Hi,
I'm new to your post. I'm using a 2007 Mercedes GL320 CDI. It's around 100000km. From 85000km to now it started to make some problems. Main problem is the engine vibration. Around 1000-1200 rpm engine make vibrations like knocking and after 1200 rpm car returns to normal. I bring it to the dealer and they updated some kind of software on the car, but the problem still continues. Please help me find a way

Regards