Click on the chain detail picture to see video. enlarge at the bottom of the video screen white arrow.
The poly V belt and Timing chain set up are the same as the W168 :- mypage 57.
I have received few complaints about the W169 timing chain
However if you are suffering from engine noise do not discount the timing chain even at low mileage, Karni Singh has just found it necessary to change his chain at 50000 miles, that is less that you would expect from a cam belt NOT Good lets hope it is not a common problem.
I also changed the chain guides and crankshaft seal also the tensioner
The chain needs a special tool to join the link them up as the bicycle ones are too big
You can use a punch I have in the past but invested in a special tool this time round.
This was done on a sloping drive by a fully qualified mechanic of some 20 years experience, It has been done DIY but be aware it is a big job although very worthwhile when done, and the engine will not last long if the chain is left in that condition so it is a must one way or another.
Yes there is a lot of information on this site but you still need determination some knowledge and tools to tackle this sort of job.
Bear in mind this is precisely the condition a W168 W169 and 'B' Class model chain can reach at which point like Karni'e chain it can jump the cog's, in his case it only moved one tooth, any more and I am sure the engine would have suffered damage