Here is that defective Apple Macbook called mooing
If you’ve been keeping up with MacBook sans-Pro news, you may have heard something about an infamous “moo”-like noise coming from the fan. Basically, the fan goes on and off and on and off and on and off continuously, in a vain attempt to keep the machine cool. Now, I’m no engineer, but it certainly doesn’t take one to recognize that this isn’t normal behavior…source
I think this can easily be fixed through a firmware update. Saying that the mooing is normal is not comforting to Macbook users. Besides , it was a Macbook employee who said this. It’s not the official APPLE word.