Neight

Hello all, I have had a look through the forum to find an answer to this, but had no joy so far. So I thought I would put it out there to you guys. I have had my 2011 B160 Sport (35k, full MB history) for about four months now and recently have picked up on a knocking/rattle sound on start up which disappears when pulling away and idling after. I have a couple of months left on the warranty, so if this is something big, I'm pretty keen to get it diagnosed.
It is relatively intermittent which doesn't help, but it sounded particularly bad the other morning, so I videoed it. When it was this loud, it was obviously coming from the drivers side, where the belt is.
Could I ask you have a look and maybe share your thoughts? I really appreciate your help if possible.

Black Forest

That sounds like the timing chain. I would start by isolating the sound using a stethoscope and good chance you will need a tensoner. Dealing with that currently myself..