Hitting noise coming from back seat area, when start the car. 23 prius

Discussion in 'Gen 5 Prius Care, Maintenance and Troubleshooting' started by priusasa, Aug 23, 2025.

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  1. VelvetFoot

    VelvetFoot Member

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    I wonder if you may have the rear seats folded down, any mods to the below deck foam, not using the luggage screen, etc.
    Anything that might enhance sound transmission.
     
    #21 VelvetFoot, Oct 2, 2025
  2. TGTGUUD

    TGTGUUD Member

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    My 24 LE does exactly the same thing since day one. Now it has 27K miles. I assumed it was normal...Let me know if it turns out to be something bad. Thanks.
     
    #22 TGTGUUD, Oct 10, 2025
  3. BiomedO1

    BiomedO1 Senior Member

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    That's part of the emission control system and Federally mandated warranty for 8 years or 100K miles; longer if your car is registered in a CARB state.

    I'd look at that TSB to see if they messed with that unit on the recall. Make sure this is properly and specifically documented; so if that part fails just outside warranty; you may be able to get it repaired for free.

    Good Luck......
     
    #23 BiomedO1, Oct 10, 2025
  4. priusasa

    priusasa Junior Member

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    So it was normal.

    I went to the place in the morning. Few hours later I went to check, they said they didn't find where the sound is coming from... Even though I told him exactly where it was coming. I showed him the part's picture.. Anyway, car had to stay 1 more day and they gave me some new generation prius for just 1 day. Which is very good service. Then I realized the Same sound is coming from 5k mileage prius... Slightly less. So I think it's normal.
     
    #24 priusasa, Oct 20, 2025 at 10:19 AM
  5. bisco

    bisco cookie crumbler

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    wow, that pounding sound is horrible. can't believe they all do that
     
    #25 bisco, Oct 20, 2025 at 2:38 PM
    PrimeDan likes this.
  6. TGTGUUD

    TGTGUUD Member

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    Thanks! Good to know. I think I saw the Car Care Nut saying the knocking noise is normal with newer hybrids, but can’t remember which video.
     
    #26 TGTGUUD, Oct 21, 2025 at 2:46 PM
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