Searching the net and I came across this thread, my W211 220 is making a noise from the front, low speed over rough surfaces and I just can't get to the bottom of it. Even describing it is hard, it's not a knock, more a very low tone squeak, not high pitched. Took it to my local and very reputable garage who said yes we can hear it, but they can't find anything wrong with it, which in some ways made me feel worse
.
I wondered if it's the shocker.
I'm going to have to look at it myself as it is really getting on my wick, I gave a colleague a lift yesterday and had barely moved off and he came straight out with, 'has this got a knackered drop link'. What a pain in the backside this is.