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Re: Crankcase Breather Question



In a message dated 9/9/99 2:51:11 PM Eastern Daylight Time, 
schulz@iatcmail.ed.ray.com writes:

> I think that I found the source of my hard starting problem-
>  Crancase breather hose was collapsed, AND has a hole in it...
>  
>  Other than making the engine run a bit roughly, are there any
>  other issues if I need to drive the car before I replace it?
>  
(snip)
  
>  Sidenote- on the 20v NA motor, the 7A, Audi created an "upgrade"
>  that replaces the section of the hose that tends to degrade and collapse
>  with a metal section (installed it in my CQ).  Of course they didn't do
>  the same for the 3B in the 200, and since the hoses have different
>  bends, it's not a swap.
>  
>  -Peter Schulz
>  1991 TQW
>  1990 CQ
>  schulz@res.ray.com

Couple comments:
Should be able to run the car fine; at cold start, the engine assumes the 
air/fuel mix needed, since not enough air is flowing past the mass air flow 
sensor to be read correctly; you're adding in unmetered (or should I say, 
unanticipated) air, so your startup mix will be off.  Once the car is going, 
it should be ok... but that could be a partial cause of your poor mileage 
lately...I think this hose is a good 100k interval replacement candidate...

There's some kind of one-way valve to keep from "pressurizing or 
depressurizing" the bottom end under boost conditions... I think the addition 
of the turbo makes the n/a 20v crankcase breather system a bit different...
reportedly, if the hose clogs up and doesn't allow pressure exchange, the 
pressure must go somewhere... likely right up and out through the 
distributor, for example.  Sound familiar to anyone?  I think a metal fitting 
would tend to collect and clog more than the rubber one which would burst 
(i.e., be quite soft and let go under excessive pressure).
be careful on removal to not dump all the accumulated sludge back into the 
crankcase... you might want to slice the old hose off, and be prepared to 
clean out the metal fitting on the engine...
also, don't forget to pull the flame arrestor out of the old hose and 
transfer it to the new one.  Not too bad a job over all, IME... see scott 
mockry's page for more details.
Scott is at:
http://www.sjmautotechnik.com
hth, chris miller, windham nh, c1j1miller@aol.com
'91 200q20v ==> http://members.aol.com/c1j1miller/index.html