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Loud thudding sound at idle

Discussion in 'Gen 2 Prius Technical Discussion' started by Banksy, Sep 16, 2020.

  1. Banksy

    Banksy Active Member

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    Was just driving down the high way and noticed a vibration/ hesitation when accelerating

    At idle there is a loud thudding sound that's going on.

    I don't have any codes pilling yet

    Seems to be coming from the drivers side.

    Any ideas?
     
  2. SFO

    SFO Senior Member

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    Any warning lights presented on the dash?
     
  3. Banksy

    Banksy Active Member

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    None

    When accelerating I can feel a lot of hesitation and a powerful vibration

    There is oil in this car just checked


    Also the engine seems to be wanting to shut down immediately at idle.

    Really confused here and concerned
     
  4. bisco

    bisco cookie crumbler

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    what exactly is 'idle' on a prius?
     
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  5. Banksy

    Banksy Active Member

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    P0300 P0303. P0304


    All misfires
     
  6. Banksy

    Banksy Active Member

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    Also just changed the oil like 500 miles ago.

    Has a new MAF


    Never did plugs on this car
     
  7. Banksy

    Banksy Active Member

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    That's pretty funny dude
     
  8. bisco

    bisco cookie crumbler

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    seriously, is that engine at idle, or engine off?
     
  9. Banksy

    Banksy Active Member

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    Idle

    It'll idle for a few seconds then shut off
     
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  10. bisco

    bisco cookie crumbler

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    maybe a loose heat shield or aero cover, can you get her on a lift?
     
  11. SFO

    SFO Senior Member

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    Depending on the SOC this could be normal.

    Check the plugs, you might have oil leaking into the wells from the valve cover. How many miles on the plugs and injectors?

    Do you have techstream up and running?
     
  12. Banksy

    Banksy Active Member

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    So I do have techstream I literally just got home.

    As for how old the plugs injectors and coils are I have absolutely no idea.

    I got this car at 250k did the trans axel fluid and HV battery and that's it. Knew I should have done plugs... Oh well.



    I have a set of plugs and coils on the way

    I am curious if this is the injectors

    Is there a way to test that in techstream?


    I'd like to see the resistance the injectors are putting out and see if it's in spec


    Is it likely this could be a timing or head gasket issue?

    I don't have access to a lift but this is definitely an ICE issue

    Cylinder 3 and four are misfires from what OBD is telling me on techstream. Only looked at it on techstream for a minute or so.

    Just find it very odd that two coils or plugs went out at the same time. Car probably needed these anyway but I got a feeling this is going to end up being something else
     
    #12 Banksy, Sep 16, 2020
    Last edited: Sep 16, 2020
  13. SFO

    SFO Senior Member

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    Be careful buying plugs online, as there have been numerous counterfeits reported.

    Did you inspect the plugs for carbon tracking or oil fouling already?

    You can use TS to look at the short and long fuel trims. Are you using top tier fuel or a PEA additive?
     
  14. Banksy

    Banksy Active Member

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    Got some NDK iridium plugs


    As for inspection of oil I haven't pulled the plugs yet. Or coils for that matter.

    However I probably will tomorrow. Might be the valve cover gasket you're right that's a pretty solid possibility.
     
  15. Banksy

    Banksy Active Member

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    Ok so didn't know that the plugs were so tiny my regular plug wrench can't get into the wells

    However I have one due in tomorrow

    I did pull the coils off cylinder at far left and far right am assuming one on the right is four.

    I didn't see any oil on either coil. However I did notice what looked like some white powder like residue on the end of the coil. I'm guessing this is corrosion.

    Like I said I'm not seeing any oil on these coils as of yet doesn't mean there isn't any on the plugs however I can't know that until I get a plug socket it

    Apparently 16mm is a really weird size and all my local parts stores don't have them
     
  16. SFO

    SFO Senior Member

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    Don't have a 5/8" spark plug socket handy?
     
  17. Banksy

    Banksy Active Member

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    No I don't my one I use for my other cars doesnt fit
     
  18. SFO

    SFO Senior Member

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    5/8" should be readily available just about anywhere, and way less expensive.
     
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  19. Banksy

    Banksy Active Member

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    Oh well when I called auto zone that's what they told me. I'll have one in tomorrow and go from there.
     
  20. dolj

    dolj Senior Member

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    The plugs are 5/8" and is what you need. One of the few things that metrication never converted. A 16mm plug socket will probably work but will be sloppy as 5/8" = 15.875mm, so just get the easily available 5/8" size.