yes deefinitely be careful with the whole pully end of the engine!
I was poking around my uncle'* regal (3800 series 1) and i STUPIDLY put my hand down "wherever" and "Wherever" happeend to be the alternator pulley'* fan!
I thank GOD that somehow it just sorta bit my hand and spit it out because i know for CERTAIN that a hand or fingers easily get stuck in that alt. pulley and I don't th ink i have to tell you that an engine is MORE MORE MORE MORE MORE than capable of destroying measily, weak bone!
With that out of the way, I bet it is a vacuum leak. I used to hear an electronic "wine' come out of my engine somewhere which was audible while i was in the car driving! I don't know what it was but (for the record my uncle'* buick regal had it too). I think with time it has gone away (but i have replaced most vacuum lines since then so it might have been that!) but let me just say that my brother'* ahem.. mitsu eclipse
... makes it too and he knows for sure its coming from his fuel pump, so i just wanted to give you that idea to listen for. (maybe its coming from towards the back).