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Mechanical noise under dash when warmed up

Discussion in 'Gen 2 Prius Technical Discussion' started by wanderso, Nov 13, 2018.

  1. wanderso

    wanderso Junior Member

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    Location:
    Portland
    Vehicle:
    2006 Prius
    Model:
    Base
    After our '06 Prius has been running for several minutes, we hear a sound under the dash. This sound exists even while parked in "ready" mode and the ICE is not running. Heat or AC is off.

    Can you take a listen to the audio file? Is this normal? This has been there since we purchased it this summer (2018)

    I am hopeful that the google link below will be accessible for all to listen. This site won't let me upload any sort of audio file. I've found that this will play fine in a web browser on PC or Mac but not on a smart phone. The noise is more noticed here than compared to when driving as I placed a recording device under the dash to pick up the sound better.


     
    #1 wanderso, Nov 13, 2018
    Last edited: Nov 13, 2018
  2. wanderso

    wanderso Junior Member

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    I should clarify that the sound isn't always there, but it is pretty common.
     
  3. bisco

    bisco cookie crumbler

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    maybe a bad servo motor or stuck vent flap in the hvac
     
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  4. wanderso

    wanderso Junior Member

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    Vehicle:
    2006 Prius
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    Does anyone else hear a noise like this from their dash? I’ve been in it before; not excited about another escapade into it as I cracked a vent cover last time (cheesy, brittle plastic)

    The HVAC is turned off and it still makes the noise but a good call as to if a flap is stuck. Could I be also hearing the inverter water pump and the sound transmitting into the car? Seems inside, though.


    2006 Prius Base
     
  5. 502_Prius

    502_Prius New Member

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    Location:
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    2007 Prius
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    Two
    Try to listen carefully under the hood, when you hear it, stop the car in a safe place, if you hear it near the driver side headlight it might be the HVAC coolant control valve just as Bisco said, it's really difficult to locate the sound because it's so subtle, but you might even get a check engine light, that's what happened to my '07 base, same noise, and I'm planning on doing the swap this week hopefully, part number for the '07 HVAC CCV is 16670-21010 and DTC P1121, it will make the noise even if you have the air heating/cooling off since it helps managing the hot coolant for fuel economy as well, greetings :)

     
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  6. wanderso

    wanderso Junior Member

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    Location:
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    Vehicle:
    2006 Prius
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    Base
    Thank you for the note suggesting that it might be the HVAC coolant control valve and for posting the youtube video. I'll take a listen up front the next time I am hearing it. I had the HVAC box open this weekend to change out the cabin air filter and clean the evaporative cooler with the foaming stuff. All the flaps that I could readily access in that location were functioning as expected.