I must say I was quite uncertain about where to place this
article, or better, this sad tale of mine. Finally I decided to put it
in the Battlefield section as it was, in fact, a lost battle.
This story may not be directly related to oil
hydraulics, but is a perfect example of how it's important to use your
OWN head while troubleshooting a failure, instead of blindly
following an "expert's" opinion. Don't get me wrong here, I am not
against the "expert", I am against the "blindly".
Some three years ago I was very happy to
present my wife, who had recently (finally) gotten her drivers license,
with a "brand new" 1995 Peugeuot 306 with a generous 1.8 liter
turbocharged intercoolled diesel engine with mechanical fuel injection,
the feature which alone was more than enough to convince me into buying
the vehicle (the presence of the Bosch piston fuel injecting pump was
filling me with warm feelings...) The car cost 2k eur, which
seemed quite a bargain at the time as the automobile was equipped with
air conditioning, power steering, electric windows, mirrors, central
lock, radio, etc...
For about a week I was delirious with joy at
the car. Then the perfectionist inside took over and the nightmare
started... Yes, yes, I am one of those unfortunate guys who seek
explanation to anything around them that is not yet explained, and are
unexplainably compelled to make everything work "the way it is
supposed to". Like when my new Vista armed computer (few days after
the infamous Vista launch and crash) went gu-gu and refused to accept
USB memory pens by freezing whenever a memory pen was inserted, it
became impossible for me to work even when I was not using any pen. The
itching feeling of incomplete functionality was there... driving
me crazy, demanding fixing and causing my Microsoft Gates related
vocabulary to expand every day...
Anyway, the machine was running perfect except
for the fact that every now and then the motor seemed to loose power,
like when I would accelerate, the acceleration rate would be kind of
jerky, sometimes the car would just leap forward like a muscle car, and
sometimes it would feel like I wasn't accelerating at all, although I
was pedaling to the floor. Another symptom was the inability to
maintain steady speed while cruising, there were always small, almost
imperceptible jerks present. My foot wouldn't change the position and
yet I could feel the car to accelerate and decelerate on its own. My
wife didn't see it as a problem, and indeed it was almost not
noticeable, but the problem WAS there and it was demanding, no, CRYING
FOR a solution. All the joy of driving had been sadly gone...
Confident it was fuel related problem I went
to my car mechanic to see if he could take a look. Unfortunately my
good friend had left for Angola and I dealt with an employee of his,
who inspired confidence with many years of experience and lots of Grey
hair... As soon as I related the problem he said: Don't you worry, my
good sir, it's the injector pump problem, we will repair it and it's
gonna be all right! A week later I went to the shop to pick up the car.
"Does it run smooth?" - I asked - "Like a missile" - said the
mechanics. The bill showed that the car, besides the injection pump
repair also got new fuel and air filter, which seemed logical, so I
went home happy. First miles, however, showed that "the missile" kept
on missiling in the same jerky manner it had done before. Pretty sad I
called the shop and arranged for another visit.
"Don't you worry, we'll replace
the injection pump, the one you have is, unfortunately, damaged beyond
repair." - said the mechanic. Although the price of the new
injector pump was a little high, It was a matter of principle for me,
so I gave it a go. A week later I went to the shop to pick up the car.
"Does it run smooth?" - I asked - "Like a jet fighter" - said the
mechanics. A quick glance under the hood revealed a "new used" Lucas
injector. The bill showed, besides the fuel injection pump, an original
intercooler air duct. "Just in case" - explained "the artist", so I
went home happy. First miles, however, showed that the "jet fighter"
was jetting in the same freakin' jerky way. Pissed off, I called the
shop and arranged for another visit.
"Looks like we've got ourselves a tuff one
here" - said the mechanic - "don't you worry, we'll replace the turbo
charger, and it's gonna be all right!" When I asked why the turbo, the
answer was "well, there's not much left to replace, is there? It's got to be
the turbo" Then I told him I had actually measured the air pressure
inside the intercooler and it was not too different of what was
considered normal, in fact, I asked him the correct pressure value,
which he didn't know, and I am guessing, considered the question as an
offence to his experienced self. "Anyway", he said, it's not a "normal"
turbo, but a "volumetric" one, which is far more complicated and prone
to malfunction". My wife, who had been presented with the car and
hadn't driven it yet was beginning to worry, so I gave the new turbo a
go. A week later I went to the shop to pick up the car. "Does it run
smooth?" - asked I. "You wouldn't beleive it!" - said the mechanic -
"like a rocket it does!!!" The bill showed the turbo charger and tons
of labour, and some other shit I can't remeber. Well, it's life,
thought I, and went home happy. First miles, however, proved that
rocket science has a lot to achieve yet, as the "rocket" was rocketing
in THE SAME F@CKING JERKY WAY as before. I didn't call the shop any
more, I decided to pay a surprize visit one of the next days.
Next time I showed myself in the workshop I
could swear I heard the sound of a breaking glass and a person running
away. I guess my facial expression and clenched hands had given me
away... Or maybe the blood filled eyes... Anyhow, the artist
wasn't present, but there was an assistant of his, changing oil to some
car, and he asked me what the matter was. Frustrated, I shared
with him my story, which surprised him a lot. Well, he said, I am no
mechanic, but I do think it's fuel related, and the most probable
explanation for the not linear fuel delivery would be air bubbles
inside the fuel line. You see, he kept on, on this car there's no
auxiliary pump inside the fuel tank, so the injector pump creates
depression inside the suction line and if you have even the smallest
opening to the atmosphere along the fuel line, air gets sucked in, air
bubbles are formed, and there you go - the jerky engine work,
especially on high regimes during acceleration. Besides the most
probable cause, it's also the easiest to confirm, all you need to do is
install a transparent piece of hose in the admission line of the fuel
pump and check for air bubbles. But since you're here, lets take a look
at the fuel filter assembly, as it's the part that gets tampered with
the most. Stumbled, I didn't utter a word and watched the man open the
filter. It turned out that underneath the filter, in the bottom of the
assembly, there was a small plug (water draining?) which had a
suspiciously dry and dead stiff o'ring seal. After 2 minutes spent
replacing the o'ring and closing the filter the problem was gone...
GONE for good!!! For the first time in my life I felt like
kissing another man. (please don't use this phrase out of the context)
Then came the feeling of enormous shame. I,
more then anyone, should have thought about air entering the suction
line of a pump. I am the one who has used transparent hoses for air
detection. I am the one who has always defended independent
troubleshooting. I am tired of seeing oil leaks or air entering
hydraulic systems through faulty o'ring seals... The list goes on...
My brain just got frozen completely by the
fact that I was dealing with the area beyond my expertise, so I
completely surrendered myself to an opinion without questioning it. I
have absolutely no excuse and the whole expense I suffered (doubling
the initial price of the car) served me a lesson to be never forgotten.
The point here is that even the most experienced
experts mistake. Don't be afraid to ask questions when you see
something you don't understand, there's no shame in it. Whenever in a
troubleshooting situation, look for educating yourself about the
subject. Don't surrender yourself to an expert's opinion BLINDLY, seek
for logical explanation or ask him for one. In my example my dumbness
and mind's inertia cost me two times the initial price of a used car.
In case of a hydraulics machine, an incorrect or illogical
troubleshooting technique may easily cost as much as several NEW cars
and tons of labor. Make your own conclusions. As for me, I find my
inner piece considering this predicament as a piece of education I paid
P.S. No need to say that my Vista expanded Microsoft related vocabulary
was used by me ON me for at least a month after the o'ring change.