Hi all, When starting my A6 2.7T from cold it produces a constant pitched noise for about a minute or so and sounds quite nice. I assumed it was something to do with the turbos or something warming up. I recently (about a week ago) started the engine and got the same noise but a hell of lot higher in pitch. Again it went away after a minute or so. It has not happened since. Does any one know what this noise is? Regards ajek.