Rattling/whirring noise in idle and deceleration on 1997 Dodge Stratus

My daughter's car has been making a rattling/whirring noise while it idles and upon quick deceleration. It has been doing it off and on, but frequency seems to be increasing.

2 answers 1 comment
yes it could be your serpentien belt needs a bit tightening. Or it could be pully?
Thank you both for your responses. It ended up being a loose bolt in the flywheel. Thank goodness it was an easy and no-cost fix!
Try having the drive belt(s) removed to see if the noise goes away. If so then it is a driven componet causing this. Alt, tensioner, idler, ac compressor bearing etc. Hard to say without hearing and testing it!