Strange gurgling sound from the vent grill under the windshield - please help to identify and fix

Discussion in 'Gen 2 Prius Technical Discussion' started by Norwegian, Oct 6, 2020.

  1. Norwegian

    Norwegian New Member

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    Hello folks!
    I got some strange sounds (watch the video) from the ventilation right under the windshield in my NHW20 (2006). A mix of something irregularly rotated or gurgling - I can’t understand. This is neither engine nor AC (I turned it off to record the video)


    What could it be? Some trash in the ventilation? (then how to pick it up from there) Dying fan (which one if it’s not a part of AC)? Any ideas?

    Thanks!

    Max
     
  2. bisco

    bisco cookie crumbler

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    Tough one.
    The fan is beneath the cabin filter, behind the glove box.

    Or, it could be a stuck vent door or even a bad pump
     
  3. fotomoto

    fotomoto Senior Member

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    Since the cabin fan is set to off, I'll suggest the HVAC door that controls air flow direction is malfunctioning. Put your head down near where the front passenger's feet would be and see if its louder down there. Second suggestion: CD player is malfunctioning.

    GOOD LUCK!
     
  4. Norwegian

    Norwegian New Member

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    Thanks for your suggestions folks! Will continue the investigation.

    Is this fan separate from HVAC? Seems like the one which produces my sounds is always on..

    Could you please provide more details on that piece? Is this "door" working like a fan? And is this "always on"?
     
  5. bisco

    bisco cookie crumbler

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    each air vent position on the hvac controls has a motorized door to open and close air to the windshield/dash vents/floor, as well as recirculate vs fresh air.

    most of them require dash removal to get access to. the service manual has the repair proceedures.
    they don't 'run' constantly like a fan, but when stuck, keep making a sound as the motor tries to move them.
     
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  6. mr_guy_mann

    mr_guy_mann Active Member

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    My first guess would be a fault in the CD player/ changer- does yours work? Maybe try locating and removing the fuse for the CD player.

    It could also be a air door in the HVAC, but usually when one of those goes bad it makes a sharp clicking or snapping sound. One way to narrow things down is to turn the blower on low, then change one thing at a time and see if it affects the noise. First temperature full cold then to full hot. Recirculate on then off. Lastly mode: dash vent to heater to defrost. If the noise doesn't change as you are manipulating the controls (and the airflow changes as you command it0 then your problem is not in the HVAC.
     
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  7. douglasjre

    douglasjre Active Member

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    The gerbils are trying to get out
     
  8. edthefox5

    edthefox5 Senior Member

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    Sounds like the hvac door. Mine does it to but not that bad. The noise is the loudest down on the floor by the gas pedal behind the big plastic cover under the radio.

    But talking about the front air dam water vent next time you change the spark plugs good time to clean that out. Just stick a hose down its 2 vents and flush it out. You can check it now by filling up that dam with a hose its vents out the back of both front wheels. Should have strong stream of water coming out behind both front wheels.

    It may have alot of debris in it especially if it lives outside and not garaged. Mine is garaged and still pretty funky in there.
     

    Attached Files:

    #8 edthefox5, Oct 7, 2020
    Last edited: Oct 7, 2020
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  9. ChapmanF

    ChapmanF Senior Member

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    I haven't listened to the 'streamable' link, but if it's a sound like it could be gerbils and the car is a Gen 2 (or Gen 1), try this thread on for size.
     
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  10. Norwegian

    Norwegian New Member

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    Hello folks!
    I was able to partially localize the issue. See the video:


    This sound disappears when I turn off foot vent. Does in confirm any of the suggestions above? Any ideas on how to fix it?
    Thanks in advance!
     
  11. douglasjre

    douglasjre Active Member

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    What was it
     
  12. ChapmanF

    ChapmanF Senior Member

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    I would suggest taking your video camera under the dash to watch what the air door linkages are doing. You could compare to the video attached in this post.
     
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  13. Norwegian

    Norwegian New Member

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    Finally, located and video-recorded the source of sounds - it's outlet selector actuator. I posted it to the corresponding thread to keep everything in one place for folks with similar issues.
    Now, time to understand how to fix it.. This actuator is not that easy to detach one.
     
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