1900 MITSUBISHI DIAMANTE Repair Manual

.
3-52 ENGINEANDENGINEOVERHAUL
15. Check the camshaft journals for wear or dam-
age. Check the cam lobes for damage. Also, check
the cylinder head oil holes for clogging.
To install:
*Lubricate the valve train components with
clean engine oil.
16. Bleed and install the lash adjusters to the to
the original bores in the cylinder head.
17. Install the rocker arms to the cylinder head.
18. Lubricate the camshafts with clean engine oil
and position the camshafts on the cylinder head
Be sure to properly position the knock pins of
the camshaft to prevent valve to piston inter-
ference.
*Do not confuse the intake camshaft with
the exhaust camshaft. The intake camshaft
on the Diamante has a B or J stamped on the
hexagon depending on the application. The
exhaust camshaft on the Diamante has a D or
K stamped on the hexagon depending on ap-
plication.
-Install the bearing caps according to the
identification mark and cap number. Bearing
caps No. 2,3 and are marked as such. The
caps also are marked I for intake or E for ex-
haust.
19 Install the bearing caps. Tighten the caps in
sequence, gradually in 2 or 3 steps Caps 2,3 and 4
have a front mark. Install with the mark aligned with
the front mark on the cylinder head. Torque the re-
taining bolts for caps No. 2,3 and 4 to 8 ft. Ibs. (11
Nm) and torque the retaining bolts for the front and
rear caps to 14 ft. Ibs. (20 Nm).
20. Apply a coating of engine oil to the oil seals
and install the oil seals to the front and rear of the
camshafts.
21. Holding the flats of the camshaft, install and
tighten the sprocket bolts to 65 ft. Ibs. (90 Nm).
22. If removed, install the camshaft position sen-
sor and tighten the mounting bolts to 78 inch Ibs. (9
Nm).
23. Aligning the matchmark, install the crankshaft
position sensor at the rear of the camshaft and
tighten the mountrng nut to 7 ft. Ibs. (12 Nm).
24. Align the marks on the camshaft and crank-
shaft sprockets. Install the timing belt assembly.
25. Install the rocker cover and the semi-circular
packing.
26. Install the intake manifold plenum.
27. Install the spark plug cables, center cover,
breather and PCV hoses.
28. Connect the negative battery cable and check
for leaks.
3.OL SDHC Engine
ti See Figures 207, 208, 209, and 210
1. Disconnect the negative battery cable,
2. Rotate and position the engine to TDC of
compression stroke.
3. If removing the right side (front) camshaft,
matchmark the distributor rotor and distributor hous-
ing to the engine block and remove the distributor.
4. Remove the Intake manifold plenum stay
bracket. Fig. 207 Camshaft, rocker arm and shaft as-
iemblies-3.01 SDHC engine
Siit 7923'659 Fig. 208 Right bank camshafl identifica-
tion-3.01 SDHC engine
Right bank
Left bank
7923PG60 Fig. 209 Proper positioning of the
:amshafts-3.OL SDHC enoine

Tmng bolt side Armwmark(cql~ndertmad)
7923PG61
:ig. 210 Alignment of the rocker shafts and application of sealant-3.01 SDHC engine
5. Remove the distributor housing adapter and
,. ,.^.
bearmg caps, as an assembly 11. Remove the rocker arms, rocker shafts and
aiscara tne u-rmg.
^ -
6; Kemove the valve covers and the tlmmg belt.
7 Using camshaft sprocket holding tool
MB9g67 and MD998719 or equivalent, hold the
sprocket and loosen the bolt.
8. Remove the bolt and note the positioning of
the of the knock pin at the end of the camshaft and
remove the sprocket.
9. Install auto lash adjuster retainer tools
MD998443 or equivalent, on the rocker arms.
*Be sure to note the position of the rocker
arms, rocker shafts and bearing caps for re-
installation purposes.
