Engine rattle at 3000 RPM and up

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by gregy1, Nov 10, 2025 at 7:43 PM.

  1. gregy1

    gregy1 Junior Member

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    Our 2007 with 245K miles started engine rattling on a long trip this weekend. Rattle started around 4500 RPM with a little subjective power loss as we went up hills on the interstate in CA and AZ. Rattle started to occur at lower engine speeds until now it's starting around 2800-3000 RPM. We did our best to keep under that engine speed but can't avoid pushing entirely. It does burn oil but we keep it topped off and it didn't burn any more this trip. We still have another 4-5 hour drive to get home and are routing to avoid hills. Will take it to a good independent mechanic when home, but would love to hear any insight before if someone can offer it. Thank you! -Greg
     
    #1 gregy1, Nov 10, 2025 at 7:43 PM
  2. Brian1954

    Brian1954 Senior Member

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    Are there any warning lights on the dashboard?

    My guess is broken piston skirt(s).
     
    #2 Brian1954, Nov 10, 2025 at 10:50 PM
  3. PriusCamper

    PriusCamper Senior Member

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    That's oddly specific... If true it's confirmed by finding metal in the motor oil?
     
    #3 PriusCamper, Nov 10, 2025 at 10:58 PM
  4. gregy1

    gregy1 Junior Member

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    Thanks. Broken piston skirts sounds pretty serious.

    No warning lights. Away from the car right now and didn't record the code, but DTC is for catalytic converter. Should have mentioned that, but it's been there for over a year without seeming impact.
     
    #4 gregy1, Nov 10, 2025 at 11:05 PM
  5. Tombukt2

    Tombukt2 Senior Member

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    It happens on 1NZ not real typical but if it's not out of balance usually water ingress related it is something to consider 8 would think something would be trying to get to oil drain particulates etc sometimes a thin gooseneck can reach in oil drain hole and sweep crap out.
     
    #5 Tombukt2, Nov 11, 2025 at 12:26 AM
  6. PriusCamper

    PriusCamper Senior Member

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    kinda like a magnetic pipe cleaner... I wonder if they make something like that?
     
    #6 PriusCamper, Nov 11, 2025 at 2:28 AM
  7. Tombukt2

    Tombukt2 Senior Member

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    Well you're trying to pull aluminum out the oil pan so a thin gooseneck chain you can bend into a J shape insert and drag bottom of pan . You could also just pour diesel fuel or kerosene down oil inlet . The in Rush of that lightweight liquid may push your pieces right over your drain plug a piston skirt will not fit drain hole but you ll see it
     
    #7 Tombukt2, Nov 11, 2025 at 2:08 PM
  8. gregy1

    gregy1 Junior Member

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    Thank you for the thoughts about piston skirts and pulling pieces out, if that's the issue. I've noted another characteristic of the rattling though. It doesn't increase in pitch (frequency) as the engine speed increases, but it does get louder (volume / amplitude) with the increasing speed. And if I push the engine, the sound starts at ever lower speeds. Like something is being shaken loose, but is not moving with the cam/crank shaft speeds. Taking it to a mechanic Friday morning but would love to hear more insights. Thanks! Greg
     
    #8 gregy1, Nov 13, 2025 at 1:44 AM
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