[V6-12v] V6-12v Digest, Vol 72, Issue 3

[Tom Leppke-Hennig]

>
> Message: 4
> Date: Wed, 28 Apr 2010 14:25:58 -0400
> From: Kent McLean <kentmclean at comcast.net>
> Subject: Re: [V6-12v] FW: Window Fogging
> To: v6-12v at audifans.com
> Message-ID: <4BD87DB6.70502 at comcast.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Casimiro Izquierdo wrote:
>>
>> ----Forwarded Message----
>> From: caig01 at yahoo.com
>> To: caig01 at yahoo.com
>> Sent: Wed Apr 28th, 2010 1:41 PM EDT
>> Subject: Window Fogging
>>
>> I am having a problem with my 1995 Audi 90S.  When the car warms up
>> there is
>> a cloud of "water vapour" that rises tthough the vents and fogs the
>> windshield and the driver side window.  This "vapour cloud" leaves a
>> film on
>> the glass surface that is very difficult to clean; it smears and Windex
>> clears it to some extent.  It does not seem to be burning oil, which the
>> car, but it seems to be coolant.  It does not smell much like coolant,
>> but
>> the film suggests antifreeze deposit.
>>
>> - What can be done to either prevent this from happening?
>> - How can I completely close the vents?  I do not care about A/C or
>> heating,
>> neither work.
>>
>> Any suggestions will be appreciated.
>
> It sounds like the heater core is leaking. That fog on the windshield
> is probably from the coolant drying on the it.
>
> If you truly do not need the heat, you can bypass the leaking core.
> There are two heater hoses (about 3/4" or 2cm or so) going from the
> engine through the fire wall to the heater core. Follow those two
> hoses back to the source on the engine block, remove them, and replace
> them with a shorter (1 foot or 30cm or so) piece of heater hose, in
> a U-shape, going from one outlet to the other (or rather, going from
> the outlet to the inlet; but you don't have to know which is which).
> This will take the heater core out of the loop. It might still fog
> a little until the water in the heater core has evaporated, but it
> should "fix" the problem.
>
> If you *do* need heat, you'll have to replace the heater core. This
> is a fairly inexpensive part (about US$100), but is labor intensive
> to replace (up to 9 hours, depending on who you ask). You can do it
> yourself; direction are on-line and in the archives.
>
> --
> Kent McLean
> 1990 V8 w/5-speed and other mods
> 1991 200 TQA #3, with mods
> 1999 A4 Avant, V6 Tiptronic
> gone: '91 200 TQA x2, '94 100 S Avant, '89 200 TQ "Bad Puppy"
>

Casimiro Izquierd,

I too have heard the siren-song of 'just bypass the heater core' (on a
different car) and I can tell you that in anything but the most mild
weather, it is an absolute pain in the arss. It is surprising how often a
little bit of heat needs to be added to the ventilation air. Without it,
it makes dealing with rain and damp air nearly impossible. My opinion.

The bad news: The heater core on the B4 series is a big project (probably
a big project on all audis). However, once you get into it, it's very
do-able.

Tom LH
1995 90>