[s-cars] Re: squeaky hamster wheel in dash

[Robert Pastore]

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The job isn't as bad as Bentley makes it sound.  You do not need to remove
the entire HVAC box at the firewall.  Instead, you can just remove the two
straps that hold it down, and slide back the big boot that connects to the
evaporator.   Then, with a little coaxing, you can separate the housing
enough to get the fan out through the boot hole  without removing the entire
HVAC unit.   (Note to MYERS: I said the boot hole, not the butt hole!)

Be sure to clean the HVAC drain line while you are in there.  A clogged
drain will cause h20 to back up, spray you with a cold shower on humid days,
and contribute to ruining the bearings on the new fan too.

rgds,
Bob

-----Original Message-----
From: Franco Barber [mailto:feb at febsun.cmhnet.org]
Sent: Wednesday, August 06, 2003 9:49 AM
To: William Noland
Cc: s-car-list at audifans.com; dburig at igsenergy.com; bullitt at gwi.net
Subject: Re: [s-cars] Re: squeaky hamster wheel in dash


Hello,

I also have the annoying squeak.  Mine's on a 95 A6, but it's the
same hvac mechanism as the S6. (Don't know about the S4?)

High-pitched ear jarring squeak. I've had it about two years.
It only comes on after the car has been driving for 20-30 minutes
or so AND then I hit rough pavement.

If I turn the climate control off, wait a minute, and then back on
the noise will go away (for a while.)

By the time the noise comes on the car has been running 25 minutes,
the inside temp has stabilized, and so the fan is at a low rpm.
I have found that, when the noise begins to appear, if I increase
the fan speed to a higher level the noise goes away.
How high? I have to play it by ear.    Sometimes 80-90% of full scale.
Then over the course of the next few minutes I can slowly decrease
the fan speed and usually the noise will not come back.

I too thought that this was the small fan that draws air past the
sensor.  I thought this because (a) the noise seemed too high pitched
to be the main ventilator fan, since I imagined that the main fan was
large and turned at relatively low RPMs, and (b) the noise seemed
constant to me, and did not seem to vary with the fan speed setting.

I went so far as to disassemble my dash to get at the small fan
that draws air.  It ran fine for hours on the test bench with all
the vibrations I could throw at it.  When I re-assembled it, I inserted
a kill-switch inline with the small fan so I could cut the current to
it on demand.   I fished the switch over into the glove box.

So, the next day I was out driving and here comes the squeak!
I pull over to a safe place.  Don't dare to stop the engine
as this will stop the squeak.  Open the glove box and kill the
small fan.  The squeak ..... stayed!  Still squeaking away loud
as ever with the small fan disconnected.

So, at least in my case, it's not the small fan, much as I would
have liked to believe that it was the case.

It's probably the main ventilation fan's bearings.
They're weak, and after they get hot it takes a small bump to
knock the fan off balance, and the bearings can't stop it.
It's curious that it can be 'healed' by running it at higher RPMs
for a while.  Maybe this helps stabilize it and the gyroscope effect
keeps it from getting off balance again?

Dealer has quoted something like $450 to replace the blower,
including labor.   I know there are links out there to web
pages that show you how to do this job but I'm not up to it myself.
It's been driving me crazy two years and I'm about ready to have
the dealer fix it.

Franco

(kill switch is still there.  got to remember to take it out soon.)

On Wed, Aug 06, 2003 at 05:47:45AM -0700, William Noland wrote:
> Sounds like a case of squeaky climate control fan. This is a small fan
> that draws inside air through the tiny vent in the middle of the dash to
> the climate control unit, so that it can measure and regulate the
> cockpit temperature. You might try placing a spare finger over the vent
> next time it happens and see if the sound level varies. If you search
> the archives, I believe you can find details on replacing the unit. In
> my case, the hamster finally got over whatever was (occasionally) ailing
> him and the fan has been quiet for quite some time. Believe others
> experienced the same pattern.
>
> Makes me wonder if some small bit of dirt or moisture gets through the
> vent into the fan and starts it a-squeaking. Said dirt/moisture
> eventually goes away and all is quiet again? You might want to adopt a
> wait-and-see attitude on this one.
>
> Bill Noland
> enjoying the peace and quiet
>
> >It comes and goes, but my car has developed an occasional squeak/squeal
> >that
> >sounds as if it is coming from behind the climate control head/radio area
> >if
> >the dash.  Best described as the sound a squeaky hamster exercise wheel
> >would make.  (Unlike Paul K=92s TR3, I=92m fairly sure no rodents reside
> >in=
> >my
> >vehicle.)  Everything seems to be fully operational.  First noticed this
> >three weeks ago on a long trip, when it was fairly persistent, but
> >haven=92t
> >heard it except for a few seconds at a time intermittently in the last
> >week.
> >Any ideas what this is?  Blower motor bearings going bad?  Source for
new?
> >Approximate tithe to Audi Gods?
> >
>
>
> _______________________________________________
> S-CAR-List mailing list
> S-CAR-List at audifans.com
> http://www.audifans.com/mailman/listinfo/s-car-list
>

--
Franco Barber                   feb at febsun.cmhnet.org
95 A6Q w/Gamma CD mit RDS!      Columbus, Ohio  USA
95 A6Q 5spd w/HCB-30 bluetooth car kit!
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