Prius Noises

Discussion in 'Gen II Prius Technical Discussion' started by ifosso, Jan 9, 2007.

  1. ifosso

    ifosso Junior Member

    Jan 7, 2007
    Forks Township, PA
    Your Vehicle Year:
    2015 Prius
    Noticed two strange noises I can't figure out, though I'm sure their normal.

    After turning on car and hitting break while not moving I hear what sounds like an electric motor doing something behind the dash. Lasts about 3-5 seconds.

    When turning the car off and getting out, for 10-15 second I hear an electric motor run, I think I heard this before on my last car (Mazda 3).... almost sounds like something is getting wound up as the pitch changes right before it stops.

    Any ideas what these are/do?

    Thanks.. Ian
  2. Beryl Octet

    Beryl Octet New Member

    Aug 27, 2006
    Abingdon VA
    Your Vehicle Year:
    2005 Prius
    After you turn it off, it pumps the coolant into the thermos so that it's toasty when you are ready to drive it again next time. One of those things that makes you go "why doesn't every car do that?".

    The other noise you describe is a pump pumping up pressure in the brakes.

    Both of these are perfectly normal.
  3. member

    member New Member

    Oct 8, 2006
    These are listed in the manual.
  4. hdrygas

    hdrygas New Member

    May 22, 2004
    Olympia Wa
    Your Vehicle Year:
    2004 Prius
    Turn off the "tunes", roll up the windows and listen to the car. If you watch and break lightly up to a stop light you will hear MG2 as it generates electricity and slows the car. You can listen to ICE on and ICE off. The display will not always tell you this.
  5. orrink

    orrink New Member

    Feb 23, 2007
    I've noticed a weird sound from behind the dash also. Sounds like a very faint party noise maker, the kind you twist and spin in your hand. Am I nuts?

    <div class='quotetop'>QUOTE(Display Name @ Jan 10 2007, 09:57 PM) [snapback]373950[/snapback]</div>
  6. Bill Merchant

    Bill Merchant absit invidia

    May 3, 2005
    USA | Oregon | Portland area | 97004 |
    Your Vehicle Year:
    2007 Prius
    <div class='quotetop'>QUOTE(orrin kohon @ Mar 15 2007, 09:46 PM) [snapback]406586[/snapback]</div>
    You may be, but that is the brake accumulator pump. It pumps up pressure in a reservoir to give you hydraulic braking if you need it.

    There's an old saying that your car doesn't have to go, but it has to stop. The Prius has three braking systems, to make sure you can stop when you need to, plus ABS and VSC to give you better control in emergency stops.