Ok, another strange question about the car. There is a weird sound coming from the engine that almost sounds like a vacuum leak of some kind. Almost like air being sucked through the PCV valve or something. The car runs fine and idles fine, but the noise is very distinct especially when the hood is open. Is this a normal sound or what? I can’t really place where the sound is originating from other then the top of the engine somewhere? Anyone?

2003 GT by the way.

 

I had the same type of noise that you describe and it was the PCV, it was stuck open.

 

you're probably just hearing the IAC

 

On the stock TB there is a screw plug that tends to fall out. If it's been out a while the ECU may be compensating for it and would drive practically normal. (Or what seems to be normal after a period of time.)

 

Thanks everyone. I will check those things out. You would have thought the dealer I took it to for a buyers check would have noticed the sound and told me about it. I will let you know what I find.