All,
Sorry if this is a repost, but I've dug through quite a few threads regarding this similar sound and I need some guidance. I have an 08 M3 6spd with 56k miles. Over the last two months, this sound would arise during cold starts on multiple occasions. The sound goes away after 5 minutes of driving consistently. At first I thought it was the belt, but the belt dressing didn't do anything. My next assumption would be the idler pulleys and tensioner. I took it to my indie last weekend and he couldn't diagnose it right off the bat, but suggested I replace all belts, idler pulleys, and tensioner to be safe.
I held off on it to research more. I came across some power steering fluid threads and decided to check mine. It was low so I went to the store to pick the CH11S fluid and topped it off. This morning the car sounded fine, but I'll monitor it over the coming days. Does this problem sound like it's too soon for any of this stuff break down? I've seen 80-100k mile M3s where the idler pulley or belt needs replaced, nothing under 60k miles. I appreciate everyone's time and thoughts.
<iframe width="420" height="315" src="//www.youtube.com/embed/XKDsd7gBgc0" frameborder="0" allowfullscreen></iframe>
http://youtu.be/XKDsd7gBgc0