Yesterday my 2003 Vibe started making rattling noises from the area around the generator and belts. I was doing errands and every time I started up again it got worse until it sounded like I was driving an old Model A. I recorded the sound and sent to my Email Auto Diagnostician (dad) and he said it sounded like an idler pulley problem. I've read some of the posts about such rattling sounds that mention replacing the belt tensioner, serpentine belt and/or idler pulley.
My question: how can I tell which one (or ones) need replacing? (I'll be doing it myself.)
thanks
Raz