10 Remove the camshaft bearing caps but do not
remove the bolts from the caps. 12. Remove the camshaft from the cylinder head.
13. Inspect the bearing journals on the camshaft,
cylinder head, and bearing caps.
To install:
*The right bank camshaft is identified by a
4mm slit at the rear end of the camshaft.
14. Lubricate the camshaft journals and camshaft
with clean engme oil and install the camshaft in the
cylinder head Be sure to properly position the knock
pin of the camshaft as noted during removal.
15. Apply sealer at the ends of the bearing caps
and install the rocker arms, rocker shafts and bearing
caps as an assembly Properly positron the arrows on
the bearing caps.

ENGINEANDENGINEOVERHAUL 3-53
16. Torque the bearing cap bolts in the following
sequence: No. 3, No. 2, No. 1 and No. 4 to 85 inch
Ibs. (10 Nm).
17. Repeat the sequence increasing the torque to
14 ft. Ibs. (20 Nm).
18. Remove the auto lash adjuster retainer tools
from the rocker arms.
19. Install the camshaft sprocket and bolt.
20. Using camshaft sprocket holding tool
MB9g67 and MD998719 or equivalent, hold the
sprocket and tighten the bolt to 65 ft. Ibs. (90 Nm).
21. Install the timing belt and valve covers.
22. Using a new O-ring, install the distributor ex-
tension housing.
23. Install the intake manifold plenum stay
bracket.
24. Install the distributor assembly Be sure to
align the rotor and distributor housing matchmarks.
25. Connect the negative battery cable and check
for leaks.
3.5L Engine
+ See Figures 211 and 212
1. Disconnect the negative battery cable.
2. Remove the timing belt. Refer to the timing
belt procedure in this section.
3. Remove the rocker arm cover.
4. Install the lash adjuster clips on the rocker
arms, then loosen the bearing cap bolts. Do not re-
move the bolts from the bearing caps.
5. Remove the rocker arms, shafts and bearing
caps as an assembly.
6. Remove the camshafts.
To install: 7. Lubricate the camshafts with engine oil and
position them on the cylinder heads.
8. Position the dowel Dins as shown in the
drawing.
9. Install the bearing caps/rocker arm assem-
blies. Tighten the bolts to 23 ft. Ibs. (31 Nm).
10. hstall the rocker arm cover using a new gas-
ket.
11. Install the timing belt and remaining compo-
nents Refer to the timing belt procedure in this sec-
tion.
12. Connect the negative battery cable.
INSPECTION
Camshaft Lobe Liff
Camshaft lobe lift is the amount (measured in
inches or millimeters) that the camshaft is capable of
LIFTING the valve train components in order to open
the valves. The lobe lift is a measure of how much
taller the “egg shaped” portion of the camshaft lobe
is above the base or circular portion of the shaft lobe.
Lift is directly proportional to how far the valves can
open and a worn camshaft (with poor lobe lift) cannot
fully open the valves. The lobe lift therefore can be
directly responsible for proper or poor engine perfor-
mance.
Lobe lift can be measured in 2 ways, depending
on what tools are available and whether or not the
camshaft has been removed from the engine. A dial
gauge can be used to measure the lift with the
camshaft installed, while a micrometer is normally
only used once the shaft has been removed from the
engine.
10 Rocker arm shaft
11 Lash ad,uster
12 Rocker arm C
13 Rocker arm six,,
14 Lash adluster
15 Thrust case
16 orng
17 Camshan
:ig. 211 Exploded view of the camshaft mounting-3.51 engine 1923PGD
Rear bank Front bank
7923PGD4 Fig. 212 Camshaft dowel position during in-
stallation-3.51 engine
DIAL GAUGE METHOD
Lobe lift may be checked with the camshaft in-
stalled. In all cases, a dial gauge is positroned some-
where on the valve train (pushrod, lifter, or camshaft
itself) and the camshaft is then turned to measure the
lift.
Check the lift of each lobe in consecutive order
and make a note of the reading.
