What's with the extra wipe after turning off the wipers? Why does the paint on my car seem to fade/crack/peel so easily?
What is the purpose of the fuel filler neck recall?
What's with the extra wipe after
turning off the wipers?
Some people consider this an annoyance while others
think it's great. It's a common "feature" on most GM cars. Although some people
claim that their GM car doesn't do it. There are also aftermarket wiper motors
which don't do it. So where did it come from?
The ultimate wiper trivia might trace this back to an
excess inventory of the old kind of intermittent wipers which violated that
original patent. Someone had a patent on the infinite-variations intermittent
wiper style. The 4th gens have little tick marks with about 10 levels of
intermittency. The old kind had an infinite amount of intermittency, rather
than a variable resistor with only fixed values possible. GM was one of the
first companies to settle with the intermittent wiper patent person. But it
also looks like GM changed their method of doing intermittent wipers at about
the same time. As for the "extra wipe", it's just because of the way the RC
circuit was set up. There must have been a little glitch when the switch shut
off, such that a little extra charge got into the RC circuit and pushed it over
the limit right as you turn off the switch. It looks like they fixed this
glitch when they changed the style of intermittent wiper control.
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Why does the paint on
my car seem to fade/crack/peel so easily?
Up through the 1987 model year, F-cars were built at
two different assembly plants. One was Norwood, Ohio and the other was in Van
Nuys, California. The plants both built the two F-cars identically, except with
respect to the paint process.
Since before the 3rd generation F-cars were started
in late 1981, the Van Nuys plant was forced to use a water-based enamel paint
because of the very restrictive CA laws enforced by the CARB (California Air
Resources Board). This water-based paint was very different from the
solvent-based paint used at Norwood. Another difference was the way the paints
were applied. Because it was mostly non-polluting, the water-based paint at Van
Nuys could be sprayed on by a conventional spray-gun technique. There were no
volatile solvents (only water), and whatever paint did not stick to the cars
(over spray) was caught by air filters.
Starting with the 3rd generation models, Norwood
began using a much more sophisticated paint application mechanism called a
Turbo Bell. The Turbo Bells were high speed (30K RPM) turbines that literally
atomized (fogged) the paint so very little solvent was required (much less than
with conventional spraying techniques). The Turbo Bells dispense a cone shaped
fog of electrically charged high-solids enamel. This fog would be up to 55%
solid paint, with volatile organic solvents as the carrier. The charged paint
particles would be attracted to the vehicle body, which was also electrically
charged (with opposite polarity from the paint) so that the paint particles
would attract and stick. Very little over spray would result from this process,
since the high-solids paint fog would be attracted directly on to the vehicle
by the electric charge. The carrier solvent would evaporate, and was drawn into
burning stacks where it would be incinerated.
The Turbo Bell painting technique is now used by
virtually all manufacturers and combined with solvent-borne enamel like that
used at Norwood, results in the highest quality paint jobs. In 1987, Norwood
turned turned out some of the finest quality paint jobs in the world. By
comparison, the water-based paint would be much more dull, thin, and prone to
problems.
The much stricter CARB emissions laws did not allow
the use of solvent borne paint at Van Nuys. That meant that the paint jobs
coming out of Van Nuys could never be as good as those from Norwood. The water
based paint was not as hard, or shiny as the solvent based paint used at
Norwood. Then came some real problems. Due to the ever-tightening CARB
standards, Van Nuys was forced to give up the spray guns and adopt the Turbo
Bell paint application system for the '86 model year. You would think that this
sounds good, but the problem was that the Turbo Bell system was designed for
solvent based paint and not the water-based paint mandated by CARB at Van Nuys.
There was a period where they had not really sorted out how to re-formulate the
water-based paint and primers to work with the Turbo Bells, and this resulted
in many problems especially during the '86 model year. It took several years
for some of the problems to be solved.
You can tell where your vehicle was built by looking
at the 11th digit of the VIN. If it's an "N", then the car was built at
Norwood, if it's an "L", then the car was built at Van Nuys. Another
interesting difference (although there's no concrete evidence) is that cars
which were built at Norwood had the top of the cowl painted over in flat black,
while vehicles built at Van Nuys left this area body colored.
The Norwood plant was closed after the 1987 model
year finished out, as GM had decided that F-car production could only sustain a
single plant, and the Van Nuys plant was the more modern of the two. Also, Van
Nuys was a larger plant, and had only a two level conveyor system rather than
the complicated 5-level system used at Norwood. The more constricted Norwood
plant only turned out about 41 vehicles per hour, while 54 per hour could be
sustained at Van Nuys. Each F-car took about 20 hours to assemble completely
from start to finish. Unfortunately the plant that remained open (Van Nuys) had
the poorer quality paint process due mainly to the mandated use of water- based
enamel. All remaining 3rd generation F-cars from 1988 through 1992 were built
at Van Nuys. All 4th generation F-car production moved to Ste. Therese in
Canada.
It is also believed that paint problems in 1988-1992
models are a result of GM reformulating the primer base which was put on the
cars. The primer was made to better stick to the sheet metal/fiberglass and
better resist rust and corrosion. Unfortunately, it also resisted the paint
from sticking to it - better known as "delamination". Thus, after a number of
years, the paint starts to unadhere from the primer base even to the point
where it will peel off in sheets. GM will cover repainting of vehicles with
such delamination problems, but only up until they're 5 years old. This is why
GM released technical service bulletin #231054 which allows dealerships to
handle such problems on a "case by case basis to give goodwill adjustments to
customers".
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What is the purpose of
the "fuel filler neck" recall?
General Motors has determined that certain 1991-92
Firebird/Camaro model vehicles fail to conform to the requirements of Federal
Motor Vehicle Safety Standard (FMVSS) 301, "Fuel System Integrity." These
vehicles could exhibit cracks or "pin holes" at the fuel filler neck solder
joint. This could result in fuel odor or fuel leakage. If an ignition source
was present, fuel leakage resulting from this condition could result in a
vehicle fire. Contact your dealer about this recall.
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