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Noise from rear - cooling fans?

Discussion in 'Prime Main Forum (2017-2022)' started by Inspectorman, Oct 8, 2021.

  1. Inspectorman

    Inspectorman Junior Member

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    Vehicle:
    2018 Prius Prime
    Model:
    Plug-in Advanced
    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!!
     
  2. DukeofPrime

    DukeofPrime Member

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    Vehicle:
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    XLE
    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.
     
  3. bisco

    bisco cookie crumbler

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    is it hot there? might be worth checking the fan blades. how many miles on her?
     
  4. Marine Ray

    Marine Ray Senior Member

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    Plug-in Advanced
    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.
     
  5. BiomedO1

    BiomedO1 Senior Member

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    Vehicle:
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    LE
    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...
     
  6. Kirk Bethel

    Kirk Bethel New Member

    Joined:
    Feb 11, 2022
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    Location:
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    Vehicle:
    2022 Prius Prime
    Model:
    LE
    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.....