1. Remove the valve cover for access to the
camshaft.
2. Install a dial indicator so that the actuating
point of the indicator is directly placed on the
camshaft.
*A remote starter can be used to turn the
engine over during the next steps. If a re-
mote starter is not available, remove the
spark plugs in order to relieve engine com-
pression, and turn the engine over using a
large wrench or socket on the crankshaft
damper bolt. BE SURE to only turn the engine
in the normal direction of rotation.
3. Turn the crankshaft over until the tappet is on
the base circle of the camshaft lobe.
4. Zero the dial indicator. Continue to rotate the
crankshaft slowly until the pushrod (or camshaft
lobe) is in the fully raised position.
5. Compare the total lift recorded on the dial indi-
cator with the elevation specification shown in the
Engine Specification chart.
To check the accuracy of the original indicator
reading, continue to rotate the crankshaft until the in-
dicator reads zero. If the lift on any lobe is below
specified wear limits listed, the camshaft and the
valve tappets must be replaced.
6. Install the valve cover(s).
MICROMETER
) See Figure 213
A micrometer may used to measure camshaft lobe
lift, but this is usually only after it has been removed
from the engine. Once the valve cover is removed
I
@
Fig. 213 Camshaff lobe IIR Is measured In

3-54 ENGINEANDENGINEOVERHALJL
from the, access may be possible (though a little
awkward) to measure the camshaft lobes using a mi-
crometer
In any case, two measurements are necessary for
each lobe. Measurement Y or the total LOBE HEIGHT
and measurement X or the total LOBE WIDTH. To
find the lobe lift, you simply subtract X from Y (sub-
tract the width from the height).
Note each measurement, then make your calcula-
tion to determine the lift. Note the final results and re-
peat the process on the remaining camshaft lobes.
Finally, you should compare your results to the spec-
ifications charts and decide if a new camshaft is in
your future.
REMOVAL &INSTALLATION
2.OL and 2.4L Engines
p See Figure 214
*A special oil seal guide tool, 18998285,
and a plug cap socket tool, MD998182, or ex-
act equivalents are needed to complete this
operation.
1. Disconnect the negative battery cable.
2. Raise and safely support the vehicle.
3. Drain the engine oil.
The EPA warns that prolonged contact with
used engine oil may cause a number of skin
disorders, including cancer! You should
make every effort to minimize your exposure
to used engine oil. Protective gloves should
be worn when changing the oil. Wash your
hands and any other exposed skin areas as
soon as possible after exposure to used en-
gine oil. Soap and water, or waterless hand
cleaner should be used.
93153g3
:ig. 214 Exploded view of the balance shaf
assemblies-2.01 and 2.4L enoines
4. Remove the oil filter, oil pressure switch, oil
gauge sending unit, oil filter mounting bracket and
gasket.
5. Remove engine oil pan, oil screen and gas-
ket.
6. Remove the relief plug, gasket, relief spring
and relref plunger.
7. Lower the vehicle.
8. Using the proper equipment, support the
weight of the engine.
9. Remove the front engine mount bracket and
accessory drive belt,
10. Remove the timing belts and sprockets.
11. Using special tool MD998162, remove the
plug cap in the engine front cover.
12. Remove the plug on the side of the engine
block. Insert a Phillips screwdriver with a shank di-
ameter of 0.32 in. (8mm) into the plug hole. This will
hold the silent shaft.
13. Remove the driven gear bolt that secures the
oil pump driven gear to the silent shaft.
14. Remove and tag the front cover mounting
bolts. Note the lengths of the mounting bolts as they
are removed for proper installation.
15. Remove the front case cover and oil pump
assembly. If necessary, the silent shaft can come out
with the cover assembly.
