I had my done in March of 2004 on my ML 430 at 100,600 miles. The dealer wanted $1,600 for it [xx(]. My mechanic done it for $143.00. I would say that the loud clattering noise (sounds like your engine is flying apart! Scared the S*&% out of me) coming from the engine is a good sign you have a problem! If it goes at the right time, it will tear up hell and half of Georgia[:0]. Raise hell until they replace it under the "service campaign" (not recall). I intend to do just that to get my money back for mine and to see if they will replace my damaged oil pan and timing cover that we filled with JB Weld. Good Luck!
Unless you only do short journeys I would not wait for it to come apart.
I had one come apart on a BMW R69S motorcycle and it did some damage to the front engine cover.
Besides, it stops functioning as it should (cancelling out vibration) before it comes apart; it is much better to get it done on your time scale, and at a place of your choosing, than waiting till there is expensive collateral damage.
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!