1900 MITSUBISHI DIAMANTE engine coolant

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.

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.

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.

ENGINEAND ENGINEOVERHAUL 3-59
Most of the cleaning process can be carried out
with common hand tools and readily available sol-
vents or solutions. Carbon deposits can be chipped
away using a hammer and a hard wooden chisel. Old
gasket material and varnish or sludge can usually be
removed using a scraper and/or cleaning solvent. Ex-
tremely stubborn deposits may require the use of a
power drill wrth a wire brush. If using a wire brush,
use extreme care around any critical machined sur-
faces (such as the gasket surfaces, bearing saddles,
cylinder bores, etc.). USE OF A WIRE BRUSH IS NOT
RECOMMENDED ON ANY ALUMINUM COMPO-
NENTS Always follow any safety recommendations
given by the manufacturer of the tool and/or solvent.
You should always wear eye protection during any
cleaning process involvrng scraping, chipping or
spraying of solvents.
An alternative to the mess and hassle of cleaning
the parts yourself is to drop them off at a local garage
or machine shop. They will, more than likely, have
the necessary equrpment to properly clean all of the
parts for a nominal fee.
Always wear eye protection during any clean-
ing process involving scraping, chipping or
spraying of solvents.
Remove any oil galley plugs, freeze plugs and/or
pressed-in bearings and carefully wash and degrease
all of the engine components including the fasteners
and bolts. Small parts such as the valves, springs,
etc., should be placed in a metal basket and allowed
to soak. Use pipe cleaner type brushes, and clean all
passageways in the components. Use a ring ex-
pander and remove the rings from the pistons. Clean
the piston ring grooves with a special tool or a piece
of broken ring Scrape the carbon off of the top of the
piston. You should never use a wire brush on the
pistons. After preparing all of the piston assemblies
in this manner, wash and degrease them again.
Use extreme care when cleaning around the
cylinder head valve seats. A mistake or slip
may cost you a new seat.
When cleaning the cylinder head, remove carbon
from the combustron chamber with the valves in-
stalled. This will avoid damaging the valve seats.
:ig. 234 Drill out the damaged threads with
he specified size bit. Be sure to drill corn.
rletely through the hole or to the bottom oi
I blind hole REPAIRING DAMAGEDTHREADS
# See Figures 232, 233, 234, 235 and 236
Several methods of repairing damaged threads are
available Heli-Coil@ (shown here), Keenserts@ and
Microdop are among the most widely used. All in-
volve basically the same principle-drilling out
stripped threads, tapping the hole and installing a
prewound insert-making welding, plugging and
oversize fasteners unnecessary.
Two types of thread repair inserts are usually sup-
plied: a standard type for most inch coarse, rnch fine,
metric course and metrrc fine thread sizes and a
spark lug type to fit most spark plug port sizes. Con-
sult the individual tool manufacturers catalog to de-
termine exact applications. Typical thread repair kits
will contain a selection of prewound threaded inserts,
a tap (corresponding to the outside diameter threads
of the insert) and an installation tool. Spark plug in-
serts usually differ because they require a tap
equipped wrth pilot threads and a combined
reamer/tap section. Most manufacturers also supply
blister-packed thread repair Inserts separately in ad-
dition to a master kit containing a variety of taps and
inserts plus installation tools
Before attempting to repair a threaded hole, re-
move any snapped, broken or damaged bolts or
studs. Penetrating oil can be used to free frozen
threads. The offending item can usually be removed
with locking pliers or using a screw/stud extractor.
After the hole is clear, the thread can be reparred, as
shown in the series of accompanying illustrations
and in the krt manufacturers instructions.
THREADED
lCCS3039
replaced with thread repair inserts
:ig. 235 Using the kit, tap the hole in order
o receive the thread insert. Keep the tap
veil oiled and back it out frequently to avoid
:logging the threads
To properly rebuild an engine, you must first re-
move it from the vehicle, then disassemble and diag-
nose it. Ideally you should place your engine on an
engine stand. This affords you the best access to the
engine components. Follow the manufacturers direc-
tions for using the stand with your particular engine.
Remove the flywheel or flexplate before installing the
engine to the stand.
Now that you have the engine on a stand, and as-
suming that you have drained the oil and coolant
from the engine, it’s time to strip it of all but the nec-
essary components. Before you start disassembling
the engine, you may want to take a moment to draw
some pictures, or fabricate some labels or containers
to mark the locations of various components and the
bolts and/or studs which fasten them. Modern day
engines use a lot of little brackets and clips which
hold wiring harnesses and such, and these holders
are often mounted on studs and/or bolts that can be
easily mixed up. The manufacturer spent a lot of time
and money designing your vehicle, and they wouldn’t
have wasted any of it by haphazardly placing brack-
ets, clips or fasteners on the vehicle. If it’s present
when you disassemble it, put it back when you as-
semble, you will regret not remembering that little
bracket which holds a wire harness out of the path of
a rotating part.
You should begin by unbolting any accessories
still attached to the engine, such as the water pump,
power steering pump, alternator, etc. Then, unfasten
any manifolds (intake or exhaust) which were not re-
moved during the engine removal procedure. Finally,
Fig. 233 Standard thread repair insert (left),
and spark plug thread insert
im3043 Fig. 236 Screw the insert onto the installer
1001 until the tang engages the slot. Thread
‘he insert into the hole until it is l/4-l/~ turn
lelow the top surface, then remove the tool
and break off the tano usina a uunch

