central locking ? WHY$

[jkarlsso@metabolex.com (Jonas K.)]

On 5/22/02 7:50 PM, "Captnbr@aol.com" <Captnbr@aol.com> wrote:

> Does anyone know why VW decided to use a system like this?  It just seems
> like it is so complicated and stupid. With all these airpipes and hoses and
> stuff.  Why didn't they they just use simple electrical solenoids type things
> for the locks? 

Up to speculation at this point, but I'd say most likely it was a
reliability/cost issue. The system was designed almost 20 years ago, who
knows how reliable or expensive those electrical solenoids were. Today the
solenoids are not expensive, so they make more sense.

I actually think it's a fairly elegant system. Only when it malfunctions
does anyone complain about it, and apparently most have lasted for at least
15 years. Pretty good for modern automotive standards. Wires, sensors, and
solenoids would be just as complicated in terms of problem diagnosis,
repair, etc. 

> I hate the sound it makes too ugghghhgghghhghghghghghgggploop. Everybody is
> always like "what the F@#k was that noise"?

When operating normally, the pump should be nearly inaudible. It should also
not run as long as your onomatopoeia (look it up) suggests. It should run
only approx. one second.

Go to the pump, and disconnect the air connection. Borrow a vacuum pump with
gauge from someone, or buy one, and pump a vacuum into the line going to all
the solenoids. It should hold vacuum for quite a while, Bentley probably has
a spec. 

The pump shuts off once it senses the proper vacuum/pressure, or after a max
time (like 30 seconds). If there is a leak, then it will take longer to
reach the vacuum/pressure, and the pump will run for a longer time. If the
leak is big enough then the pressure will not be reached, and as a result
the pump will run a long time. Finding the leak is not that difficult.

Also, the pump should be enclosed in a stiff foam casing, to insulate the
sound. If that is gone, then it could be very loud, otherwise the pump is
probably bad, and a replacement would help out lots with the noise.

HTH, 
Jonas