Depending on how much metal flake, it could mean the rod bearings are wearing out. or it could mean that somethings wrong with the cams. Any car that i have ever done an oil change to there has always been metal flakes of some sort. its pretty hard to avoid with that many moving metal components. i wouldnt worry about it until you start hearing a knock.
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!