dragonfly noise every three minutes

[Louv]

Car: 2007 Z4 Coupe 3.0si

Problem:
Every three minutes my car makes a very quiet, "dry insect wing" sort of noise for about 1-2 seconds. It seems to come from the left side of the car, but I can't really tell. It has to be very quiet in the car to hear it. Driving straight on a freeway is the time I notice it. I've never noticed it while driving on mountain roads, but that doesn't mean it doesn't happen, as it is very subtle. My wife can hear it (while riding in the passenger seat)

I think that I can feel a very, very, very slight slowing of the car. But that might just be my imagination.
It happens in the dry, as well as in the wet, which leads me to believe it is not the "keep the brake rotors dry" feature.

Anybody else experience this?
Has this been discussed before? (I have no idea what to search for)
Any clues?

thanks for any help... sometimes it drives me nuts.

 

[ovrkll]

:idunno:
Not the response you were looking for, but I have never heard of this problem before.

 

[Louv]

Thanks... It is so regular and consistent in duration, that I'd almost swear it was something the car is supposed to be doing.

I'll wait to see if anyone else has ever heard anything like this before reporting it to my Service department (and getting that "uh... yeah... whatever... just deal." response from them)