16. Remove the silent shaft oil seals, the crank-
shaft oil seal and front case gasket
17. Remove the silent shafts and inspect as fol-
lows:
a. Check the oil holes in the shaft for clog-
ging.
b. Check journals of the shaft for seizure,
damage and contact with bearing. If there is any-
thing wrong with the journal, replace the silent
shaft bearing, silent shaft or front case.
c. Check the silent shaft oil clearance. If the
clearance is beyond the specifications, replace
the silent shaft bearing, silent shaft or front case.
The specifications for oil clearances are as fol-
lows
Right shaft l Front-0.0012-0.0024 in. (0.030.06mml l Rear+0.0008-0.0021 in. (6.02-O 05mm) Left shaft l Front-0.002&0.0036 in. (0.05-0.09mm) l Rear-O.0017-O.0033 in. (0.04-0.08mm) To install: 18. Lubricate the bearing surface of the shaft and
the bearing journals with clean engine oil. Carefully
install the silent shafts to the block.
19. Clean the gasket material from the mating
surface of the cylinder block and the engine front
cover. Install new gasket in place.
20. Install the oil pump drive gear and driven
gear to the front case, lining up the timing marks.
21. Lubricate the gears with clean engine oil. In-
stall the oil pump cover, with new gasket in place and
tighten the mounting bolts to 13 ft. Ibs. (18 Nm).
22. Using proper size driver, install the crankshaft
oil seal into the front engine case.
23. Using the proper size socket wrench, press in
the silent shaft oil seal into the front case.
24. Place pilot tool MD998285 or equivalent,
onto the nose of the crankshaft. Apply clean engine
oil to the outer circumference of the pilot tool.
25. Install the front case onto the engine block
and temporarily tighten the flange bolts (other than
those for tightening the filter bracket). 26. Mount the oil filter bracket with new gasket in
place. Install the 4 bolts with washers and tighten to
16 ft Ibs. (22 Nm).
27. Insert the Phillips screwdriver into the hole
on the side of the engine block.
28. Secure the oil pump driven gear onto the left
silent shaft by tightening the driven gear flange bolt
to 29 ft. Ibs. (40 Nm).
29. Install a new O-ring onto the groove in the
front case. Using special socket tool, install and
tighten the plug cap to 20 ft. Ibs (27 Nm).
30. Install the oil pump relief plunger and spring
into the bore in the oil filter bracket and tighten to 36
ft. Ibs. (50 Nm). Make sure a new gasket is in place.
31. Clean both mating surfaces of the oil pan and
the cylinder block.
32. Apply sealant in the groove in the oil pan
flange, keeping towards the inside of the bolt holes.
The width of the sealant bead applied is to be about
0.16 in. (4mm) wide.
*After applying sealant to the oil pan, do
not exceed 15 minutes before installing the
oil pan.
33. Install the oil pan to the engine and secure
with the retainers. Tighten bolts to 6 ft. Ibs. (8 Nm).
34. Install the oil pressure gauge unit and the oil
pressure switch. Attach the electrical harness con-
nector
35. Install new oil filter and fill engine with clean
engine oil.
36. Install the timing belts and all related items,
*The timing of the oil pump sprocket and
connected silent shaft can be incorrect, even
with the timing mark aligned. Make certain
that all special timing belt installation proce-
dures are followed to ensure proper orienta-
tion of the silent shafts.
37. Install any remaining components removed
during disassembly.
38. Connect the negative battery cable and start
the engine.
39. Check for proper timing and inspect for leaks.
REMOVAL &INSTALLATION
p See Figure 215
1. Disconnect the negative battery cable.
2. Remove the transaxle from the vehicle, as
outlined in Section 7.
3. Remove the flywheel/driveplate assembly.
4. Remove the rear engine plate and the bell-
housing cover.
5. If the crankshaft rear oil seal case is leaking,
remove it. Otherwise, just remove the oil seal. Some
engines have a separator that should also be re-
moved.
To install: 6. Lubricate the inner diameter of the new seal
with clean engine oil.
