Buzzing noise at starup 2005 Prius

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by denniswcr, Sep 25, 2010.

  1. denniswcr

    denniswcr New Member

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    I have a 2005 Prius with 57,500 miles on it. Some times (not all the time) I get a buzzing sound from under the hood at start up. This noise is a buzzing sound, not the usual whiring sound. This buzzing will continue until the ICE starts. It seems to happen more if the car has sat for a couple of days or the morning is cold. Once the buzzing has stopped, it stays stopped for the rest of the day. I do not think that it is the brake pump since it continues as the car backs out of the garage (on battery) and the brakes are off, but stops at ICE start a few seconds later. Could this be the inverter cooling pump? Thanks Dennis Edson
     
    #1 denniswcr, Sep 25, 2010
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The buzzing sound is most likely from the engine coolant heat recovery system pump. You should also frequently hear that sound upon engine shutdown as the pump will run if the CHRS canister needs to be filled with hot coolant.
     
    #2 Patrick Wong, Sep 25, 2010
  3. denniswcr

    denniswcr New Member

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    Thanks for the reply. I always had the sound of the pump at start up and shutdown, but it was more of a whirring/ pump running sound. This is a definite buzzing sound, almost liike an old fashioned klaxton horn but very quiet.

    Dennis
     
    #3 denniswcr, Sep 25, 2010
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I'm only aware of one pump that would run upon startup (and not during routine operation): the CHRS coolant pump. So if the noise in question is in addition to the noise produced by that pump, I have no idea where that might be from.
     
    #4 Patrick Wong, Sep 25, 2010
  5. salju6

    salju6 New Member

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    I just got this 2007 Prius and it has 180 k miles. This noise is like a doorbell bzuzerthat no one is answering. It wont stop. No lights on dash, car seems to run really well. It is coming from the area of the inverter. I videoed it on my i phone but I cant download it here. It is definitely coming from the shiny square box = inverter under the hood on drivers side. As I said it buzzes at regualr intervals driving, at a stop sign, when the car is off.
    Please tell me what it is and how to stop it.
    Thanks.
     
    #5 salju6, Jun 19, 2018
  6. edthefox5

    edthefox5 Senior Member

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    To the OP the inverter buzzes quite loudly when the ac is on. The ac compressor is electronic.
     
    #6 edthefox5, Jun 19, 2018
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