The Washington times., 1928-12-26

. 1TaCIlCa1 examples VIII eApld4A
the rule.
D 1t is possible, for instance, t.
take a couple OF dead spark plug:
from an engine and install brand
new ones, perfect in every respect
, and still have the power plan
skip, buck and gallop as 1t die
before.
In searching for a piston slap ar
owner took his car to a reliable
.shop. 1t was shown that the cyl
inders were scored and that this
would cause the trouble In question
! The cylinders were, accordingly, re
bored, yet when the owner came tc
fAget his machine the same piston
slap greeted him. He accused the
repairers of not doing the work
properly, not knowing That there
are very often two causes resulting
in exactly the same sort of trouble
Worn Cylinders
Pistons working up and down in
worn cylinders will produce slap,
but merely eliminating this one
ecause is no assurance of freedom
from the annoyance. There may
be another cause. With the car in
question it was found, upon closer
examination, that one of the con-
Meeting rods was out of line. 1t
had been bent at the time the
cylinders were scored. and though
it served to contributes its share
toward the annoyance of the piston
slap the double trouble was no more
noticeable than If there had been
but one cause.
When car owner appreciates
the dual nature of car troubles he
is likely to take 1t for granted that
his car will run as it should just
because some trouble has been
found upon its trip to the shop.
= 1t is singular that a car will
often drive no worse with several
things the matter with it than it
would We're only one part giving
trouble. In the case OF an over.
heated engine. for instance. carbu-
retion is greatly disturbed and
valves win stick, yet the car may
run no worse than 1t would IL car
buretor or valves alone troubled it..
When torubles produce the same
DresuIts it seems to make no ma
! terial difference how many causes
there are, which is the same as
saying that removing one cause is
no assurance that the car will run
better. There may be less wrong
with it, but it's a little like drown
ing. Seven feet Of water are just
as fatal to the man who can't
swim as 100.
Clues to Troubles
"A point to watch when the car
ls being repaired is the condition
of any wornout part removed from
! the engine or chassis. The cav
owner is quite likely to look at
a badly pitted valve and conclude
that this was the sole cause OF the
trouble. In his eagerness to in
'sstaIl a new valve and get the car
quent1y fails to consider the pos
sibility of other valve trouble, such
as weak or broken valve spring
means that the final results OF
his work are negative, for he is
just as badly off with one cause
still remaining as he was with two
or three of them.
Any very badly worn part removed
from car ought to be clue TO look
for other causes. If one part Is in
very bad condition it does not follow
that other parts should need replace
ment, but it is warning to examine
all parts which function with that
particular unit. The interrelated
parts are the ones which are likely
y to go bad in pairs or groups; work
] ing together to produce the same re-
suits. they naturally combine to pro-
duce the same troubles when worn,
defective or out of adjustment.
In commenting upon this double
cause trouble, car owner who re.
Gently had an interesting experiment
with it claims that it is often more
expensive to look for one cause than
. to get right down to business and
search for a lot of causes. His en-
gine had undergone some extensive
/. overhauling, but the timing, plugs
and carburetor had not been dis
turbed.
When the repairs were completed
8 a mechanic took the car out for a
test run and found everything run.
/ ming like a clock. you've got the
/ best engine in town." he said. So
! naturally the owner was bit puzzled
when he found the engine bucking
lopelessly before he had driven half
1 way home.
Badly Adjusted
I A hagty inspection revealed the
8fact that a few of the values had
lbeen adjusted for too little clear
lance. They reasoned that when the
sarnechanic tried the car the engine
Twas cold, and that the valves had
Agiven trouble only after heat and
Expansion had developed. which was
kwhen the owner took the wheel.
But the valves properly adjusted
4made no difference. The owner
drought the car back and was
I amazed when the mechanic proved
I beyond all shadow of doubt that
1.-TWO of the spark plugs were dead.
ITO be on the safe side. six new
Iplugs were installed and the carbu-
rotor given a better adjustment.
Still the trouble continued. Next
sift was found that the breaker points
lwere in bad condition. Dressing
5then failed to produce permanent
Hresults. The condenser was taken
off, tested. found to be defective
and replaced. New points were used
\ The engine still skipped!
The owner finally discovered that
his carburetor was leaking air
around the butterfly valve, due to
age and hard use. 1t had to be
gone over. Then the trouble ceased.
In all there We're five causes pro.
ducing so similar a trouble that
even the mechanics failed to dis
= tinguish between them. Any one of
4haan caJ1aas unuld have prOducad