7. Install the oil seal in the crankshaft rear oil
seal case using tool MD998376 or equivalent. Press
the seal all the way in without tilting it. Force the oil
separator into the oil seal case so the oil hole in the
separator is downward.

ENGINEANDENGINEOVERHAUL 3-55
8. Run a bead of sealer along any seams be-
tween the seal case and block. Install the seal case
with a new gasket.
9. Install the flywheel/driveplate and transaxle.
10. Connect the negative battery cable and check
for leaks.
11. Adjust oil level as necessary.
REMOVAL &INSTALLATION To lnstell:
7. Coat the threads of the driveplate/flywheel re-
taining bolts with thread locking compound.
8. Position the driveplatelflywheel on the crank-
shaft flange.
9. On automatic transaxle equipped models, in-
stall the driveplate adapter.
10. Install and tighten the bolts, in a alternating
star pattern, to the following specifications:
l 1.5L engine: 98 ft. Ibs. (135 Nm) l 1.6L, 2.01 and 2.4L engines: 94-101 ft.
Ibs. (130-140 Nm)
al drive plate and rear b See Figure 215
1. Disconnect the negative battery cable.
2. Remove the transaxle, as outlined in Section
7,
3. If equipped with a manual transaxle, remove
the clutch disc and pressure plate. Refer to Section 7.
4. Mark the position of the flywheel/driveplate
on the crankshaft and remove the retaining bolts.
5. On automatic transaxle equipped models, re-
move the driveplate adapter.
6. Remove the flywheel/driveplate from the en-
gine.
l 1.81 engine: 72 ft. Ibs. (100 Nm) l 3.OL and 3.5L engines: 53-56 ft. Ibs.
(72-76 Nm)
11. If equipped with a manual transaxle, install
the clutch and pressure plate.
12. Install the transaxle. Refer to Section 7.
13. Connect the negative battery cable.
healthy supply of penetrating oil and rags is
highly recommended.
Your vehicle must be raised and supported safely to the back of the vehicle. On dual exhaust systems,
remember to insoect both sides of the vehicle. Check
the complete exhaust system for open seams, holes
loose connections, or other deterioration which could + See Figures 216 thru 222
*Safety glasses should be worn at all times
when working on or near the exhaust system.
Older exhaust systems will almost always be
covered with loose rust particles which will
shower you when disturbed. These particles
are more than a nuisance and could injure
your eye. to inspect the exhaust system properly. Placing 4
safety stands under the vehicle for support should
provide enough room for you to slide under the vehi-
cle and inspect the system completely. Start the in-
spection at the exhaust manifold or turbocharger pipe
where the header pipe is attached and work your way
DO NOT perform exhaust repairs or inspec-
tion wtth the engine or exhaust hot. Allow thr
system to cool completely before attempting
any work. Exhaust systems are noted for
sharp edges, flaking metal and rusted bolts.
Gloves and eye protection are required. A
m3p73 Fig. 216 Cracks in the muffler are a guar-
anteed leak Fig 217 Check the muffler for rotted spot
Fig. 219 Cheek for overstretched or torn ex-
welds and seams
haust hangers
fm3p77 Fig. 216 Make sure the exhaust components
are not contacting the body or suspension
lcca3P78

3-56 ENGINEANDENGINEOVERHAUL
,
F C
F
t
. Fig.
220 Example of a badly deteriorated ex- 1 Fig. 221 inspect flanges for gaskets that
haust pipe have deteriorated and need replacement Fig. 222 Some systems, like this one, use
)ermit exhaust fumes to seep into the passenger
:ompartment. Inspect all mounting brackets and
bangers for deterioration, some models may have
ubber O-rings that can be overstretched and non-
supportive. These components will need to be re-
Ilaced if found. It has always been a practice to use a
)ointed tool to poke up into the exhaist system
vhere the deterioration spots are to see whether or
d they crumble. Some models may have heat shield
:overing certain parts of the exhaust system , it will
te necessary to remove these shields to have the ex-
laust visible for inspection also. Before removing any component of the exhaust
system, ALWAYS squirt a Liquid rust dissolving agent
onto the fasteners for ease of removal. A lot of
knuckle skin will be saved by following this rule. It
may even be wise to spray the fasteners and allow
them to sit overniqht.
