Mysterious buzzing at 50-60 mph

[Mass535Love]

When driving at about 50 miles an hour I begin to hear a subtle buzzing like a bee or large insect is caught in my vent or somewhere up in my dash. It gets louder up till about 70mph or so. Not sure about faster because I don't take it faster than 70. This ONLY happens if I have my fan on for climate control. Under 50 or with the fan off there is absolutely no noise heard. I know it's nothing serious but it's kind of embarassing and annoying. Ever heard of this? It seems to be coming from the drivers side defrost vent. It's hard to pinpoint it going 60ish mph and jamming your ear in the dash trying to listen :P If you want maybe I could get a recording to give you a better idea.

This ones got me baffled.

Thanks guys. I hope one day I can find something I can contribute to this forum.

[jjw]

Could be the plastic piece under the wiper is lose. Have the some buzzing before, check those piece and sure they are lose. Tighten them and went away. Well that just my experience. Hope this helps.

[Javier]

http://www.bimmer.info/forum/showthread.php?postid=47946#poststop

Javier

[winfred]

in cooler weather (starting at about 55*) my 535 would buzz till i taped the top and bottom windshield trims to the glass with electrical tape, aint herd a peep in over a year and if you look hard you can see the tape if you know to look

[Mass535Love]

I'll be sure to give these a try. I hope it helps. It seems odd though that it only happens if the fan is on and moving at 50+, without fan on there's no noise. I'll let you know how it goes. Thanks guys.