This was changed around 30,000 miles ago at the same time as the cambelt and water pump. I heard this strange noise while driving yesterday that sounded like a loud flapping that got louder with revs (but silent on idle). Before I could pull over safely it had stopped and I thought maybe a plastic bag had got stuck under the car and carried on driving for a few miles. When I went out again later the battery light was on so I turned around and went home. The drive/auxiliary/serpentine (or whatever it's called) belt was shredded and off its pulleys.
Does anyone know what I should be looking out for that could have caused this before I get it replaced? The alternator pulley seems to spin fine but I didn't have time to try anything else (the rest is pretty hard to get to from above). Cheers.
(2012 Passat B7 TDI 130 saloon by the way).