Flange Type
b See Figure 224 tractor, which oflen means removal of the manifold it
self. Next, disconnect the component from the
mounting; slight twisting and turning may be re-
quired to remove the component completely from thr
vehicle. You may need to tap on the component with
a rubber mallet to loosen it. If all else fails, use a
hacksaw to sep; arate the parts. An oxy-acetylene cut-
ting torch may I 3e faster but the sparks are OANGER-
OUS near the fuel tank, ant 1 at the very least, acci-
dents could happen, result ing in damage to the
under-car parts, not to mei ition yourself.
3EPLACEMEMT
1 See Figure 223
There are basically two types of exhaust systems.
)ne is the flange type where the component ends are
attached with bolts and a gasket in-between. The
)ther exhaust system is the slip joint type. These
:omponents slip into one another using clamps to
iold them together. Do NOT perform exhaust repairs or inspec-
tion with the engine or exhaust hot. Allow the
system to cool completely before attempting
any work. Exhaust systems are noted for
sharp edges, flaking metal and rusted bolts.
Gloves and eye protection are required. A
healthy supply of penetrating oil and
rags is
highly recommended. Never spray liquid rust
dissolving agent onto a hot exhaust compo-
nent. Slip Joint Type
V See Figure 225
Before removing any component on the slip joint
type exhaust system, ALWAYS squirt a liquid rust
dissolving agent onto the fasteners for ease of re-
moval. Start by unbolting the exhaust piece at both
ends (if required). When unbolting the headpipe fron
the manifold, make sure that the bolts are free before
trying to remove them. if you snap a stud in the ex-
haust manifold. the stud will have to be removed wit1
Before removing any component on a flange type
system, ALWAYS squirt a liquid rust dissolving agent a bolt extractor, which often means removal of the
._ manifold itself. Next. remove the mountina U-bolts
liiow the exhaust system to cool sufficiently
Iefore spraying a solvent exhaust fasteners.
Some solvents are highly flammable and
:ould ignite when sprayed on hot exhauti
:omponents. onto the fasteners for ease of removal. Start by un-
bolting the exhaust piece at both ends (if required).
When unbolting the headpipe from the manifold,
make sure that the bolts are free before trying to re-
move them. if you snap a stud in the exhaust mani-
fold, the stud will have to be removed with a bolt ex-
ka3p70 Fig. 223 Nuts and bolts will be extremely
difflcuit to remove when deteriorated with
rust Fig. 224 Example of a flange type exhaust
system joint from around the exhaust pipe you are ext&ting from
the vehicle. Don’t be surprised if the U-bolts break
while removing the nuts. Loosen the exhaust pipe
from any mounting brackets retaining it to the floor
pan and separate the components.
Fig. 225 Example of a common slip joini
type system

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.

3-58 ENGINEANDENGINEOVERHAUL '
*The editors at Chilton feel that most engine
machining should be performed by a profes-
sional machine shop. Don’t think of it as
wasting money, rather, as an assurance that
the job has been done right the first time.
There are many expensive and specialized
tools required to perform such tasks as bor-
ing and honing an engine block or having a
valve job done on a cylinder head. Even in-
specting the parts requires expensive mi-
crometers and gauges to properly measure
wear and clearances. Also, a machine shop
can deliver to you clean, and ready to as-
semble parts, saving you time and aggrava-
tion. Your maximum savings will come from
performing the removal, disassembly, as-
sembly and installation of the engine and
purchasing or renting only the tools required
to perform the above tasks. Depending on
the particular circumstances, you may save
40 to 60 percent of the cost doing these your-
self.
