My car broke down on tuesday it started making a rattling noise before it ejected its alternator belt I managed to get it to citroen thinking it was just a belt but not that simple they had to put on a new alternator, belt and idler, they say it was caused by a miss aligned alternator and it had destroyed the front bearing it is all sorted now they did it under warranty it was a big job they said as the alternator is a pig to get out and a very very expensive part. So I would check your alternator or it could be expensive