Hi, I have a 1997 E300TD with 90k on it, on start up its silent but once you start driving and you ease off the gas if the revs drop to 1200rpm to tick over it sounds horrible like there is no cam tensioner even fitted, and from the lights it seem very lazy to get going, once its over 2000rpm it pulls silently and strongly with no smoke, only when the engine is at low revs while warm this happens, it uses no oil but will only return about 27mpg with normal driving. so i suspect something is defiantly amiss?? I would be grateful for any advice you may have to help me correct this, many thanks steven.