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Knocking Sound

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by ahmad ashfaq, Jul 1, 2015.

  1. ahmad ashfaq

    ahmad ashfaq Junior Member

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    Dear Folks,
    There is a knocking sound when reaching 2000 RPM , (2010 Prius III )
    Cleaned Throttle body.
    Spark Plugs changed
    Still the annoying sound is there .

    Any help will b appeciated .
     
  2. Beachbummm

    Beachbummm Senior Member

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    did you check your oil level?
     
  3. bisco

    bisco cookie crumbler

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    engine mounts?
     
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  4. Former Member 68813

    Former Member 68813 Senior Member

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  5. ahmad ashfaq

    ahmad ashfaq Junior Member

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  6. RogerHq

    RogerHq Junior Member

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    Does also have a knocking sound but only when accelerating and after approximately 30 seconds it disappears only to come back later. The sound is stronger when acceleration is stronger.This only happens when the engine is warm. Don't know if it comes from transaxle or from the combustion engine...
     
  7. Umar Ali

    Umar Ali Member

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    yesterday i heard the knocking at lower rpm when i was just kind of coasting in small street it was loud as something was striking at the bottom of car. i kind of reproduced it three to four times and it did produce. i have already cleaned the manifold from carbon before. i am about to change PCV valve today hopefully that will take care of issue.
     
  8. RogerHq

    RogerHq Junior Member

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    "cleared your manifold from carbon" ?
    That reminds me of a problem I had some months ago. That caused a replacement of the plastic cavity who is part of the air inlet to the combustion engine, it that what you are talking about Umar?
    I remember there was some carbon deposited on the inner cavity walls and the symptom semmed to be unstable ignition. The part is recycling exhaust fumes, that's where the carbon comes from I guess.
     
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  9. ahmad ashfaq

    ahmad ashfaq Junior Member

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    Yes The Oil Lever is all right .
     
  10. electrontechnik

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    I had the same thing and put a can of seafoam into the fuel tank (with 120ish miles to go to empty) and a can into the engine oil filler cap. Problem went away after the oil change. I've put 40ish thousand miles on it since then and no issue.
     
  11. Umar Ali

    Umar Ali Member

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    Yes exactly that plastic structure which connects to the engine and takes air from air intake pipe. It has bunch of carbon deposits in it. I used throttle body spray and carbon just melted out of it. I have also changed PCV valve successfully yesterday and now i have to see if it brings my MPG to normal. The engine vibration has reduced considerably after changing PCV Valve. But the knocking at light throttle i did hear again this morning. I dont know what that knocking at light throttle is related to?Oil level is good, only thing is coolant level is below the low level