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What is the source of this sound?

Discussion in 'Prius c Care, Maintenance and Troubleshooting' started by Phil 29 Palms CA, Oct 29, 2012.

  1. Phil 29 Palms CA

    Phil 29 Palms CA Member

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    When my Prius C is in the garage for awhile and then I open the driver door to get in the car there is always the sound of a running motor - "rrrrrrrrr" coming from the engine compartment. The sound is of a motor running. The sound always lasts the same lenght of time - about 9 seconds. Then the sound stops. Since it happens all the time, I think it is part of the Prius C computer start-up software program. CAN ANYONE REPLY AND TELL ME THE SOURCE OF THIS MOTOR RUNNING. Is it the power steering motor or a fuel, oil or cooling pump? I would appreciate a reply! thanks! PHIL. 29 Palms, CA.
     
    #1 Phil 29 Palms CA, Oct 29, 2012
  2. Rob.au

    Rob.au Active Member

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    #2 Rob.au, Oct 29, 2012
  3. brucepmiller

    brucepmiller Member

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    The hybrid system works most efficiently when it is warm so the folks at Toyota have tried to help it along using the heated coolant from your last drive. Basically when you turn off the car a small amount of heated coolant is kept in a reservoir. The next time you get ready to start the car (when you open the door) the warm coolant is pumped out of the reservoir with the intent of speeding up the warming process and getting the hybrid system working at peak efficiency. The pump is activated when you open the door, be it five minutes after to shut down the car or eight hours.
     
    #3 brucepmiller, Oct 29, 2012
  4. Oldwolf

    Oldwolf Prius Enthusiast

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    The Prius C does not have the coolant reservoir like the Gen 2's do. I think what you are hearing is the brake pump keeping the system pressure to whatever pressure it is supposed to.
     
    #4 Oldwolf, Oct 29, 2012
  5. Phil 29 Palms CA

    Phil 29 Palms CA Member

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    When I open the driver side door to get into the Prius C I here a motor sound like "rrrrrrrrr" coming from the engine compartment. The sound lasts for about 9 seconds then stops. It occurs every time I enter the car. I think it is part of the Prius C start-up software program. CAN anyone reply and tell me: What is the source of this sound? Is it a power steering, brake or coolin pump motor? PLEASE REPLY.
     
    #5 Phil 29 Palms CA, Oct 29, 2012
  6. Paradox

    Paradox Prius Enthusiast / Moderator
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    It's the brake boost pump building up pressure.
     
    #6 Paradox, Oct 29, 2012
  7. Phil 29 Palms CA

    Phil 29 Palms CA Member

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    Thank you brucepmiller. Your reply seens to be the best reply answer. I tried finding an answer in my owners manual with no luck. Where do you get your information to some hard to know questions? Is it in Prius Chat? PHIL 29 Palms
     
    #7 Phil 29 Palms CA, Oct 29, 2012
  8. Paradox

    Paradox Prius Enthusiast / Moderator
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    I'm not ultra great with exact information for the Prius c but I thought the Prius c used the exhaust heat recovery system introduced with the Gen III Prius doing away with the coolant reservoir that was found in the Gen II which is what brucepmiller is referring to.

    So as I said, the sound you hear when you open the door is IMO more than likely the brake boost pump building up pressure, same as it does in the Gen III Prius when the drivers door is opened.
     
    #8 Paradox, Oct 29, 2012
  9. bisco

    bisco cookie crumbler

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    you can get most of the info you need by typing key words into search and reading the pertinent threads that come up. there is a wealth of info and most questions have been asked many time sin many ways. all the best!
     
    #9 bisco, Oct 29, 2012
  10. brucepmiller

    brucepmiller Member

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    The service manager at Toyota told me the C had the coolant reservoir but after reading responses from Oldwolf and Paradox I would put my money on them.
     
    #10 brucepmiller, Oct 30, 2012
  11. dick_larimore

    dick_larimore Member

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    Your service manager needs to do some homework. The coolant reservoir disappeared with the Gen II Prius.
     
    #11 dick_larimore, Nov 1, 2012
    brucepmiller likes this.
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