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.

3-66 ENGINEANDENGINEOVERHAUL
should be performed on all of the components, but
just because you don’t see a crack does not mean it
is not there. Some more reliable methods for inspect-
ing for cracks include Magnaflux? a magnetic
process or Zyglo@‘, a dye penetrant. Magnaflux@ is
used only on ferrous metal (cast iron). Zyglo@ uses a
spray on fluorescent mixture along with a black light
to reveal the cracks. It is strongly recommended to
have your engine block checked professionally for
cracks, especially if the engine was known to have
overheated and/or leaked or consumed coolant. Con-
tact a local shop for availability and pricing of these
services.
Engine Block
ENGINE BLOCK BEARING ALIGNMENT
Remove the main bearing caps and, if still in:
stalled, the main bearing inserts. Inspect all of the
main bearing saddles and caps for damage, burrs or
high spots. If damage is found, and it is caused from
a spun main bearing, the block will need to be align-
bored or, if severe enough, replacement. Any burrs or
high spots should be carefully removed with a metal
file.
Place a straightedge on the bearing saddles, in the
engine block, along the centerline of the crankshaft. If
any clearance exists between the straightedge and the
saddles, the block must be align-bored.
Align-boring consists of machining the main
bearing saddles and caps by means of a flycutter that
runs through the bearing saddles.
DECK FLATNESS
The top of the engine block where the cylinder
head mounts is called the deck. Insure that the deck
surface is clean of dirt, carbon deposits and old gas-
ket material. Place a straightedge across the surface
of the deck along its centerline and, using feeler
gauges, check the clearance along several points. Re-
peat the checking procedure with the straightedge
placed along both diagonals of the deck surface. If
the reading exceeds 0.003 in. (0.076mm) within a 6.0
in. (152cm) span, or 0.006 in. (0.152mm) over the
total length of the deck, it must be machined.
CYLINDER BORES
$ See Figure 261
The cylinder bores house the pistons and are
slightly larger than the pistons themselves. A com-
mon piston-to-bore clearance is 0.0015-0.0025 in. (0.0381mm-O.0635mm). Inspect and measure the
cylinder bores. The bore should be checked for out-
of-roundness, taper and size. The results of this in-
spection will determine whether thecylinder can be
used in its existing size and condition, or a rebore to
the next oversize is required (or in the case of remov-
able sleeves, have replacements installed).
The amount of cylinder wall wear is always greater
at the top of the cylinder than at the bottom. This
wear is known as taper. Any cylinder that has a taper
of 0.0012 in. (0.305mm) or more, must be rebored.
Measurements are taken at a number of positions in
each cylinder: at the top, middle and bottom and at

two points at each position; that is, at a point 90 de-
grees from the crankshaft centerline, as well as a
point parallel to the crankshaft centerline. The mea-
surements are made with either a special dial indica-
tor or a telescopic gauge and micrometer. If the nec-
essary precision tools to check the bore are not
available, take the block to a machine shop and have
them mike it. Also if you don’t have the tools to check
the cylinder bores, chances are you will not have the
necessary devices to check the pistons, connecting
rods and crankshaft. Take these components with you
and save yourself an extra trip.
For our procedures, we will use a telescopic
gauge and a micrometer. You will need one of each,’
with a measuring range which covers your cylinder
bore size.
1, Position the telescopic gauge in the cylinder
bore, loosen the gauges lock and allow it to expand.
*Your first two readings will be at the top of
the cylinder bore, then proceed to the middle
and finally the bottom, making a total of six
measurements.

