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Increasing engine noise/vibration/drone at higher RPM/accelertion 2011 versus 2014

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by cdherman, Jan 11, 2015.

  1. cdherman

    cdherman Junior Member

    Joined:
    Sep 25, 2011
    21
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    Location:
    Kansas City
    Vehicle:
    2011 Prius
    Model:
    Two
    Well Prii have always been a little "loud" under acceleration due to the CVT and small engine and minimal sound proofing, BUT

    We have 2 Priuses (Prii??), a 2011 with 41000 miles and a 2014 with 7k miles.

    My daughter got the 2011 to take to college. 1200 mile round trip so it made sense.

    She maintains that for sometime, the 2011 is making more of the droning/roaring sound that a Prius makes when accelerating briskly. I did not really believe, her, but over holiday break, I had the opportunity to drive both cars more, and she is right.

    The 2011 is clearly louder under acceleration. It also will develop a bit of a vibration at certain RPMs, even at very low RPM sometimes, when the economy bar is just beyond the electric mode.

    The noise differential between 2011 and 2014 is most apparent at cold temperatures, but it does not resolve completely even with both engines fully warmed up.

    This is NOT the cold startup rattle that is referenced in TSB 0012-10. I had that happen as well, and took it to a dealer, only to find out that the TSB 0012-10 has been withdrawn. Interestingly, they did find cylinder 1 misfire codes, though no CEL was showing. They could not reproduce, and sent me packing after extracting $99 from my wallet.

    However, at the dealer, they were showing me other TSBs, and there was one about increased engine noise. It recommended replacement of an engine mount. But I cannot find that TSB anywhere on the internet.

    Anyhow, does anyone know if this sort of noise increase is really the motor mount? Will something be damaged if we just live with it for now (daughter needs to leave for college)....

    Other ideas? I am pretty handy and I could get under the vehicle and drop the bottom shroud, and start it up on jacks and see if I can locate a source. But it seems to do it worse when under a load -- just reving it up does not result in the same degree of "loud"..... And its cold and wet under there right now.....

    Ideas? Opinions?
     
  2. cdherman

    cdherman Junior Member

    Joined:
    Sep 25, 2011
    21
    14
    0
    Location:
    Kansas City
    Vehicle:
    2011 Prius
    Model:
    Two
    Wow, 147 view and zero replies. Must mean I either have a rare problem or I described it wrong.

    In light of a couple other posts. I am bumping. I did find the TSB I alluded to. Pretty much describes my 2011 vehicle behavior. I need to check with a Toyo dealer to see if its a covered issue. Regardless, I think an upgraded motor mount is in order. Might cost some $$$ as I think its not a "drive train" warranty issue.....
     
  3. Christian_cool

    Christian_cool Junior Member

    Joined:
    Jun 7, 2014
    92
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    Location:
    Germany
    Vehicle:
    2010 Prius
    Model:
    III
    we also have 2 Prius in our family, one from 2010 as i have with 143.000 km. and a Prius 2012 Plug In with 70.000 km.
    Related to your post, your right. I have tried to drive my dads plugin with the engine and not electric and i feel its making less sound and vibration than mine if i make a full acceleration. The only thing i can explain is that the newer Prius models has a more and better redesignet Manifold and engine system, so it feels more comfortable as i experience.

    the second is: I had a problem for about some month ago with engine vibration when i was driving, after several times at the dealer i gave up since they couldn't find the problem. Later i found out that it was the manifold. Some small ventilation hold where blocked by sod. So i cleaned them and everything works fine again.

    Hope it helps you. :)

    Christian
     
  4. Siward

    Siward Active Member

    Joined:
    Aug 7, 2014
    296
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    10
    Location:
    Toronto
    Vehicle:
    2012 Prius
    Model:
    Three
    Not sure. Most engine noise posts I've seen pointed to the intake manifold.
     
    #4 Siward, Jan 15, 2015
    Last edited: Jan 15, 2015
  5. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    from what i've read, the motor mounts are a potential source of vibration. why not have them checked? good idea bumping btw, weekend posts get ignored a lot as pchat is not too chatty.
     
  6. xliderider

    xliderider Senior Member

    Joined:
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    Location:
    Honolulu, HI
    Vehicle:
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    Model:
    Three