Whisling/Buzzing noise at higher speeds-2010 Explorer

[Havfun]

I have a stock 2010 Explorer, EB, 4.0L. Very early in the life of the car we noticed a kind of whistling buzzing sound that happens only when it’s hot out and at higher speeds like 60 MPH but it happens less often at lower speeds too. It’s hard to pin point the location but it seems to be coming from the front passenger side of the car. The car has 31K miles now so I’d like to get this fixed while it’s still under warrantee. It’s tough to repeat the problem since it only occurs when it’s hot out and I can’t always run to the dealer then. I’ve seen similar posts at other forums but no solutions offered. Here is a link to the exact sound posted by another 2010 Explorer owner with the same problem.
http://www.youtube.com/watch?v=7wz6aeWdr-Y
Can anyone help with this?

 

[edwx]

Just a stab. Do you have an antenna? Wiperblades maybe? Hopefully someone with same problem will chime in.

 

[pb3]

+1 on the antenna. from the front bumper visually check and see if it's bent out.

 

[waskly]

its a normal sound that happends. turn the ac off and put it back on it should stop. for some reason you hear the vacuum canister deplete / refill.

 

[granadojl]

Those are all good ideas. I had the same exact noise happen in my '06 EB 4.6, and the noise only got louder when I kicked the A/C on. I couldn't figure out the problem... until one night I decided to run the engine without the Belt. yes, I said it. I removed the Belt and ran the engine for 15 seconds, and revved the engine to 4000. What do you know the problem was gone... I found it was the smooth idler pulley on the driver side. I replaced it and bam, the problem is gone. I believe there is a smooth idler pulley on the passenger side too. Hope that helped out. If anyone needs instructions.. I can record/document these steps.. it's super simple, and after doing this 5 times. I can swap the pulley in 3 minutes. yeah, I timed myself. Good luck.