2010 c300 high pitched whistle in cabin
Just took the car to the local dealership and the mechanic heard the whistle, he agreed that it was noticeable under acceleration and at cruising speed. After further inspection metallic debris was found in the oil pan. New transmission was ordered and installed. Just got the car back from the dealership today, as soon as I hit the highway I could hear it again. I have a call in to the dealership again.
ANY IDEAS??


