1900 MITSUBISHI DIAMANTE remote start

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

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.