2 ODD NOISES

[mr61buick]

I have a 2005 F350 6.0 whith 97000 miles. The first noise I have is a loud howl what I believe is coming from the turbo between 8 and 9 pounds of boost at any RPMs. It is not your normal whistle. Other than this noise, the turbo sounds the same as its been since new and there is no loss of performance. This started about 2 months ago. Is it something I should be concerned about?
The second noise that drives me crazy has been around for about a year, slowly getting noisier. I do believe it has nothing to do with the turbo. It is hard to describe. It sounds like an idler pully wobbling. Does it any gear, but precisely 12 to 1500 RPM. Takes about 15 minutes of run time to get hot enough to make the noise. I've checked the idler pulley and it seems to be fine. Maybe a heat shield? It makes the noise under light acceleration to a normal cruise speed, on the throttle hard or off the throttle it doesn't make the noise. I can powerbrake the truck and hear it. However, I can't listen to it under the hood and powerbrake it myself and my girlfriend would probably run me over if I had her do it. Everybody else just says the truck makes a whole lot of diesel noise anyway. If anybody can shed any light on this that would be great, thanks.
Eric

[nitemare50]

i am amazed that nobody on the site can diagnose the howling/ whistling sound from the turbo on these trucks i have came across a handful of these threads and nobody has a clue