One problem related to engine grinding noise has been reported for the 2012 Mercedes Benz ML350. The most recently reported issues are listed below.
From the day one, during the first 25 minutes of driving, my new 2012 mb Ml350 vibrates and make grinding noise just in between 40 to 45 miles per hour steady driving. After about 30 minutes of driving, the vibration and the noise are not noticeable. Mb and the dealer were trying to fix the problem but failed to resolved the problem. Now, they have concluded that the vibration is normal and is characteristic of the car. Any problems mb can't solve is normal!! what kind of car is it that vibrates for first 25 minutes of driving at certain speed is normal!!.