Hello to everyone. I have used a Hymerwohnmobil integrated with engine 519 CDI. The vehicle has a warranty until Oct. 2014. When the vehicle is accelerated and the engine is warm you hear an additional noise. It sounds like something is rubbing or grinding. Three workshop visits at different Mercedes houses did not help. All companies have confirmed the disturbing noise but finally defined it as the state of the art. Who knows the problem and can keep me going. lfen? I am grateful for any answer. hweinz