|Originally posted by Notorio:|
Glad to see that you weren't invaded by varmints. Perhaps the moaning sound will become a unique feature of the car that will grow on you over time ...
It's rather unpredictable so I doubt I can just get used to it. haha
Another Fiero owner mentioned that it might be old, collapsing vacuum lines feeding the climate control system. I also could have a small leak which is causing the collapsed lines to "moan" as air is pulled into the line. Like I said earlier, the noise is similar to a balloon squealing when outlet is pinched and air is released. It's hard to believe that nobody has experienced this. I will investigate under the dash this weekend and report back.
I hope I solve this issue. Maybe this thread will help others in the future.