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Hybrid Synergy Drive continous sound when idle

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jakov Glavina, Mar 16, 2019.

  1. Jakov Glavina

    Jakov Glavina Junior Member

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    Hello guys.

    So my dad has two Gen II Priuses, 2007 and 2009. He just recently bought the 2009 Prius and is concerned about the sound the 2009 Prius is making. When powering on the car, but not the engine (i.e. pressing power button without the brake depressed), the hybrid synergy drive converter starts making a continuous sound. It doesn't sound distressing or alarming, it's just there. Also there are no error codes and the car is in top notch shape. Again, at this time the engine is NOT running. The sample of the sound I'm talking about is recorded here:

    He claims that his 2007 Prius is not making this sound in the exact same conditions. So my question is: is this normal or something we should be concerned about?
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    You should not be concerned.

    The inverter often makes a high-pitched noise when the Prius is READY. The inverter coolant pump (located behind the driver's side headlight assembly) sounds like an aquarium pump when the Prius is IG-ON or READY.

    You only gave us 7 seconds of sound, but that sounds like the inverter coolant pump running.
     
    jerrymildred likes this.
  3. Jakov Glavina

    Jakov Glavina Junior Member

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    Thank you for the quick reply. Is there a particular reason why this doesn't happen on his 2007 Prius, though?
     
  4. dolj

    dolj Senior Member

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    It maybe that the inverter coolant pump is louder (noisier) on the 2009.

    At this stage, no need to worry.
     
    #4 dolj, Mar 16, 2019
    Last edited: Mar 17, 2019