A/C Sounds like NOS purge

[99Camaro99]

First off...in the topic I could have said nitrous purge but NOS is shorter

Anyways check it out guys. If you have an older F-bod...say 99 and older (tested on my buddy's 98) and you turn the A/C on, it'll make a low bang sound, BUT WHEN YOU TURN IT OFF, it makes a hiss sound which is similar to a nitrous purge. It's kinda loud (once you turn the radio off) and it sounds cool from the outside. :D

[Ted]

Does your a/c work if not you might have a vacuum hose off or leaking. Theres on leaking on my car now so the top half of the a/c doesn't work and you hear that hissing sound somewhere in the a/c compartment. I have to track it down and fix it.

[99Camaro99]

nah A/C works and blows REAL COLD air so there is no problem. I brought it in (when under warranty) and they told me it's normal. Damn biatches too lazy to actually try and fix something

[vtv6firebird]

Yeah, mine does the same thing. Not really loud, I would say more like just barely audible, but its there.

[Shadly]

AC vents and ducts are vacuum operated. It's normal.