Considering that it is intermittent, the only suggestion I have is to make good observation of what the circumstance is when it occurs. This can be as specific as you can be, like temperature, speed, modes of hvac operation(recirc/defrost), etc. When it does occur, does it occur at speed as well as when the vehicle is stationary? To give you my background, I am, and have been a Cadillac technician for over 12 years. Intermittent problems are very challenging, and the most information that can be given for one to attempt to duplicate the concern, is critical in success of repair. With the concern that you are describing, it is more of a nuisance, than it is a safety concern, so operating the vehicle with the condition may be unacceptable, but not detrimental. If by chance you can demonstrate it to the dealer staff when it happens, then that provides the validity for them to address it at all odds. A suggestion to try as well, when it is making the whistle, does changing the blower speed change, or diminish the frequency at which the whistle occurs?
Saturday, January 29th, 2011 AT 4:03 AM