Hey folks! This one was easy to get around, look at the tensioner, it moves up and down a lot, not correct at all, easy solution, new dynamo tensioner, such an old B6 is much better at idle after tensioning, but remember the belt as well.
Soory for bad qualtiy on the video but you can see and her the fault and the camera not record the audio perfect its not soo much ide noise but its much from the tensioner.