Hi everyone, this forum is a great source of information, Thank you. Just as an Introduction I am Alex. We have a mercedes 2002 A140 long wheelbase that we have had for 5 years now, she has covered 70,000 miles. We have had the MAS done on it and now it seems that there is a timing chain issue, it started as a gentle whurring noise but over time this has developed into more of a knocking rattle. I took the poly V belt off and ran the engine and the noise has persisted. Does anyone know if it is possible to replace the tensioner without dropping the engine? has anyone done it? any help would be massively appreciated.