[Biturbos4] B5 S4 heater core clogged

[Kneale Brownson]

Not a B5 guy, but on my C5 A6 Allroad, when I did the belt/pump/t-stat, I had to play with a bleeder in a hose between cylinder banks to get heat back. 

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> On Dec 26, 2013, at 10:48 AM, Ti Kan <ti at amb.org> wrote:
> 
> The thermostat was defective and replaced within the past week,
> along with a full timing belt job (water pump, tensioners, etc).
> The coolant temp gauge now reads normal, and it rises to operating
> temperature quickly, but still no heat from the vents.
> 
> -Ti
> 
>> On Thu, Dec 26, 2013 at 12:36:18PM -0500, Greg Amy wrote:
>> Are you SURE it's a blocked heater core? I had a heat issue with my B5-S4 and it was the thermostat. Secondary symptom was the water temp gauge* reading oh-so-slightly lower than in did in summer. 
>> 
>> Block off half the radiator with cardboard and see what happens. 
>> 
>> -GA
>> 
>> * Modern cars' temp "gauges" are nothing more than pretty idiot lights. Most take a lot of change in value to show a slight change in gauge position. 
>> 
>>> On Dec 26, 2013, at 12:03, Ti Kan <ti at amb.org> wrote:
>>> 
>>> Hi all,
>>> 
>>> The heater core on my 2001 S4 appears to be clogged, there is
>>> very little heat out of any vent even with the engine fully hot
>>> and the climate control temp set to HI.  The blower is working
>>> properly, all air flaps seem to work too.
>>> 
>>> Replacing the heater core is a BIG job on this car, involving
>>> the removal of the center console, entire dashboard, and many
>>> things beneath it.  I don't have the time or the confidence
>>> that I could do this myself, and paying a shop to do it will
>>> be serious $$$.
>>> 
>>> I read that a heater core can often be un-clogged by backflushing
>>> with either compressed air or water.  My mechanic is reserved
>>> about this method, saying that there is high chance that it
>>> would cause the heater core to spring a leak into the cabin,
>>> which would _force_ a replacement of the heater core.
>>> 
>>> What is your opinion about this?  Should I try to backflush it?
>>> If so which is better, compressed air or water?  Just how sturdy
>>> are these heater cores?  According to the family album the same
>>> heater core is used on all B3, B4 and B5 Audis as well as the
>>> B5 Passat.
>>> 
>>> -Ti
>>> 
>>> 
>>> 
>>> 
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> 
> -- 
> Sent from Main Mission
> 
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