Well, it looks a lot of people are having noise issues under the hood.
Here's mine, starts squealing at about 1500rpm, stops at about 2500rpm. Nothing changed when I lubed the belt. I can hold the rpm at 2000, and when I turn the steering wheel, the noise stops, as soon as I stop turning the wheel the noise comes right back. PS reservoir at correct level. PS Pump? Any ideas??? 06 F150, 5.4L Dave

 

what happens if you take it to a slightly higher rpm and then turn the wheel? Like 2750 or 3000? can you make it do that while turning?

I'm thinking that it could be p/s, could just be a belt issue. But seems that the more load you put on the belt the more it should slip. If it where me, I'd replace the belt and bleed the p/s system. Shouldn't cost much and will significantly narrow down your noise.

 

Thanks man.....actually I think I found the problem. The top idler right next to the ps pump. It was kind of weird...noise only happened between 1500 and 2500, and when I would turn the wheel it would stop. I removed the air intake and used my stethoscope, pump was quite, idler squealed like a pig. Took it off and the bearing feels good, but going to replace it today, along with the belt.