[PunjabiM3]

This is my eighth BMW since 2004 and none of them have made this noise. It is not a faint noise or the sound of something priming; rather it is a loud, startling grinding noise that lasts for about a second. You can hear it both inside and outside the car. I believe even if you were standing around 25 feet away you can still hear this noise when the car makes it. I believe it to be some sort of faulty part from when the car was built. We ordered this car to spec and my plan was to get an extended warranty and keep it past the original 4 yr warranty. However, if the cause of this noise and resolution cannot be found by BMW, then we likely won't keep it past the four years.