Eldorado ETC Engine whine? Help please!

Hi guys i am having an issue and i just cant narrow it down so i figured i'd ask my fellow Cadillac enthusiast. So about a week ago i started to notice a whine while accelerating it gets higher in pitch as the rpm's go up. I have Replaced idler/Tensioner pulley already. It doesn't seem like power steering either, also you cant really hear it when idling.....:hmm: maybe a very very slight noise. It will make the noise in park when you rev it say to 1500k+ rpms. Also after about 25 minutes of driving the noise almost goes away......Im trying to give as much information as i can think of. It sounds like it is coming from the drivers side of the engine compartment .... well thats about all i have at the moment. Hopefully someone has had this issue or knows how to fix it and could help me out i would really appreciate it. Hope to hear from you guys soon... Thanks!!!