On Apr 9, 1:17 pm, wrote:
> Got an 03 A4 1.8t. Lightly chipped and no other modifications.
>
> Heres the issue. Under acceleration I can hear a hiss from the engine
> compartment. No noticeable change in performance but sometimes when I
> come to an idle, its rough and I can hear a little hiss. I get out..
> pop the hood and identify the source of the his... and give it a
> thump. The valve snaps itself together, the hiss goes away and the
> idle returns to normal. What valve is this? Does it normally snap
> apart like its doing? If I removed it from its assembly I believe it
> would just fall apart. Is that normal?
>
> http://jake.rakestraw.com/images/engine.jpg
> This is a shot of the engine compartment with the questionable valves
> location circled.
>
> http://jake.rakestraw.com/images/valve.jpg
> This is the actual valve. You can see the dust free fingerpriunt on
> the side when Ive been pushing on it to pop it back into place.
>
> Any ideas?
>
> Jake

Its not normal. i'm forgetting the name for it and its proper
function, but its part of the vacuum line and its linked to the brake
system. Apparently its a pretty common problem with Audi. I just
taped the split together (where it keeps popping out from) and drove
my car for about a month until I got a chance to change it. Easy fix,
took about 30 minutes in all, part cost less than $50