Technical Scraping/grinding noise alternator area

[philipb82]

Hello

Just recently i have heard like a scraping/grinding noise and seems to be coming from the alternator area. Its present at idle and when i rev the engine i couldn't hear it but then it returned when i depressed the pedal. I'm sure i also heard it when driving (low revs 30-40mph). I had a similar issue a while back but that was a squeaky noise, different to this one. That turned out to be the belt. Everything in that area is new-ish - belt but how long should they last for?, crank pulley and alternator pulley. The only thing that hasn't been changed is the alternator but i hope its not that. The car is a JTD.

Any ideas what it could be?

Thanks
Phil

 

[mhowse]

could have a small stone chip on similar stuck in pulley and alternator, or even between pulley/belt teeth or worse a bearing is on the way out would have to remove belt and give all pullies and tensioner if fitted a look at for any worn parts though you do mention all parts have been replaced, if you can not pin point the source of sound could be worth taking top cambelt cover off to inspect all is ok in there.v belt should be good for at least 50k and more if it does not suffer any unwanted splits or cracks from road debris flying into it