08 E350 4matic 110k miles. Noise just started at speeds over 40mph when letting my foot of the gas I get a very high pitched loud squeal/whine noise. 1st noticed it at about 60mph very loud all the way down to about 35 then kind of fades away.The car runs and drives fine no shifting problems no vibrations no change when touching the brake. Noise goes away as soon as there is pressure on the gas pedal. Any ideas anyone, trying to avoid a MB dealership charge.