Re: Misting air-con Quattro V8

[Deric Schare <deric@discoverbrokerage.com>]

Alex Gray-OUPC wrote:
> 
> Please, please, does anyone know how to cure occasional but serious steaming
> up of Quattro 200 and V8 interior. I'm not talking about the usual little
> flush of humidity when an a/c starts up, but a real pumping of humid air
> into the vehicle. A little background...
> 
> I used to have a 200 Quattro with only one fault - the air con. It needed
> recharging about every 6 months - I could live with that, but it had another
> real problem. Every now and again, sometimes ebery day, it would suddenly
> decide to give me a sauna. The windows would mist uncontrollably, and it was
> a misery, especially in winter. It happens a bit more when the weather is
> cold or wet, but can even happen on a fine sunny day.
> 
> I never could work out where the water was coming from - the coolant didn't
> drop much, and I had the plenum and drains etc all checked out for blockages
> and so on. Never did solve it, and one day when the compressor packed up
> (seized so hard it stalled the engine), I decided to sell it as have no
> air-con, and bought a V8 Quattro to replace it.
> 
> Big mistake - the V8 is auto, and despite being 4.2, isn't as fast off the
> mark as the 2.2 Turbo 200, takes 50% more gas, and, horro of horrors....
> turns out to have *exactly* the same aircon problem.
> 
> My wife nearly strangled me the first time it happened - I 'sold' the new
> buy to the whole family on the strength of getting rid of the dreaded
> steaming up, and here we are back at first base!
> 
> It seems to be whenever the vehicle decides a little heating is called for,
> and my first assumption with the first vehicle was that the heater matrix
> was leaking, but the coolant doesn't go down, and I've had it all inspected
> more than once.
> 
> Any ideas would be very gratefully received.
> 
> Alex Gray
> 
> PS the climate control seems to be a real black spot in Audio 100/200/V8
> design. I have had 4 (some people never learn!) and they have all given real
> problems with the aircon. My wife has had two little Hondas with aircon 3
> times as powerful as the Audi's and never a fault!


I went through the same problem with my V8 back in november.I had just
moved from a warm climate(Florida)to a cold climate(Utah).I never had a
problem with the windows fogging in Florida but in a winter climate,even
on max defrost it would get worse.Some cars ventilation systems give the
driver a choice between recirculated air or outside air.I think your
problem is the programer,under the dash, is not allowing any fresh air
in thus recirculating humid cabin air.I fixed the problem by
disconnecting the vacuum line to flapper valve in the passenger foot
well.I've left the valve open allowing outside air in.
It takes a few minutes longer to heat or cool the cabin but no more FOG.