Hello, I’ve recently bought a 2019 AWD XLE and when i was on the test drive i noticed a humming from the rear. I guessed that it was a wheel bearing since it seemed to sound the same and change when turning and with speed. I replaced one rear wheel bearing without giving the wheel a good shake to feel for looseness because i was confident i knew the issue, but the noise hasn't gone away. Could it just be road noise? This is my first prius and didnt test drive any others so I dont have a baseline. Any other ideas what it could be? I plan on changing the transmission/dif fluid soon anyway.
Did you check the fluid level in the pumpkin and/or has it been ever checked or changed? This is neither here or there; but why did you buy it like that and not insist on them fixing that first? Has that car been in an accident before?
104k miles so far, I was thinking (hoping) that it could be the other side too; I will have to take a closer look. I should have mentioned that the tires are brand new so I dont think that would be the source. I haven’t checked the fluid yet, but thats a good idea to check/change. Am I reading the manual right that it takes ATF? As far as buying it with an issue, there aren't many used in my area and it was a reasonable price so I figured it was worth the hassle of tracking down the noise, especially since I was so sure it was the wheel bearing.
It might also be the AWD rear wheels electric motor. Don't know anything about the AWD version but I think it is AWD all the time. There might be some additional sounds associated with that.
From what I can tell, it’s not using all the wheels all the time. When I pull up the diagram on the dash, it shows what power is going to which wheels, and usually it’s just the front. When I have time, I’ll look into it more.
It takes Toyota ATF-WS, have 2 qts on hand and you will use bit less than that. Rear motor only engages during first start from full stop up to like 7-8 mph from stop to assist in initial acceleration, and when wheels are slipping in snow or ice as needed, but this also happens only under certain mph, like in the 30s or less I believe
