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Loud noise from A/C compressor - is this normal?

Discussion in 'Gen 3 Prius Main Forum' started by famoustale, Jun 20, 2020.

  1. famoustale

    famoustale Junior Member

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    Hey guys, I noticed this today and it's pretty loud.



    Only when A/C is on.

    Is this normal?
     
  2. AzusaPrius

    AzusaPrius Senior Member

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  3. Johnny Cakes

    Johnny Cakes Senior Member

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    I disagree with AzusaPrius.

    I think its the a/c compressor. The gas engine does not run continuously, so a compressor that can run on its own is needed. That's the sound it makes. There are quite a few threads on this.

    Very normal.
     
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  4. gliderman

    gliderman Active Member

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    I dont know if it is normal, but my 2010 IV does it too. And the air is cold.
     
  5. BZzap!

    BZzap! Senior Member

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    Standing in front of the car with the hood open, the A/C compressor can be quite noticeable. It’s pretty much normal from what I can hear. Inside the vehicle with the windows closed and the air conditioning going you’d be none the wiser.
     
  6. bisco

    bisco cookie crumbler

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    mine has always made a loud buzzing noise, the higher the fan speed. inside the car with windows up, hardly noticeable
     
  7. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    AFAIK these eccentric scroll type compressors make a buzz/whine suite that nobody at all can love.
     
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  8. AzusaPrius

    AzusaPrius Senior Member

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    I guess that is why in the OBD2 Carista app, you can quiet down the A/C compressor.

    Posted via the PriusChat mobile app.
     
  9. Grit

    Grit Senior Member

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    I love this sound, it tells me my ac compressor is working, and know troubleshoot else where if no cold air is throwing.
     
  10. Johnny Cakes

    Johnny Cakes Senior Member

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    That's not exactly correct. That option has nothing to do with directly changing the sound of the compressor or inherently "quieting down the compressor." It merely changes the base speed of the compressor which has an indirect effect of the noise created.[/QUOTE]
     
  11. AzusaPrius

    AzusaPrius Senior Member

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    [/QUOTE]But it does quiet it down right?
    Yea, it even says so in the app when I did it.

    Posted via the PriusChat mobile app.
     
  12. AzusaPrius

    AzusaPrius Senior Member

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    Just wanted to show you that you can quiet down the sound of the ac compressor. Screenshot_2020-06-29-10-16-35.jpeg

    Posted via the PriusChat mobile app.
     
  13. Grit

    Grit Senior Member

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    Not all features of larista can be applied or modified to turd gen prius. If that one does work, your HV battery will be sobbing during hot ambient temps.

    Disclaimer- this reply may not apply in all situations.
     
  14. AzusaPrius

    AzusaPrius Senior Member

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    The app Carista scans the car and only offers options that are available to your car so yes this option works with Gen 3 and it does not do anything as cooling less it just quiets the compressor.

    Posted via the PriusChat mobile app.
     
  15. Johnny Cakes

    Johnny Cakes Senior Member

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    It just makes the compressor run slower. An effect of that is that less noise is generated. And the direct effect is less output.

    The compressor is driven by an electric motor and runs at a constant RPM. This setting just changes the base RPMs at which the compressor runs.

    So comparing apples for apples at a constant RPM, it doesn't do anything to quiet the compressor itself.
     
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  16. BZzap!

    BZzap! Senior Member

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    Remember, there are always trade offs. Tweeking the software to run the compressor at a speeds out of it's design parameters will likely contribute to premature failure. Under high load conditions thermal dynamics play a large factor in component life expectancy. If it ain’t broke, don’t fix it!
     
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  17. Grit

    Grit Senior Member

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    Take a video of before and after, we ll be the sound judge.
     
  18. AzusaPrius

    AzusaPrius Senior Member

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    Not gonna do that I knew when I selected it when I bought the Carista that it did in fact make the compressor quiet. You guys want to see what the app can do then purchase it and do it yourself.

    Posted via the PriusChat mobile app.