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#1: VW Maintenance Reality Check

Posted on 2006-07-11 17:49:21 by veeduber

To All:

My son recently purchased a Nissen pick-up fitted with a modest but
thoroughly modern 2.5L inline four cylinder fuel injected engine having
variable valve timing and dual overhead cams actuating 16 valves. On a
900+ mile trip the vehicle averaged better than 25mpg.

As with all new vehicles sold in the States since 1996 the pick-up is
fitted with version 2 of the On-Board Diagnostic system. (ie, OBD-II)
This reflects the fact that like all modern internal combustion
engines, its management is governed by a several embedded
microprocessors, each dedicated to specific tasks. The
electro-mechanical devices controlled by those computers, such as the
fuel injectors and various actuators, as well as the numerous sensors
monitored by the computers, are themselves embedded within the
assembled engine, making manual diagnosis inconvenient if not
impossible. Which is why we have an On-Board Diagnostic system. In
effect, the system uses a computer to monitor itself. Should any part
of the system fail it turns on a warning light and in most cases, falls
back upon a less sophisticated method of control, allowing the vehicle
to run well enough to make it back home.

By periodically interrogating the OBD system and creating an archive of
the results you can see various components slowly degrade over time,
allowing you to schedule their replacement well before any failure can
occur. Of course, to do that you need to be able to connect to the
on-board computer with a PC or lap-top running suitable software, which
is commonly available. Some software facilitates this by linking parts
procurement to the diagnostics, allowing you to place an order by
simply right-clicking the mouse.

All of the information needed to diagnose and repair the vehicle is
contained in the factory service manual, a two-volume set running to
more than 1,600 pages which costs about $250. As with most modern-day
vehicles(*), the pick-up has been designed to reduce the amount of time
needed to swap-out those parts needing periodic replacement. Fasteners
and adjustments have been located so that everything involved in a
particular repair procedure is located within arms-reach of the
mechanic.

------------------------------------------------------------ ------------------------------

By comparison, in the mechanical sense an air cooled Volkswagen is
about as complicated as a two-cell flashlight, with all of the
Preventative Maintenance items clearly spelled out in the Owner's
Manual and/or the Factory Service Manual. But when something finally
wears out -- when repairs are finally needed -- the only diagnostic
computer is the one between the mechanic's ears.

-Bob Hoover

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#2: O/T slightly VW Maintenance Reality Check

Posted on 2006-07-11 19:18:30 by halatos

> By periodically interrogating the OBD system and creating an archive of
> the results you can see various components slowly degrade over time,
> allowing you to schedule their replacement well before any failure can
> occur. Of course, to do that you need to be able to connect to the
> on-board computer with a PC or lap-top running suitable software, which
> is commonly available. Some software facilitates this by linking parts
> procurement to the diagnostics, allowing you to place an order by
> simply right-clicking the mouse.
>

Bob,

This is a project I have been dabbling in for some time with my 1997
Kia. The Davis Instrument "Car Chip E/X" can retreive all four types of
OBD-II diagnostic codes and monitor up to 4 sensors at a time. The nice
part is that the car chip is about the size of a box of matches and can
remain attached to the OBD-II connector, logging data in 5 second
intervals that can be pulled out into a desktop or laptop when it is
convenient, rather than lugging around a laptop for constant
monitoring.

Ideally to get the best results one would start with a new car, take
readings from day one of all the sensors, and repeat as necessary to
see over time what sensors are drifting out of tolerance. The other
thing to consider is the replacement interval that is specified for
things like O2 sensors and MAF sensors, which from what I've researched
are usually spec'd out at 100,000 miles MTBF.

Getting back on topic, I still like driving my VW because of simplicity
and the number of "Point and stare" people you see now that the
aircooled VW is an antique. However, fuel injection, air conditioning,
heat, cruise control and all those other features of 'modern cars' do
make life a hell of a lot more comfortable on a long trip or the daily
commute ;-)

Regards,

Chris

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#3: Re: O/T slightly VW Maintenance Reality Check

