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    seilerts Battery Curmudgeon

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    There is a service bulletin that potentially explains many of the reports of odd engine noise at startup, T-SB-0204-11. See attached.

    They state that abnormal vibration and droning can occur following a cold soak at low temperatures. An engine mount has been redesigned to address this. The good news is that, if it is an engine mount that is responsible for all the reports of abnormal startup, then there is not likely to be any long term mechanical consequences from these events.

    EDIT: A new service bulletin has been issued which involves replacement of the intake manifold. I have to wonder if tracking down the cold start knocking revealed that both the intake manifold and engine mount were defective parts.

    http://priuschat.com/forums/gen-iii...cking-startup-t-sb-0012-10-a.html#post1449615

    Attached Files:

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    The Critic Resident Critic

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    Great find. In the last thousand miles I have begun to notice an abnormal amount of engine vibration when the ICE powers up after a cold start (i.e. when leaving work late in the evening). In addition, during the first 1/2 mile or so, the ICE engagement is very noticeable and rough.
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    cyclopathic Senior Member

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    bummer, mine is not covered. Out of 60K warranty.
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    mainemanx Member

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    Ask; they might do it regardless.
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    wick1ert Senior Member

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    Awesome find!!

    Critic - Can you add this to the list of TSB's you'd compiled earlier that is in the Technical Discussion subforum as a sticky? That way they're all in a list still rather than all over the replies.
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    Pri4Us Junior Member

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    This 'solution' may cure one segment of the over 213 owner population reporting this anomaly here on PC; however, this TSB also states:

    "1. If customer complains of excessive vibration or abnormal humming through vehicle until engine warms up after an extensive cold soak (below 32ºF[0ºC]), replace the right rear engine mount with the updated part."

    I would venture to say that only a minority of those reporting this problem here had it occur at ambient temperatures that low. Most had it show up at well above freezing temperatures. Could it be this solution attempts to deal with the excessive ICE vibration and knocking by simply inserting a stiffer right rear motor mount? IOW, is this still an essentially unresolved engine problem?

    Secondly, will local service departments refuse to replace the motor mount if on the date the customer reported this anomaly the ambient temperatures never got anywhere near freezing?
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    spiderman wretched

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    As far as I am concerned that violent shaking that I experienced a couple of times at startup had nothing to do with an engine mount. I think they are drawing straws on this one.

    With that said, this would be a good T-SB to call in to get all my undercover clips replaced as many of them have been damaged from removing. :)

    Thanks for the link!
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    Mickduc New Member

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    Hmm, would Toyota Care extended warranty taken care of that?
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    wick1ert Senior Member

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    Good idea. I have a couple damaged, and my hope is that they would replace them. With my luck, they'll try to charge me for them!

    I have a tedency to agree with you on the grasping at straws. One would imagine that you would experience it with way more frequency if it was just an engine mount.
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    cyclopathic Senior Member

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    maybe; problem is we drive alot and keep cars until they die.

    All of Japanese cars we owned had developed problems well over 200,000mi mark.
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    Mendel Leisk Senior Member

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    Grasping at straws, LOL, as in: the drowning man grasped at a straw...
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    wick1ert Senior Member

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    Maybe they also drew straws.....as in, they grasped at a few, then drew to figure out which reason to give :)

    I saw that typo too, but was going to play nice and let it slide. Now, had I been at work and it was a co-worker, I would totally call them on it lol
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    Troyroy Member

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    I could not agree more......the shaking and noise that I had was NOT a bad motor mount.....Customers want Toyota to do something.....so they are replacing a motor mount.....doubt if this will solve the problem.
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    DetPrius Active Member

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    I agree this does not sound like a motor mount problem, so let's see how long until someone has the motor mount replaced, and STILL has the problem occur. I bet it happens.
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    frodoz737 The Mechanic

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    Since this is a T-SB, and has happened in the past, I called the Dealer. Said they would like a look see before ordering parts. This was issued only 6 days ago. Going in Monday to start the process. I still believe this to be a fuel issue, possibly pre-ignition, but will go with it on their nickle. Will also stop the single pump to throttle following Ready light when cold, which has worked so far. If this works fine, if not, then it is documented and I called them on it.

    Thanks for posting seilerts.
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    seilerts Battery Curmudgeon

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    The way I see, the more people that go in and have this done, without fruit, the more likely it is that they will dig in to the head/valve train/VVT and really figure out the problem. I agree, it is not likely to be the final solution for many people out there, but it is a simple, cheap thing to at least try.
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    ItsNotAboutTheMoney EditProfOptInfoCustomUser Title

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    I think I'll wait before having it done, on the "if they don't fix it they can't break it" principle.

    It seems a bit like the programmer's classic of identifying and fixing other bugs while trying to fix a different one.
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    cyclopathic Senior Member

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    Speaking of knocking.. Is it related to gas formula?

    Different states have different formula and ethanol %, some of it doesn't wanna burn well at low temps. CA/mid-west gas drove my bike nuts at higher elevations. But then you stop at different gas station and there is no problems, figure.
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    The Electric Me Go Speed Go!

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    Seems like there isn't a lot of faith among owners that this is the actual solution to the problem?

    It will be interesting to see if people have this done and the problem continues.

    Honestly? I don't know. But I have to think that if Toyota goes to the extent of redesigning the engine mount in the 2012's...and issuing a TSB concerning replacing older versions..that perhaps it IS fixing something....

    Its is considerable expense to redesign, and considerable expense to open yourself up for warranty replacement. I kind of doubt Toyota would do it frivolously.

    However, I will watch future posts with interest.
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    wick1ert Senior Member

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    I understand your POV on the topic and your logic does indeed make sense regarding Toyota just doing this for the heck of it.

    They may have not figured out what is causing the knocking to actually happen. Therefore, the mount will better absorb the effect being the fact that we see the engine rattling and making noise and want something done. It's possible that the new mount takes care of that part, or dampens it enough that it doesn't seem so bad. It is highly possible that by doing that they presume no (or less) long term damage will be done.

    It just seems that if a mounting bolt were really the problem, it wouldn't be specific to happening after a cold soak. Maybe someone has information to refute that. And what makes it specific to just being a cold soak? I've had spurts where my car sat for a few days, and started up just fine without any issue. I've had this event occur twice, and only once it was actually what they called a "cold soak", as the other time it didn't dip that cold.

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