Here's a squeak I had in my Camino 3 years ago.Would start once the engine warmed up a bit.It really challenged me.I used a stethoscope to track the noice down and the old long screw driver trick.The sound seemed to travel.Took off all the belts...still there.Changed the water pump and distributor...still there.I was at my whits end.One day got angry and decided to take the Camino on a long highway ride at 70-75 MPH's.Squeak went away to never be heard again.Here's a YouTube video.Check it out and see if it's a similar noise.
https://youtube.com/watch?=0Hx802HyWs&feature=share