Hello there, My prius at 225K miles after a 2000 mile trip started making a strange sound particularly when you are going uphill, but lately audible at lower RPMs and speeds when you are accelerating.. This was recorded at about 75MPH going uphill Recorder It sounds as if the car is revving up and down but RPMs were constant 3800. Battery level seemed normal at 75%, car responsive as usual. Just this sound that almost sounds like the sound from a food processor, like something spinning around if it makes sense. thank you in advance!