Posted on 2006-07-11 22:27:16 by remcow

<a href="mailto:halatos&#64;gmail.com" target="_blank">halatos&#64;gmail.com</a> wrote:
&gt; &gt; By periodically interrogating the OBD system and creating an archive of
&gt; &gt; the results you can see various components slowly degrade over time,
&gt; &gt; allowing you to schedule their replacement well before any failure can
&gt; &gt; occur. Of course, to do that you need to be able to connect to the
&gt; &gt; on-board computer with a PC or lap-top running suitable software, which
&gt; &gt; is commonly available. Some software facilitates this by linking parts
&gt; &gt; procurement to the diagnostics, allowing you to place an order by
&gt; &gt; simply right-clicking the mouse.
&gt; &gt;
&gt;
&gt; Bob,
&gt;
&gt; This is a project I have been dabbling in for some time with my 1997
&gt; Kia. The Davis Instrument &quot;Car Chip E/X&quot; can retreive all four types of
&gt; OBD-II diagnostic codes and monitor up to 4 sensors at a time. The nice
&gt; part is that the car chip is about the size of a box of matches and can
&gt; remain attached to the OBD-II connector, logging data in 5 second
&gt; intervals that can be pulled out into a desktop or laptop when it is
&gt; convenient, rather than lugging around a laptop for constant
&gt; monitoring.
&gt;
&gt; Ideally to get the best results one would start with a new car, take
&gt; readings from day one of all the sensors, and repeat as necessary to
&gt; see over time what sensors are drifting out of tolerance. The other
&gt; thing to consider is the replacement interval that is specified for
&gt; things like O2 sensors and MAF sensors, which from what I've researched
&gt; are usually spec'd out at 100,000 miles MTBF.
&gt;
&gt; Getting back on topic, I still like driving my VW because of simplicity
&gt; and the number of &quot;Point and stare&quot; people you see now that the
&gt; aircooled VW is an antique. However, fuel injection, air conditioning,
&gt; heat, cruise control and all those other features of 'modern cars' do
&gt; make life a hell of a lot more comfortable on a long trip or the daily
&gt; commute ;-)
&gt;
&gt; Regards,
&gt;
&gt; Chris

Yup, that CarChip is a nice tool -- I maintain all my own cars so have
one out of necessity.
It is presently in my in-laws Altima.

Their Altima had been stalling for some reason at random. It would
become hard to start and then drive fine again -- all without rhyme or
reason. It would turn the light on the dash on from time to time.

The Nissan tool (both the actual scan tool and the guy working on that
car - I use the word interchangeable in this discussion) diagnosed the
problem and felt it was necessary to replace the crank sensor, some
secondary o2 sensor and some other sensor. This was in two dealer
visits, neither fixing the intermittent problem -- all because a
particular random code was thrown.

After the third time of visiting the dealership, the manager mentioned
that they'll need a new computer ($1100 + installation). He mentioned
that the ECM must be the cause of all the problems because none of the
stuff they've been replacing makes any sense. He suggested it might be
related to a stopped up AC drain hose. Mind you, he did not suggest
giving them their money back ($900) for the other randomly performed
service.

$1100 is a lot for retirees so they drove it back home, not getting it
serviced.
I just found it hard to believe it was the ECM. After some probing
around with a DVM, found a bad ground connection to the battery and one
to the ECM. Fixed the connections and the car has been running fine
since (but still have the carchip recording stuff, just in case).

So Bob's absolutely right. I like technology, but learned to never
trust it implicitly. There's no better computer than the one between
your ears. Too bad the Nissan tools don't know that..

Remco

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#4: Re: VW Maintenance Reality Check

Posted on 2006-07-12 01:16:11 by Jan

<a href="mailto:veeduber&#64;isp.com" target="_blank">veeduber&#64;isp.com</a> wrote:
&gt; To All:
&gt;
&gt; My son recently purchased a Nissen pick-up fitted with a modest but
&gt; thoroughly modern 2.5L inline four cylinder fuel injected engine having
&gt; variable valve timing and dual overhead cams actuating 16 valves. On a
&gt; 900+ mile trip the vehicle averaged better than 25mpg.
&gt;
&gt; As with all new vehicles sold in the States since 1996 the pick-up is
&gt; fitted with version 2 of the On-Board Diagnostic system. (ie, OBD-II)
&gt; This reflects the fact that like all modern internal combustion
&gt; engines, its management is governed by a several embedded
&gt; microprocessors, each dedicated to specific tasks. The
&gt; electro-mechanical devices controlled by those computers, such as the
&gt; fuel injectors and various actuators, as well as the numerous sensors
&gt; monitored by the computers, are themselves embedded within the
&gt; assembled engine, making manual diagnosis inconvenient if not
&gt; impossible. Which is why we have an On-Board Diagnostic system. In
&gt; effect, the system uses a computer to monitor itself. Should any part
&gt; of the system fail it turns on a warning light and in most cases, falls
&gt; back upon a less sophisticated method of control, allowing the vehicle
&gt; to run well enough to make it back home.
&gt;
&gt; By periodically interrogating the OBD system and creating an archive of
&gt; the results you can see various components slowly degrade over time,
&gt; allowing you to schedule their replacement well before any failure can
&gt; occur. Of course, to do that you need to be able to connect to the
&gt; on-board computer with a PC or lap-top running suitable software, which
&gt; is commonly available. Some software facilitates this by linking parts
&gt; procurement to the diagnostics, allowing you to place an order by
&gt; simply right-clicking the mouse.

