its not the guages, those sound like a oven timer. i have the "turbine" sound as well. it has always done it, so i a not too concerned with it. i have had my stang for a year and a half and no problems from that sound yet.
I noticed mine does this when the air conditioner is on when I'm driving and then turn the car off. I don't notice it at all when I don't run the air conditioner.