2. Hold the gauge square in the bore, 90 degrees
from the crankshaft centerline, and gently tighten the
lock. Tilt the gauge back to remove it from the bore.
3. Measure the gauge with the micrometer and
record the reading.
4. Again, hold the gauge square in the bore, this
time parallel to the crankshaft centerline, and gently
tighten the lock. Again, you will tilt the gauge back to
remove it from the bore.
5. Measure the gauge with the micrometer and
record this reading. The difference between these two
readings is the out-of-round measurement of the
cylinder.
6. Repeat steps 1 through 5, each time going to
the next lower position, until you reach the bottom of
the cylinder. Then go to the next cylinder, and con-
tinue until all of the cylinders have been measured.
The difference between these measurements will
tell you all about the wear in your cylinders. The
measurements which were taken 90 degrees from the
crankshaft centerline will always reflect the most
wear.,That is because at this position is where the en-
gine power presses the piston against the cylinder
bore the hardest. This is known as thrust wear. Take
your top, 90 degree measurement and compare it to
your bottom, 90 degree measurement. The difference
between them is the taper. When you measure your
pistons, you will compare these readings to your pis-
ton sizes and determine piston-to-wall clearance. crankshaft, but you should hardly feel them with your
fingernail. When measuring the crankshaft with a mi-
crometer, you will take readings at the front and rear
of each journal, then turn the micrometer 90 degrees
and take two more readings, front and rear. The dif-
ference between the front-to-rear readings is the jour-
nal taper and the first-to-90 degree reading is the
out-of-round measurement. Generally, there should
be no taper or out-of-roundness found, however, up
to 0.0005 in. (0.0127mm) for either can be over-
looked. Also, the readings should fall within the fac-
tory specifications for journal diameters.
If the crankshaft journals fall within specifications,
it is recommended that it be polished before being
returned to service. Polishing the crankshaft insures
that any minor burrs or high spots are smoothed,
thereby reducing the chance of scoring the new bear-
ings.
Pistons and Connecting Rods
PISTONS
N See Figure 262
The piston should be visually inspected for any
signs of cracking or burning (caused by hot spots or
detonation), and scuffing or excessive wear on the
skirts. The wrist pin attaches the piston to the con-
netting rod. The piston should move freely on the
wrist pin, both sliding and pivoting. Grasp the con-
netting rod securely, or mount it in a vise, and try to
rock the piston back and forth along the centerline of
the wrist pin. There should not be any excessive play
evident between the piston and the pin. If there are C-
clips retaining the pin in the piston then you have
wrist pin bushings in the rods. There should not be
any excessive play between the wrist pin and the rod
bushing. Normal clearance for the wrist pin is ap-
prox. 0.001-0.002 in. (0.025mm-0.051mm).
Use a micrometer and measure the diameter of the
piston, perpendicular to the wrist pin, on the skirt.
Compare the reading to its original cylinder measure-
ment obtained earlier. The difference between the two
readings is the piston-to-wall clearance. If the clear-
ante is within specifications, the piston may be used
as is. If the piston is out of specification, but the bore
is not, you will need a new piston. If both are out of
specification, you will need the cylinder rebored and
oversize pistons installed. Generally if two or more
pistons/bores are out of specification, it is best to re-
bore the entire block and purchase a complete set of
oversize pistons.
Crankshaft
Inspect the crankshaft for visible signs of wear or
damage. All of the journals should be perfectly round
and smooth. Slight scores are normal for a used

ENGINEANDENGINEOVERHAUL 3-69
STARTING THE ENGINE
clearance using the ring and a Now that the engine is installed and every wire and
hose is properly connected, go back and double
check that all coolant and vacuum hoses are con-
, netted. Check that your oil drain plug is installed and
tt tl
C ti
hYs3222 Fig. 271 Most rings are marked to show
which side of the ring should face up when
installed to the piston
J
4. Allow the engine to reach normal operating
?mperature (the upper radiator hose will be hot to
ie touch).
5. At this point you can perform any necessary
hecks or adjustments, such as checking the ignition
ming.
6. Install any remaining components or body
anels which were removed.
IREAKING IT IN
Make the first miles on the new engine, easy ones.
arv the soeed but do not accelerate hard. Most im-
oriantly, do not lug the engine, and avoid sustained
igh speeds until at least 100 miles. Check the en-
ine oil and coolant levels frequently. Expect the en-
ine to use a little oil until the rings seat. Change the
il and filter at 500 miles, 1500 miles, then every