A complete rebuild or overhaul of an engine in-
volves replacing all of the moving parts (pistons,
rods, crankshaft, camshaft, etc.) with new ones and
machining the non-moving wearing surfaces of the
block and heads. Unfortunately, this may not be cost
effective. For instance, your crankshaft may have
been damaged or worn, but it can be machined un-
dersize for a minimal fee.
So, as you can see, you can replace everything in-
side the engine, but, it is wiser to replace only those
parts which are really needed, and, if possible, repair
the more expensive ones. Later in this section, we
will break the engine down into its two main compo-
nents: the cylinder head and the engine block. We
will discuss each component, and the recommended
parts to replace during a rebuild on each. spect the component, buy the necessary parts and OVERHAULTIPS
deliver these to a shop for actual machine work.
Much of the assembly work (crankshaft, bearings, Aluminum has become extremely popular for use
piston rods, and other components) is well within the in engines, due to its low weight. Observe the follow-
scope of the do-it-yourself mechanic’s tools and abil- ing precautions when handling aluminum parts:
ities. You will have to decide for yourself the depth of
l Never hot tank aluminum parts (the caustic hot
involvement you desire in an engine repair or rebuild. 6nk solution will eat the aluminum.
l Remove all aluminum parts (identification tag,
TOOLS etc.) from engine parts prior to the tanking.
l Always coat threads lightly with engine oil or
The tools required for an engine overhaul or parts
anti-seize compounds before installation, to prevent
replacement will depend on the depth of your in-
seizure.
volvement. With a few exceptions, they will be the
l Never overtighten bolts or spark plugs espe-
tools found in a mechanic’s tool kit (see Section 1 of
this manual). More in-depth work will require some cially in aluminum threads.
When assembling the engine, any parts that will
or all of the following:
be exposed to frictional contact must be prelubed to
l A dial indicator (reading in thousandths)
provide lubrication at initial start-up. Any product
mounted on a universal base
specifically formulated for this purpose can be used,
l Micrometers and telescope gauges
* Jaw and screw-type pullers but engine oil is not recommended as a prelube in
most cases.
‘ Scraper
When semi-permanent (locked, but removable) in-
l Valve spring compressor
stallation of bolts or nuts is desired, threads should l Ring groove cleaner l Piston ring expander and compressor be cleaned and coated with Loctite@ or another simi- l Ridge reamer , lar, commercial non-hardening sealant. l Cylinder hone or glaze breaker l Plastigage@ l Engine stand
The use of most of these tools is illustrated in
this section. Many can be rented for a one-time use
from a local parts jobber or tool supply house spe-
cializing in automotive work.
Occasionally, the use of special tools is called for.
See the information on Special Tools and the Safety
Notice in the front of this book before substituting
another tool. CLEANING
) See Figures 227, 228, 229, 230, and 231
Before the engine and its components are in-
spected, they must be thoroughly cleaned. You will
need to remove anv enaine varnish, oil sludoe and/or
c arbon deposits from ail of the componentsio insure
a In accurate inspection. A crack in the engine block or
c :ylinder head can easily become overlooked if hidden
t ry a layer of sludge or carbon.
Most engine overhaul procedures are fairly stan-
dard. In addition to specific parts replacement proce-
dures and specifications for your individual engine,
this section is also a guide to acceptable rebuilding
procedures. Examples of standard rebuilding practice
are given and should be used along with specific de-
tails concerning your particular engine.
Competent and accurate machine shop services
will ensure maximum performance, reliability and en-
gine life. In most instances it is more profitable for
the do-it-yourself mechanic to remove, clean and in- Fig. 227 Thoroughly clean the gasket sur-
faces of the cylinder head as well as . . .
Fig. 229 Use a ring expander tool to remove
the piston rings
fccs3911 ::“,z s,rpuse,a piece of fn old ring to 1
clean the grooves Be careful the ring can
230 Clean the piston ring grooves us-
ing a ring groove cleaner tool, or . . .

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