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Potential Solution to the Rough Start/Engine Rattle

Discussion in 'Gen 3 Prius Technical Discussion' started by FlyBoy2960, Feb 24, 2011.

  1. FlyBoy2960

    FlyBoy2960 New Member

    Joined:
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    Location:
    Allentown, PA
    Vehicle:
    2010 Prius
    Model:
    II
    I've been recently having the engine rattle/knock noise occasionally when I start the car. After my first oil change, I mentioned this to the dealer and demonstrated this to them while they documented the issue. I left my car at the dealership for investigation.

    The following day, my dealer said they called Toyota and created a case about this. Toyota responded saying they heard about this and the possible root cause is the Motor Mounts on the Prius. They will be sending parts (date is still unknown) to fix the issue. :rockon:

    I specifically asked if there is any damage to the engine and they said absolutely not and there is nothing wrong internally with the car. This also makes kinda sense because if I press the accelerator to the ground when it starts up, the knock doesn't appear. It also works if I put the car into D and drive away.

    For your information, I live in Eastern PA and purchased my 2010 Prius at a very large and popular Toyota dealer..oldest in the USA.
     
    1 person likes this.
  2. orenji

    orenji Senior Member

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    Any update on this 3 year old thread?
     
  3. TechGeek

    TechGeek New Member

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    orenji, are you seeing this on your Prius C also?? There's a thread on here about the TSB / possible fix for 2010 + Prius
     
  4. orenji

    orenji Senior Member

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    I have only experienced it once, and that was when I did not let the engine run through a full warm up cycle. Now I always allow the car to complete the warm up cycle, even if I am just moving it in my driveway. Its seems to have worked, as it has never happen again in 22,000 miles.
     
  5. TechGeek

    TechGeek New Member

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    Thanks.. My cousin in Canada with a C complained about a noise once on startup but hasn't worried about it as it hasn't happened again.. I was mostly just curious if this affected the C as well as the Prius - there aren't as many Cs out there as regular Prii so its possible that it affects the same percentage!
     
  6. David Beale

    David Beale Senior Member

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    The C isn't supposed to have this fault. In the hatchback the solution Toyota came up with was a redesigned exhaust manifold. All cars from about 2011 on should have this now. Any "problem vehicle" showing this fault should still be eligible for a warranty replacement of the manifold.
     
  7. bisco

    bisco cookie crumbler

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    Plug-in Base
    i don't think the manifold has proved to be foolproof. best insurance is not to start it up and shut it down cold.
     
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  8. Tommy Johnsen

    Tommy Johnsen Junior Member

    Joined:
    Apr 10, 2014
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    Location:
    Norway
    Vehicle:
    2010 Prius
    Model:
    III
    This is a well known issue in Norway. Two different solutions depending on the outside temperature.
    (Below and over freezing point)
    One is new improved intake manifold.
    The other is new improved injectors and new software.
    The motor mount is also making vibrations in some cases, but not very often..
     
  9. harry r

    harry r slowly turning green

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    III
    interesting to see this. when i first experienced it a couple of years ago in my 2010, the dealer had a solution. i brought it in for a redesigned manifold. not sure if it was intake or exhaust but it did not happen again until just a month ago. same rattle crap. all i did was put it into reverse and it went away. has not happened since but i am not convinced its a manifold issue. almost sounds like a timing issue. now that i am out of warranty, i hate to mention it to the dealer for fear of all kinds of remedies that they can charge for. otherwise she is running great at 34,000 miles
     
  10. Tommy Johnsen

    Tommy Johnsen Junior Member

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    Location:
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    Vehicle:
    2010 Prius
    Model:
    III
    Well.. The injectors are not cheap at all..
    I would not be to worried about this.
    It cost to much when you're out of warranty.
    The engine is shaking and rattling.
    Sounds horrible, but it has not been any destructions
    as a result of the issue. The root cause of this seems to
    be fuel related. I am not sure how to explain this in my
    bad english... But at least I can say that it's to much of it in the intake manifold and combustion chamber. Influences with the ignition timing, even tho no missfire
    is registered in the Data list..
    Open your hood and see if your engine is shaking
    next time it happens. First time I saw this, I was a bit choked and was a pretty fast runner to shut down the engine. But no worries... Nothing breaks. It's a Prius :)
     
  11. Stratman

    Stratman Member

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    Two
    If it's a 2010 with 34000 miles, according to my warrantee info you still have 2 years or 28000 miles on the drivetrain warrantee.
     
  12. AEROENGR

    AEROENGR Junior Member

    Joined:
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    Location:
    Connecticut
    Vehicle:
    2011 Prius
    Model:
    Two
    My 2013 Prius C2 with a total of 4512 miles made an engine noise on start-up a few days ago. The noise lasted for about 3 seconds after a cold start at 59F ambient temperature. It was a soft clanging sound at about 4 or 5 Hz and there was no engine vibration - the start was smooth. I had moved the car from the driveway to the garage the day before and shut down the engine after it had been running for about 15 or 20 seconds following a cold start. The noise occurred on the first start the next day. I also own a 2011 G3 and I am well aware that the liftback should not be shut down until the warmup cycle is completed. Since I had heard of no similar problems with the C, I shut the engine down without allowing it to complete the warmup cycle the day before. From now on, I will operate my C as I do the G3 - no engine shut-down until the warmup cycle is completed. My wife was with me in the C when the noise occurred. As slight as it was, she did ask me about it immediately!