Getting hotter (or getting closer to cold)

[David.Ullrich at ferguson.com]

The air gets "cool" on hot days and pretty cold in the mornings (but not frigid). How can I check the operation of the heater valve? What are your thoughts on that flap seal? I held a lit cigarette near the flap with the AC on, it still sucked the smoke in, so I know some warm air is getting in. How much? No clue. is it enough to cause the AC to be not so cold? Not sure, but I'll soon find out. Any thoughts on the seal? Use an Audi part or any weather seal tape?

Dave

1987.5 Audi Coupe GT "Special Build" 2.3 - Anthracite Black
1998 VW Passat GLS 1.8T - For Sale CHEAP

-----Original Message-----
From: Huw Powell [mailto:human747 at attbi.com]
Sent: Friday, April 19, 2002 11:34 AM
To: David Ullrich - 0018 HQ
Cc: quattro at audifans.com
Subject: Re: Getting hotter (or getting closer to cold)



> OK, I've checked the vacuum system, it's working properly. The flap opens and closes fine. The seal on the flap is pretty much toast and is leaking warm/hot engine compartment air into the system. So that definitely needs to be replaced. So, is there a special Audi part I need or will any old foam weather seal work?

Here's what I don't get - your evaporator is getting toasty cold, the
"recirc" flap closes... why isn't your vent air cold?  Have you tried
cranking the fan up to "4"?  is you heater valve working properly, ie
closing all the way?  (A/C air goes thru the heater core after getting
cooled).

> Also, I wonder if my airbox might be missing some parts. On the outer edge of the airbox is a black sticky seal like substance which makes me think there used to be another part attached there. See http://pictureposter.audiworld.com/10100/airbox1.jpg  to see a pic of this.

That goo held a plastic screen to stop really large debris from clogging
up your fan and heater core.

>  There is also some sort of little sensor on the side of the airbox. It has an electrical connector that goes into a wiring harness that goes into the cabin. See http://pictureposter.audiworld.com/10100/sensor1.jpg  for a pic. What is this sensor? What does it do? is it supposed to just be out in the open exposed to the engine compartment air like that? Any thoughts?

I'm not 100% on this, but I think it is an outside air temp sender, when
the outside air is below some level (40 deg F?) the A/C shuts off
automatically.

That isn't engine compartment air, btw.  There is a seal to the hood at
the top of your firewall, in front of all this junk.  The air coming
into the climate plenum enters through the slits at the back of the
hood.

And last, but not least, there are two A/C related relays in the
fusebox.  I have no idea what either one does, but you might try
swapping in a pair from a car with known working A/C, just in case.

--
Huw Powell

http://www.humanspeakers.com/

http://www.humanthoughts.org/