Need help identifing engine noise!

[caniborrow50cnts]

For starters, I have a 97 eclipse, 2.0 non-turbo, stock with the 420A engine. No mods at all.
During acceleration from about 2500 to 7500rpm, I can hear a high pitched whistling sound coming from the engine. I know it is not neither the alternator nor the PS/AC belts since I took those off and it still made the noise. I can shift into neutral and it will still do it when I rev the engine. I have also noticed it only does this during acceleration. The car does not have to be moving for it to sound. I have narrowed it down to two possibilities but I wanted to get your opinions before I started pulling it all apart. Any other questions or descriptions needed, just post and I will reply. Any help is appreciated.

[EclipseRST]

check all your vacuum hoses... sounds like a vacuum leak! expecially the hose running from the valve cover to the manifold

[caniborrow50cnts]

I thought it may have been a vaccuum leak though but when I checked them, they seem to be just fine. I will check the manual though to make sure something isnt missing because that just seems to be the most likely cause. Any other thoughts out there?

[mustange kiler]

my car makes the same noise i havent check yet because i like the sound of it

[mustange kiler]

it sounds like its comming from the right side when im driving

[caniborrow50cnts]

i know, it sounds like a turbo charger but without the blow off valve. Reguardless I still think it would be better to locate the problem.