I have a "rattle" on my 2003 R170 when I increase revs from tickover and when decrease to tickover. This only occurs at initial increase ie 1000-1500revs and the same coming down. I thought it was the CAT rattling, but an independent Merc mechanic immediately on hearing the noise said it was the cam adjuster "kicking" in & out and was normal! Good news you would think, but I'm not sure as it seems quite loud and I don't remember hearing it on the two other SLK's I tried when buying. What do you think? I would, as usual, welcome any comments on this. The engine, a M111-958, runs & sounds smooth, so am I concerned about nothing? Cheers. Owen.