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Intermittent knocking sound from engine, 2012 Prius v

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by lsp61, Oct 1, 2017.

  1. lsp61

    lsp61 Junior Member

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    My 2012 Prius v, which has done about 47,000 km, has intermittently developed a knocking sound when the IC engine is idle, or while driving at a low speed (under 30 km/h). The sound disappears on driving the car a few hundred meters and usually does not reoccur for several months. The appearance of the sound is not related to ambient temperature. It now occurred on 4 occasions in the last 12 months. The local Toyota dealership, who regularly service the car, have not been able to find any fault. I have never had any other problem with the car and consistently travel100 km on 5.0 to 5.5 litres.

    I was able to record the sound yesterday, but cannot post the video with the knocking sound, as I have not posted 4 messages yet. Hopefully I will be able to do so after 4 posts.

    I would appreciate any suggestions/pointers as to what the problem could be.
     
  2. bisco

    bisco cookie crumbler

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    that is going to be difficult to find. the engine is off, so you have ruled that out?
     
  3. lsp61

    lsp61 Junior Member

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    Thanks Bisco! The knocking occurs at low speeds, or when the car is stationary and the IC engine is idling. But as I said, it has only happened 4 times and the engine sounds fine in between these occasions. I live in Melbourne, Australia and the temperature ranges from 5-40 degrees C. The knocking sound has occurred during the cooler months, but it has not been particularly cold.
     
  4. bisco

    bisco cookie crumbler

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    the engine only idles when stationary in the warm up stages, yes?
     
  5. lsp61

    lsp61 Junior Member

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    That is correct!
     
  6. bisco

    bisco cookie crumbler

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    are you using the recommended engine oil?
     
  7. Sam Spade

    Sam Spade Senior Member

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    Are you feeling OK ?

    NO, it can "idle" at other times too.

    I'm not sure which models are affected but some Prius engines tend to knock at startup sometimes; particularly when they have been sitting unused for long periods, maybe only a few days, and it doesn't seem to be a problem.

    When we were shopping to replace my C, a salesman started up a new one......and it knocked LOUDLY for a LONG time. He was duly embarrassed.

    There are threads on here about it. If the search is working you might even be able to find them.
     
  8. lsp61

    lsp61 Junior Member

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    Yes I am. It is being serviced by the local Toyota dealer as per the log book.
     
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  9. lsp61

    lsp61 Junior Member

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  10. Sam Spade

    Sam Spade Senior Member

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    My first two sentences were directed at BISCO.......who I quoted.
     
  11. lsp61

    lsp61 Junior Member

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    Sorry, I was responding to bisco's question regarding engine oil.
     
  12. Tbkilb01

    Tbkilb01 Active Member

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    Search "engine rattle"
     
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  13. tvpierce

    tvpierce Senior Member

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  14. lsp61

    lsp61 Junior Member

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    Not sure why the audio was missing from that clip. Try this link https://goo.gl/q9FJJq
     
    #14 lsp61, Oct 3, 2017
    Last edited: Oct 3, 2017
  15. Air_Boss

    Air_Boss Senior Member

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    404. That’s an error.

    The requested URL was not found on this server. That’s all we know.
     
  16. lsp61

    lsp61 Junior Member

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    Sorry about that! The first link (https://photos.app.goo.gl/Zn1EJ869Si3XyhDC3) works. You have to play the video by clicking on the play button in the top right hand corner of the video. Until then the video appears as a GIF, without the audio.
     
  17. lsp61

    lsp61 Junior Member

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    You have to play the video (https://photos.app.goo.gl/Zn1EJ869Si3XyhDC3) by clicking on the play button in the top right hand corner of the video. Until then the video appears as a GIF, without the audio.
     
  18. Air_Boss

    Air_Boss Senior Member

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    Yep, that's a protracted case of "engine shake"/"engine chatter" at startup. Usually is a once-off or very infrequent, suggested to be due to unburned fuel remaining after shut-down.

    But this example sounds more like a Honda VTEC engine going into limp mode due to the oil passages of the VTEC solenoid being dirty.
     
  19. lsp61

    lsp61 Junior Member

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    Thanks for your assessment. Would appreciate your advice on what exactly I should get the service center to check/clean at the next scheduled service (in 30 days time)?
     
  20. bisco

    bisco cookie crumbler

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    do you ever start the car, move it a short distance, and shut it down with the engine running, such as moving it from the garage to the driveway or street, and etc?
     
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