the gasket surface. Valves
Using feeler gauges, determine the clearance at the
center of the straightedge and across the cylinder Any valves that were not replaced should be
head at several points. Check along the centerline refaced and the tips ground flat. Unless you have ac-
and diagonally on the head surface. If the warpage cess to a valve grinding machine, this should be
exceeds 0.003 in. (0.076mm) within a 6.0 in. done by a machine shop. If the valves are in ex-
(152cm) span, or 0.006 in. (0.152mm) over the total tremely good condition, as well as the valve seats
length of the head, the cylinder head must be resur- and guides, they may be lapped in without petform-
,
I mg macnme worK.
4
It is a recnmmended practice to lap the valves faced. After resurfacing the heads of a V-type engine
the intake manifold flange surface should be checker,
and if necessary, milled proportionally to allow for
the change in its mounting position. _ - _ _ _ .- - - _
even after machine work has been p&formed and/or
new valves have been purchased. This insures a pos-
itive seal between the valve and seat.
-guide clearance; the 1
read
. .
into the cylinder head. Position the dial indicator
against the valve stem near the tie and zero the
gauge. Grasp the valve stem and’wiggle towards and
away from the dial indicator and observe the read-
ings. Mount the dial indicator 90 degrees from the
initial point and zero the gauge and again take a read-
ing. Compare the two readings for a out of round
condition. Check the readings against the specifica-
tions given. An Inside Diameter (I.D.) gauge designed
for valve guides will give you an accurate valve guide
bore measurement. If the I.D. gauge is used, compare
the readings with the specifications given. Any CRACKS AND PHYSICAL DAMAGE
Generally, cracks are limited to the combustion
chamber, hbwever, it is not uncommon for the head
to crack in a spark plug hole, port, outside of the
head or in the valve spring/rocker arm area. The first
area to inspect is always the hottest: the exhaust
.I *
seawpon area.
8 I .,“““I llly”Lv”l~ .ml”“l” - plr”llll”“, ““I ,“a’
because you don’t see a crack does not mean it is not
there. Some more reliable methods for inspecting for
cracks include Magnaflux? a magn$i,c process or
Zyglo? a dye penetrant. Ma{ -’
InatluxW IS used only on
ferrous metal (cast iron) heat Is. Zyglo@ uses a spray
on fluorescent mixture along with a black light to re-
veal the cracks. It is strongly recommended to have
your cylinder head checked professionally for cracks,
especially if the engine was known to have over-
I .* I,. ..^.. LAPPING THE VALVES
*Before iaoaino the valves to the seats,
read the rest of the cylinder head section to
insure that any related parts are in accept-
able enough condition to continue.
*Before anv valve seat machining and/or
lapping can be performed, the guides must
be within factory recommended specifica-
tions.
1. Invert the cylinder head.
2. Linhtlv Iuhrir;rB the valve stems and insert
-. _ ~ . . . . . .--.._-._
them into the cylinder head in their numbered order.
3. Raise the valve from the seat and apply a small
amount of fine lanninn compound to the seat.
4.
i guides that fail these inspections should be replaced nearea analor ieaKea or consumea coolant. Contact a Moisten the suction head of a hand-lapping
tool and attach it to the head of the valve.
i or machined. local shop for availability and pricing of these ser-
5. Rotate the tool between the palms of both
I vices.
I
VALVE SEATS Physical damage is usually very evident. For ex- hands, changing the position of the valve on the
valve seat and lifting the tool often to prevent groov-
A visual inspection of the valve seats should show
amnb P hrnbn mntlntinn ear from dropping the I and/or bolt. All of these ing.
.a,... . 6. Lap the valve until a smooth, polished circle is
a slightly worn and pitted surface where the valve
face contacts the seat. Inspect the seat carefully for
severe pitting or cracks. Also, a seat that is badly
worn will be recessed into the cylinder head. A se-
verely worn or recessed seat may need to be re- uetecIs SIIOUIO oe nxea or, IT unrepairaole, me neaa
should be replaced.
Camshaft and Followers evid
7
traces of the grinding corn
to maintain its lapped loca lent on the valve and seat.
‘. Remove the tool and the valve. Wipe away all
pound and store the valve
placed: All cracked seats must be replaced. A seat
concentricity gauge, if available, should be used to
check the seat run-out. If run-out exceeds specifica-
tions the seat must be machined (if no soecification
is given use 0.002 in. or O.O51mt$. Inspect the camshaft(s) and followers as described
earlier in this section.
REFINISHING & REPAIRING Do not get the valves out of order after they
have been lapped. They must be put back
: ..^^ I... --I:^:-L!-- --A
Many of the procedures gIveI
WI WIIIIISIIIIIIJ ~IIU repairing the cylinder head components must be per-
formed by a machine shop. Certain steps, if the in-
spected part is not worn, can be performed yourself
inexpensively. However, you spent a lot of time and
effort so far, why risk trying to save a couple bucks if
you might have to do it all over again?
I- with the same valve seat with which they
were lapped.
Springs, Retainers and Valve locks
There is no repair or refinishing possible with the
springs, retainers and valve locks. If they are found to
be worn or defective, they must be replaced with new
lor known nnod narts CYLtNDEt? HEAD SURFACE FLATNESS
) See Figures 256 and 257
After you have cleaned the gasket surface of the
cylinder head of any old gasket material, check the
head for flatness.
\- - a---r r- .-.
Cylinder Head
Most refinishing procedures dealing with the
VALVE GWDE
elf any machining or replacements are
e valve guides, the seats must be
Fig. 257 Checks should also be made along Unless the valve guides need machining or re-
placing, the only service to perform is to thoroughly‘
clean them of any dirt or oil residue.