Noise from fan clutch or the accessory belt 2RZ FE with video

Just took this video. it's about 70F outside and drove for about 4 miles on highway. the front of the engine compartment is making some really huge noise. I don't have an accurate sound meter but my phone reads above 80 db with the hood open. And I am reading 85 db ish in the cab at 65 MPH.

It appears that the sound comes from the fan clutch. But I really have no idea.

110k on the truck.

Any idea?

Thanks!

http://youtu.be/8NRgMiyXTSU

 

Is your A/C on? Mine sounds kinda like that when the A/C compressor engages. It turns into a diesel like idle noise, there's lots of info and theories on it over in the 4-cylinder forum. As far as we can tell it's normal, not sure if any conclusions have been made as to what causes it though.