Squeaking noise 99 explorer rear of 4.0 engine

I had replied to another posting of a problem I am having with my vehicle. It started 3 days ago and it sounded like a squeaking or squealing noise and got faster with engine RPM. Some times it stops for a few seconds but starts back.Its worse when cold..:frown: I thought it was in the belt area and put belt dressing on and same problem..I jumped up on top and listened and found at the right rear of engine the noise was noticed..It almost sounds like a rocker arm binding with no oil getting to it .Has any one else had this problem and what was the source..???? It has the 4.0 pushrod engine in it. I dont want to start digging until I get some ideas..HELP Thanks Deerecrouse