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HELP!.... Spark plug Porcelain broke off

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Thomas Ziongas, Feb 10, 2014.

  1. Britprius

    Britprius Senior Member

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    The spark plug threads are in the cylinder head. Removal of this is fairly complex requiring disconnecting the timing chain and much more. The way I would approach the problem would be to turn the engine crankshaft by hand till the piston with the pieces on top was at the bottom of it's stroke. Then retrieve the pieces with a flexible pickup tool and vacuum tube. Checking with a camera to make sure everything is removed. This would possibly be a slow process, but would be faster and cheaper than dismantling.

    John (Britprius)
     
  2. Thomas Ziongas

    Thomas Ziongas Junior Member

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    Ok spoke with tech. He said he checked with bore scope. Got nothing. He couldn't find any evidence of scoring, or damage anywhere. Threads looked clean and valves were good. He used the stethoscope and sounded like it was coming from the bottom end of the engine maybe the fourth cylinder. Says the noise could be related to something completely different. Only option was to tear apart the engine. Our buy new one. I mentioned could it be rattling on the cat he said prob not....

    So I left with no fix to the solution. He says he would have seen damage if the porcelain fell in. I guess I vacuumed it all up.... but still left with this odd noise.

    Car drives fine. Annoying tick under acceleration. And as of right now fuel consumption looks bid lower. Haven't take driven it too much to notice.

    Idk what to do. Might get a second opinion...this is very frustrating.
     
  3. bisco

    bisco cookie crumbler

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    can you pick this sound up on a phone recording when you drive and post here? i really think you're becoming paranoid and would be better off ignoring it. especially the mpg's, your imagination is running wild. ommmmmmm...;)
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    My edits to exstudent's list above:

    1) remove the cylinder head (not just the valve cover)
    3) new cylinder head gasket
    4) replace cylinder head

    This is not a minor project. For example, 1) implies that the exhaust, inverter, fuel line, timing chain, and camshafts are removed first.

    The best way to learn from the OP's mistake is to resolve that you will:
    a) use the correct spark plug socket,
    b) keep the socket perfectly coaxial with the spark plug at all times when removing and installing the spark plug, and
    c) figure out that the spark plug porcelain has broken before fully unscrewing the spark plug from its threaded hole.

    Then you can vacuum out the hole without worrying about bits falling into the threaded hole.

    Another possibility would be to attach a small flexible hose to the vacuum hose, one small enough so that the flexible hose could be inserted into the threaded hole to improve the likelihood of vacuuming up whatever debris is present.

    It sounds like the OP's mechanic did a reasonable job looking for damage in the cylinder. However it appears that a leak down test was not performed.

    As previously suggested, I would say that the OP should leave the engine as-is, unless he notices a serious issue. The added noise should be disregarded for now; just turn the radio on, loud. :cool:

    One alternative is for the OP to have a leak down test performed, but that may not show damage such as a slightly bent valve stem. The most comprehensive test would be to spend ~$1K to have the cylinder head removed and inspected for damage - IMO the benefit of such a test is not worth its cost, unless a serious issue exists.
     
  5. uart

    uart Senior Member

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    Yeah sounds very frustrating, but I think you should at least consider the possibility the this noise was there all along but you just didn't notice it. Sometimes after an event like this, you're expecting problems and listening for problems and so you might well hear something that you just never noticed before (were never listening out for before). Human senses can be very fallible in this regard ,and a lot of engines do have some amount of "ticking" noise in any case.
     
  6. uart

    uart Senior Member

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    I'd also add that it's very hard to imagine any mechanism by which some of the porcelain entering in sparkplug well could effect the bottom end of the engine.
     
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  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Yes. Of course, a little belated now, but:

    As soon as you hear something, stop backing the plug out, start vacuuming. The deeply recessed, vertical wells are trouble.

    Isn't this a modern "innovation", ie: cars back when ('70's?) had plugs much more accessible.
     
  8. Britprius

    Britprius Senior Member

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    The problem arises with the advent of double overhead cams and 4 valves per cylinder. No where else to put the plug but in the middle of the 4 valves.

    John (Britprius)
     
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  9. Sina Drums fan

    Sina Drums fan Junior Member

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    When I changed my plugs at 232k I found the porcelain broken off #1 and 2. No telling how long ago that happened and it seems to run ok. IMG_20211221_132933446_HDR.jpg