'91 100q Alternator Belt Screech & 400-500rpm Idle Speed

[jlagnese at massed.net]

What is the belt arrangement? Could the load on the
ac belt loosen the alternator belt? If so, maybe a
slight loosen may be in order.
---- Original message ----

  Date: Wed, 19 Sep 2012 21:21:29 -0400
  From: "mboucher70 hotmail.com"
  <mboucher70 at hotmail.com>
  Subject: Re: '91 100q Alternator Belt Screech &
  400-500rpm Idle Speed
  To: "Fred Munro" <munrof at sympatico.ca>,
  <wadd-wadd at usa.net>, <quattro at audifans.com>
  >Along similar lines, I started experiencing a
  belt screech earlier this >summer. I figured it
  was the A/C belt because it only happened when the
  A/C >was running at the moment when the car went
  from stopped and accelerated to >move off.>>Got
  all ready to tighten the A/C belt, got on the
  garage floor where I could >get to it, and to my
  surprise, the A/C belt was quite tight. The
  alternator >belt was a little slacker than it
  should've been, so I tightened it up and >the
  noise went away.>>Fast forward through a long, hot
  summer of hard driving and pushing this old >beast
  through some record setting temperature days.
  Towards the end of the >summer it started
  squealing again. But only when the A/C is
  on!>>Ever heard of an alternator belt that squeals
  ONLY when the A/C compressor >is running?>>Belts
  look good, have about 10,000 miles on them, and
  were sold & installed >by a shop that only does
  Audi/VW's, so I'm pretty sure they're the correct
  >belts.>>-----Original Message----- >From: Fred
  Munro>Sent: Tuesday, September 18, 2012 8:24
  AM>To: wadd-wadd at usa.net ;
  quattro at audifans.com>Subject: RE: '91 100q
  Alternator Belt Screech & 400-500rpm Idle
  Speed>>There are a few things to check.>Are you
  using a metric V-belt (i.e from the Audi dealer)
  or a SAE belt from>your local FLAPS? Metric
  V-belts use a different numbering system than
  SAE>V-belts and some metric cross-sections cannot
  be matched with SAE belts.>There are
  cross-references available to match up belts, but
  before using a>SAE belt you should check for
  differences in length, cross-section,
  and>ride-out. I had a squealing problem with my
  first Audi ( an '86 5000tq) and>solved it by using
  metric belts from the dealer.>If a V-belt is worn,
  it can get narrow enough that it bottoms out in
  the>pulleys - if the top of the belt sits below
  the outer edge of the alternator>pulley it may be
  worn too much.>Check for wear on the pulleys.
  Pulleys don't last forever and these cars
  are>getting enough hours on them that the pulleys
  may be losing their profile to>wear.>Are all the
  pulleys aligned in the same plane? If one pulley
  is cocked at an>angle (i.e. the alternator mounts
  allow it to twist a bit) the belt will>squeal and
  wear.>>HTH>>Fred Munro>'97 S6>>-----Original
  Message----->From: quattro-bounces at audifans.com
  [mailto:quattro-bounces at audifans.com] On>Behalf Of
  wadd-wadd at usa.net>Sent: Monday, September 17, 2012
  9:37 PM>To: quattro at audifans.com>Subject: '91 100q
  Alternator Belt Screech & 400-500rpm Idle
  Speed>>Two issues with my '91 100q>>-the
  alternator belt lets out an embrassing screech
  every other day>regardless of how much I tighten
  it. Any way to address this? Any special>belt or
  dressing?>-the idle speed is about 400-500rpm. The
  car doesnt stall
  though.>>Thanks!>>_______________________________________________>quattro
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  list>http://www.audifans.com/mailman/listinfo/quattro>http://www.audifans.com/kb/List_information>>_______________________________________________>quattro
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  >>_______________________________________________>quattro
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