Recently I started hearing a strange noise when I rev the car up with the clutch in. If I rev it, right when I let off the gas I can hear a whirring/rattling/loose sounding something or other sound for a brief moment and then it goes away as the revs start to drop back down. I can only hear it for the brief moment between letting off the gas and the revs dropping back down, like at the peak of whatever RPM I revved it to. Any suggestions would help. Thanks