&gt; ---snip--


&gt; -Bob Hoover
&gt;


OR, you could buy an affordable (well, cheaper than a good laptop)
generic ODB-II reader tool, which has it's own screen, showing you each
code translated into plain english. Some of them can reset the @check
engine@ light too, timer (mileage) triggered or fault triggered. One
tool works on most cars, US and imported. Snap On makes one, for example.

Run diagnostics and reset those pesky check engine lights on your
relatives' and neighbors' cars, and if you charge 20 bucks each time,
the device will pay itself back.

Or take your car to a shop and have the codes read and maybe printed out
for you. They might not like doing it if it's the only thing you ask
(for them to do free of charge or for pennies), so include that in your
regular oil changes and other maintenance visits to the shop... IF you
are the kind of person who takes the car to a shop for a simple oil
change... &lt;grin&gt;

Jan

--
--------------------------------
Beer is made by fermentation caused by bacteria feeding on yeast cells
and then defecating.
In other words, it's a nice tall glass of bacteria doo-doo.

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#5: Re: VW Maintenance Reality Check

Posted on 2006-07-12 02:57:41 by veeduber

Jan wrote:

&gt; OR, you could buy an affordable (well, cheaper than a good laptop)
&gt; generic ODB-II reader tool, which has it's own screen, showing you each
&gt; code translated into plain english.
------------------------------------------------------------ --------------------

The problem here is that a simple reader does allow the creation of an
archive of data, it simply reports the current state of the system.
This worked well enough with OBD-1 but as the number of on-board
computers increased and the systems became more complex, a growing
percentage of the reported faults are erroneous, reflecting
intermittant errors within the reporting system itself rather than real
problems associated with any of the vehicle's components.

Computers offer a nice example of this, in that as they became more
complex a higher percentage of errors was seen in the interconnections
between the components. (I still have a working S-100 system out in
the shop :-) This lead to the development of multi-layer circuit
boards and a significant reduction in the number of connections. We
are starting to see the same thing in On-Board Diagnostic systems, in
that many apparent errors are turning out to be electrical glitches in
circuits common to all of the components, such as the power or
grounding circuits.

While some people find the thought of doing their own computerized
diagnostics difficult to accept, the fact is that even when a dealer is
honest their mechanics still perform a fairly high percentage of
unnecessary 'repairs.' The only way to protect yourself is to become
fully versed in the system because, computerized or not, YOU are still
the Mechanic-in-Charge of your vehicle.

-Bob Hoover

PS - someone wrote to ask the purpose of the (*) in my original
message. It had to do with the fact that while most modern vehicles
were designed with a view toward ease of maintainenance, the New Beetle
was not among them. Dropping a much-modified copy of the Concept 1
body onto a Golf chassis was purely a sales ploy, degrading the
maintainability of a proven chassis and leading to a number of required
recalls and repairs.

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#6: Re: VW Maintenance Reality Check

Posted on 2006-07-12 17:47:50 by halatos

&gt; OR, you could buy an affordable (well, cheaper than a good laptop)
&gt; generic ODB-II reader tool, which has it's own screen, showing you each
&gt; code translated into plain english. Some of them can reset the @check
&gt; engine@ light too, timer (mileage) triggered or fault triggered. One
&gt; tool works on most cars, US and imported. Snap On makes one, for example.
&gt;
&gt; Run diagnostics and reset those pesky check engine lights on your
&gt; relatives' and neighbors' cars, and if you charge 20 bucks each time,
&gt; the device will pay itself back.
&gt;

Jan,

I did own one of these &quot;read 'em and reset&quot; type of scanners a while
back, but to be honest they aren't really useful when you have a
persistent problem that has a large number of possible solutions. If
the scanner says &quot;O2 sensor stuck&quot; based on the definition of the
OBD-II code, it may be the O2 sensor, but it may also be the connector,
the wires, or some other sensor upstream that is throwing enough fuel
into the mix to make the computer think the O2 sensor is stuck.

