I have a 2001 audi a4 with 70k miles and just noticed rattling (pretty loud noise) from the front of the engine. It seems to be coming from the alternator but I'm not totally sure. Any info on this problem would help Thanks.

 

When does it rattle?

 

The rattle occurs worst at idle but does it while driving too. I really think it's the alternator, but thought I would get some other Audi owners opinions