I had a timing chain, guides, etc. done about 6-8 months ago and didn't have any ticking noise that I can remember, at least it was not as noticable as it is now. I never noticed the ticking noise until I had problems with the plugs and wires causing a really bad idle. It ended up being that 1 or 2 of the plugs were not even firing. I asked the German mechanic what I could do to quieten it down some and he said get rid of the synthetic oil and use 20w50. In my area, 20w50 is not a good weight to use and I thought that was sort of a cop-out answer. He said that mercedes has said not to use synthetics. I find it funny that Mobil 1 states right on the bottle that it meets all guidelines for MB, Porsche, and other European sedans. Not getting into the synthetic-or-not discussion that I have seen on these boards in the past, I personally feel the syns are slicker and reduce the wear on the engine over time. I have had nothing but good luck with syns. But, back to the noise, it is not real loud and today it must have been there, but I didn't notice it like I did in the past few days. I know the noise comes from the passenger side valve cover. The driver's side is completely quiet. Thanks for all responses.