ORIGINAL: Blinkstang

So I have an 02' GT, that apparently thinks its a Cobra because it likes to hiss at me. When my car is idle or at a stop, it makes this on and off hissing sound. It could be happening when Im moving as well and I just do not hear it over driving noise.

Its coming from the engine, I opened the hood and its real loud when open. It hisses as I said, on and off. So like hiss hiss silence hiss hiss hiss silence. The silence is only like for a second or less. Is this normal or do I need to call animal control? My driving is normal and it does not seem to affect anything, so I thought it might just be a normal engine sound. But I do not remember having this sound on my previous 96' GT. Do I have an air leak of some sort? Thats what it basically sounds like, hissing air shooting out.

So what is it? Bad? What should I do?

Thanks guys!

Info:

2002 GT, Manual
No Engine Modifications (Yet...)
(Happens with A/C On or Off)