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Whirring Noise

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Almost_There92, Jul 14, 2015.

  1. Almost_There92

    Almost_There92 New Member

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    Hey Priuschat,

    I purchased my brand new 2015 Prius four (w/ solar roof package) this past Thursday. I am loving it so far but since this is my first hybrid I am not accustomed to some the sounds it makes. I have found quite a few threads regarding weird noises but in my circumstance it is different. As the title suggests, I frequently hear a whirring noise. It sounds entirely normal (in a sense that it doesn't sound like something is broken), what bothers me is how frequently I hear it: Whenever I open the driver side door, often when I depress the brake pedal (I'm not sure if it does it while driving, too much wind and road noise, but I have heard it when braking in EV mode). It just seems to happen too often and its stressing me out. I'm thinking its the brake accumulator because that is what I read is the source of this noise. It drives great and does not seem to cause any issues. What do you guys think?
     
    #1 Almost_There92, Jul 14, 2015
  2. Paradox

    Paradox Prius Enthusiast / Moderator
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    Moved from the Prius v forums to the proper Gen III sub forum.
     
    #2 Paradox, Jul 14, 2015
  3. JC91006

    JC91006 Senior Member

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    It's the brake actuator pump. It's a normal sound to hear.
     
    #3 JC91006, Jul 14, 2015
  4. Blizzard_Persona

    Blizzard_Persona Senior Member

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    I was gonna reply the same but I don't get the "whirling sound when he opens the door" though?
    Maybe the SKS?
     
    #4 Blizzard_Persona, Jul 14, 2015
  5. Almost_There92

    Almost_There92 New Member

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    Sorry, didn't mean to post in wrong forum.

    I figured it was normal but hearing it that often?
     
    #5 Almost_There92, Jul 14, 2015
  6. JC91006

    JC91006 Senior Member

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    You get that sound every morning (or when it sits for a while).......1 time when you open the driver's door.

    The prius has electronic brakes, that's what you're hearing. You don't hear this on a regular car because it doesn't have hybrid synergy drive.
     
    #6 JC91006, Jul 14, 2015
    Last edited by a moderator: Jul 14, 2015
  7. Almost_There92

    Almost_There92 New Member

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    Ah well that makes sense. I went through the owner's manual and the included DVD, both had sections discussing 'sounds common in a hybrid' none of which were the sound I was hearing. Upon further searching I did find some threads that discuss other owners experiencing precisely what I am and the consensus is that it's the brake pressure accumulator pump.
    Thanks for your help!
     
    #7 Almost_There92, Jul 14, 2015
  8. bisco

    bisco cookie crumbler

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    that's the most common sound in the car, i can't believe it's not in the manual.
     
    #8 bisco, Jul 14, 2015
  9. Almost_There92

    Almost_There92 New Member

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    Bit of an oversight on Toyota's part perhaps but considering they made the effort to discuss 'hybrid noises' you'd think they'd cover them all.
     
    #9 Almost_There92, Jul 15, 2015
    bisco likes this.
  10. fuzzy1

    fuzzy1 Senior Member

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    Regular cars use manifold vacuum from the continuously running engine to power the brake booster. The Prius doesn't have a continuously running engine, and usually not much vacuum differential even when the engine is running, so needs another source. So a 12V pump pressurizes a reservoir.
     
    #10 fuzzy1, Jul 16, 2015
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