Hi i'm a new member to the Mercedes family. I recently bought my first. Once I drove the car i fell in love with it. It's been beautifully maintained on the outside and rides like new. But upon removing the oil fill cap to do my first oil change I noticed sludge buildup inside and the oil seemed thin and burnt and after listening closely i can hear tapping. The engine has 100,000 miles and i was thinking about flushing the oil to see if that helps. Does anyone have an opinion on this, or any recommendations before i do.