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Strange grinding sound in the morning.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Maxwell175, Nov 4, 2024.

  1. Maxwell175

    Maxwell175 Junior Member

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    Hello all,

    Recently I noticed a new grinding sound when I start my 2010 Prius in the morning. I can also hear it occasionally when the engine in running at idle. A year ago I already replaced the head gasket and this sound seems quite different from the head gasket rattle. It seems to mostly be coming not from the engine but more from the underside of the car. Here is a video of the noise. You can hear it clearly at 0:45 when I point the camera at the wheel well.



    Any ideas on what might be causing this?
     
    #1 Maxwell175, Nov 4, 2024
    Last edited: Nov 4, 2024
    Tombukt2 likes this.
  2. Tombukt2

    Tombukt2 Senior Member

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  3. Tombukt2

    Tombukt2 Senior Member

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    I truly wish you luck with that my 2013 Persona with an engine change it 230 or $40,000 for the head gasket problem I have the same noise I've just given up on looking for it The car is being parted out or getting ready to be It's unbelievable I have new EGR valve everything is cleaned on the replacement engine everything flows great looks good in TIS but I have almost this exact same rattle noise scraping the whole nine I don't see anything that's been left off or unapart the guy that did the change doesn't all the time and all kinds of cars He's even baffled He is not taking it back apart he doesn't believe there's anything not together correctly and the thing ran good for about 65 days after the change and then all of a sudden this Rattel scraping nonsense started up again
     
  4. rjparker

    rjparker Tu Humilde Sirviente

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    A little more detail would help.

    If it’s still there in Ready with the engine not running I would think Inverter pump or AC compressor. Possibly a radiator fan if the AC is on.

    The engine water pump shuts off with the engine.
     
  5. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    What's the miles? Are you first owner? If not, when did you acquire it? Was the EGR system fully cleaned, including intake manifold.

    (Quickly looked through previous threads you've got on this car, not exhaustively, didn't see mention of the above.)
     
    #5 Mendel Leisk, Nov 4, 2024
    Last edited: Nov 4, 2024
  6. Maxwell175

    Maxwell175 Junior Member

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    This video is just turning the car fully on first thing in the morning. The ready light is on. The sound happens only when the engine is on low RPM.

    My family has owned the car from the beginning. It is at 202k
     
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  7. rjparker

    rjparker Tu Humilde Sirviente

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    Check what it is does in Ready with the engine off
     
  8. Maxwell175

    Maxwell175 Junior Member

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    The noise only happens when the engine is on and at a low RPM.
     
    #8 Maxwell175, Nov 4, 2024
    Last edited: Nov 4, 2024
  9. rjparker

    rjparker Tu Humilde Sirviente

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    Then it could be the water pump or a timing chain guide problem.
     
  10. Maxwell175

    Maxwell175 Junior Member

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    The water pump was replaced when I replaced the head gasket last year (I know this doesn't eliminate it but makes me hesitant to go right to that). What's interesting is that the sound is happening all throughout the video, but it can't even be heard from the side of the popped hood. It's only audible when listening from the bottom/wheel well. I even brought my phone closer to the side of the engine that has the timing chain and still nothing. Is there anything that could be going on under the engine compartment?
     
  11. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    Which wheel well do you end up at? I’m guessing drivers side. If so, maybe inverter or it’s coolant pump related?
     
  12. rjparker

    rjparker Tu Humilde Sirviente

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    Water pump if counterfeit or aftermarket

    IMG_6624.jpeg