i have the same thing on mine someone said it was because of the amp

 

get some magnaflows and you wont hear anything lol

 

Are you married ? If so try removing your wife from the passenger seat and see if the whining noise goes away

 

Thanks for all the suggestions. I have an 06 Megacab with ~75K miles that just started making the noise. Sounds like the whine of a blower. All the same symptoms: isn't affected by turning the steering wheel, louder at higher rpms, doesn't go away after warming up, power not affected. I'll try the belt suggestions.

 

I had that problem......then my power steering went out!

 

I was having the same issue, and I just lost the belt and idler pulley on the water pump....now I have to figure out how to get whats left of the bearing off so I can replace it....all thats left is the inner part of the bearing...HOW THE HECK TO I GET THAT OFF?