My experience with the aircooled VW has been that 'poor performance'
can be attributed to a fairly large number of things, from timing,
mixture, mechanical problems, dirty air cleaner, and so on. Without a
computer to attempt to tell you what's wrong you have to do some
investigation. People seem to think that &quot;Oh, now that my CEL is on
I'll just get the code and replace the part it says to replace&quot;. That
type of logic will cause you spend money on repairs that are not
necessary. OBD-II codes indicate a problem in a circuit, not
necessarily a sensor. People tend to lose sight of that. Having a
diagnostic code will get you pointed in the right direction -most of
the time-, but it is not the end of the diagnostics that are needed to
accurately repair a problem.

Chris

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#7: Re: VW Maintenance Reality Check

Posted on 2006-07-13 17:25:46 by robrjt

I much prefer the simple, less complicated engine compartments as in my
VW bug, benz 240D and 300SD than my C5 corvette. Love those purely
mechanical engines. I absolutely hate the plastic covers that
encasulate new car engines, as if it is a hands off approach to car
ownership.


<a href="mailto:veeduber&#64;isp.com" target="_blank">veeduber&#64;isp.com</a> wrote:
&gt; To All:
&gt;
&gt; My son recently purchased a Nissen pick-up fitted with a modest but
&gt; thoroughly modern 2.5L inline four cylinder fuel injected engine having
&gt; variable valve timing and dual overhead cams actuating 16 valves. On a
&gt; 900+ mile trip the vehicle averaged better than 25mpg.
&gt;
&gt; As with all new vehicles sold in the States since 1996 the pick-up is
&gt; fitted with version 2 of the On-Board Diagnostic system. (ie, OBD-II)
&gt; This reflects the fact that like all modern internal combustion
&gt; engines, its management is governed by a several embedded
&gt; microprocessors, each dedicated to specific tasks. The
&gt; electro-mechanical devices controlled by those computers, such as the
&gt; fuel injectors and various actuators, as well as the numerous sensors
&gt; monitored by the computers, are themselves embedded within the
&gt; assembled engine, making manual diagnosis inconvenient if not
&gt; impossible. Which is why we have an On-Board Diagnostic system. In
&gt; effect, the system uses a computer to monitor itself. Should any part
&gt; of the system fail it turns on a warning light and in most cases, falls
&gt; back upon a less sophisticated method of control, allowing the vehicle
&gt; to run well enough to make it back home.
&gt;
&gt; By periodically interrogating the OBD system and creating an archive of
&gt; the results you can see various components slowly degrade over time,
&gt; allowing you to schedule their replacement well before any failure can
&gt; occur. Of course, to do that you need to be able to connect to the
&gt; on-board computer with a PC or lap-top running suitable software, which
&gt; is commonly available. Some software facilitates this by linking parts
&gt; procurement to the diagnostics, allowing you to place an order by
&gt; simply right-clicking the mouse.
&gt;
&gt; All of the information needed to diagnose and repair the vehicle is
&gt; contained in the factory service manual, a two-volume set running to
&gt; more than 1,600 pages which costs about $250. As with most modern-day
&gt; vehicles(*), the pick-up has been designed to reduce the amount of time
&gt; needed to swap-out those parts needing periodic replacement. Fasteners
&gt; and adjustments have been located so that everything involved in a
&gt; particular repair procedure is located within arms-reach of the
&gt; mechanic.
&gt;
&gt; ------------------------------------------------------------ ------------------------------
&gt;
&gt; By comparison, in the mechanical sense an air cooled Volkswagen is
&gt; about as complicated as a two-cell flashlight, with all of the
&gt; Preventative Maintenance items clearly spelled out in the Owner's
&gt; Manual and/or the Factory Service Manual. But when something finally
&gt; wears out -- when repairs are finally needed -- the only diagnostic
&gt; computer is the one between the mechanic's ears.
&gt;
&gt; -Bob Hoover

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#8: Re: VW Maintenance Reality Check

Posted on 2006-07-22 21:03:51 by J

&lt;<a href="mailto:veeduber&#64;isp.com" target="_blank">veeduber&#64;isp.com</a>&gt; wrote:

&gt; By comparison, in the mechanical sense an air cooled Volkswagen is
&gt; about as complicated as a two-cell flashlight

Damn, that's discouraging. Guess I'll stick to oil lamps.

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