Quote Originally Posted by Umai Naa!! View Post
It's the vacuum system pressurising back to atmospheric.

Nothing to stress about. They all do it.

i drove a few 1.9s that never done this.



Richierich. in a 2.5, the n75 valve, perhaps called boost pressure regulator.(correct me if im wrong) can make the noise you describe. im not sure if the 1.9s have them but i guess they would.