We owned a 2010 Prius 4 for 10 years and loved it. Yesterday we picked up our 2018 Prius Prime from Carvana. Driving home, my wife noticed an irritating loud buzzing from the rear area. With my bad hearing, I was not able to pinpoint the exact area of the noise. After some checking, I am thinking it is one or two of the battery cooling fans. The noise was gone when we were stopped or not going very fast. At about 50 mph, the noise started and when we were doing 78 down the freeway, the noise was very loud. Has anyone else encountered this problem? I have 7 days to return the car to Carvana but I hate to do that. I love this car!! Thank you in advance!!
I don't get any loud buzzing when driving my 2021 PP. There are battery ventilation fans in back, maybe there's something caught in one.
Is it possible to take a sound video? There are two blower fans in the back but have not seen reports of noticable fan noise.
First thing to do is try to reproduce the issue. If you can reproduce it, try switching modes EV to HV assuming you still have a little charge left in your batteries; to see if anything changes. If the problem persist, it's probably mechanical - check to see if all four tires are the same, make and model. Check for loose under-body panels or you may simply be dragging around a plastic bag that got caught under your car. It wouldn't hurt to pull those battery cooling filters, to see if they're clean. I believe there's a passive vent, lower center back seat plastic molding. Just above the rear center floor hump. You can check the traction battery blower fans by just charging the car and checking it 30 minutes into the charge cycle. Your wife should be able to hear a soft drone of the cooling fans, near the rear tires of the car. Slightly warmer air should be exiting the rear corners of the car, below the bumpers - exhaust from the blower motors. The sounds should be symmetrical on both sides, otherwise the side that's groaning has a bad blower bearing. Hope this helps...
What trim level do you have? In my wife's Limited (RAV4), when we use the cooling, ventilated seats, the fans are noticeable. I have a PP LE so don't have them. Just a wild thought.....