Loud thunk sound, rear passenger side, going over bump, 2007 Prius

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jon85, Mar 17, 2023.

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  1. Jon85

    Jon85 New Member

    Joined:
    Mar 16, 2023
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    Location:
    Austin, TX
    Vehicle:
    2007 Prius
    Model:
    Four Touring
    Dear friends and threads,
    I did my online and Firestone mechanic due diligence, but no solution.
    Loud/sharp thunk sound when going over bumps in parking lot.
    I stripped the rear panels, removed back seat and removed spare tire, so no loose interior parts. Sat in the back while someone drove over the bumps and noticed the sound was coming from under the car near the rear right shock.
    Replaced all four shocks/struts, sound still persists while going over bump.
    Took it to Firestone, they put a strap over exhaust pipe, attached it to frame; sound still persists.
    Is there some body to frame bolt/bushing the needs to be tightened?
    Any help would be appreciated. Thanks
     
    #1 Jon85, Mar 17, 2023
  2. Fred_H

    Fred_H Misoversimplifier

    Joined:
    Apr 20, 2007
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    Location:
    Germany
    Vehicle:
    2007 Prius
    Model:
    Touring
    I once had a broken spring back there that klunked. It was broken at the very bottom, where it wasn't obvious.
    The only other things I can thunk of back there are the 12V battery, if it isn't secured properly, and the HV battery cooling fan and ducts.
     
    #2 Fred_H, Mar 19, 2023
  3. pasadena_commut

    pasadena_commut Senior Member

    Joined:
    May 2, 2019
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    Location:
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    Vehicle:
    2007 Prius
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    Is the hatch privacy screen firmly seated?

    When the hatch is down and latched is it at all free to move up and down? (Bad latch?)

    License plate holder? I once had a car with an annoying buzz in the back at certain speeds which turned out to be the license plate flapping. (Jamming a bit of foam under it fixed it.)

    It could be something up in the ceiling. When we scavenged an antenna base from the junkyard there were several components mounted between the headliner and the roof in that area. If one was loose it might make the sound you hear.

    Loose C pillar molding, or something loose inside the C pillar molding?

    You might need to pull everything out of the back and then have a person ride back there to locate the sound while you go over bumps. Just because you removed everything doesn't mean that there isn't some unexpected loose object bumping around.
     
    #3 pasadena_commut, Mar 20, 2023
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