Spark plug broke off

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by CharlesPrius, Jun 2, 2019.

  1. CharlesPrius

    CharlesPrius Member

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    Mechanic who last replaced the spark plugs in my 2010 (prev owner) over-torqued them and I'm left with a half-intact spark plug sticking out of my #1 cylinder. I changed the other 3, but #1 is still in there. I have no good ideas about how to get it out. As you see, it broke off just below the hex nut, so there IS some remaining metal sleeve on the top side to grab onto (now to find something to grab onto it?). Unfortunately some Porcelain sleeve (and bits) is also still present as it severed along with the wire (see pic). I've seen vids of guys using an ice pick to break up the porcelain to hollow out the bolt so that a #5 extractor can be used, but absent some simultaneous ninjalike shopvac skills to keep porcelain bits out of the engine, I'm very wary of this method. I'd rather try to extract it intact... or as intact as it is, anyway.

    Right now I'm using the Spray and Pray method. Sprayed some PBlaster & Prayed for a solution to avail itself by morning. I bought the longest, skinniest needlenose pliers HarborFreight had, but they're still too big. What to use? Universal socket? Extractor socket? Any ideas are appreciatd. Thanks. Now to bed.

    IMG_9047.JPG.jpeg IMG_9048.JPG.jpeg IMG_9038.JPG.jpeg
     
  2. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Can you get the broken off piece back on top of the remainder, and it locks in position? If so, load it up with jb weld, wait about 24 hours, then try again with a LOT of pressure as you turn? Maybe with an electric impact would be better.
     
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  3. The Critic

    The Critic Resident Critic

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    Lisle makes a spark plug removal tool for the Ford V8s. I do not have experience with the tool, but it may be worth investigating to see if it can be used in this application.

    Otherwise, I would remove the cylinder head and have a machine shop remove the plug for you.
     
  4. Dxta

    Dxta Senior Member

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    From the pictures here, it appears you got to removed the top cylinder head, and have a machine Shop take cars of the remaining.
     
  5. jerrymildred

    jerrymildred Senior Member

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    Hoo boy! I'd hope that the shop responsible would take ownership of their mistake, but it's not likely.

    Hard to reach. Harder to see. If the plug was tight enough to break, a screw extractor would probably break, too, but you can always try. I'm almost sure this is going to require removing the head. If it does miraculously come loose without removing the head, I'd blast it long and hard with compressed air to clear out any crumbs before unscrewing it.
     
  6. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    You might get it with that Lisle kit. From what I just read you use one tool to displace the ceramic and the other as a left-handed extractor bolt. Not sure if either tool is really long enough for the plug wells in a Prius.

    If you can't get it with that I think the head's coming off, sorry.

    I remain a huge fan of the plating on NGK plugs. Works wonders to prevent threads from seizing in the first place.
     
  7. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Torque value (from Repair Manual) for the stock plug is 15 ft/lb's, with clean/dry threads.

    Removing the head seems a real sand pounder. I would check with machine shop first, see what they propose.
     
    #7 Mendel Leisk, Jun 2, 2019
    Last edited: Jun 2, 2019
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  8. CharlesPrius

    CharlesPrius Member

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    Thanks for all the responses. Long term it looks like the head is coming off, I’ll call my mechanic when he opens on Monday. Short term, can I drive this thing on 3 Cylinders if disconnect the fuel injector? It’s my only car.
     
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  9. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Depends on what you mean by 'drive.' Depending on traffic conditions you can probably limp it to a nearby garage. It might need to be a middle-of-the-night-20mph-hazards-on kind of deal.

    It isn't going to run well enough to serve as safe transportation though. If you need to drive somewhere before the car gets fixed, activate plan b now.

    Remember, there is still a broken plug in there. The remaining fragment of the ceramic insulator could get dislodged, and if it drops in while you're trying to drive? Ugh.
     
  10. kc5dlo

    kc5dlo Active Member

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    Not an envious position your in for sure. Could the valve cover come off to offer a better shot at it?
     
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  11. Mendel Leisk

    Mendel Leisk Sand Pounder

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    The "spark plug tube" going down to the spark plug well remains in place after the valve cover is off. That said: I wonder how much disassemble is needed to remove that tube? Do the cams have to come off or no? There's info on install of the spark plug tube in the attachment in a new cylinder head (at page 15 of 20); it has an adhesive applied, then is tapped into place. There's no info on removal of the tube from an existing cylinder head though.
     
  12. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Removing the tube doesn't get you much space beyond the thickness of the tube wall and invites the mother of all oil leaks if it doesn't go back properly. Remember, it's still surrounded by valves and the meat of the head that holds the valves.

    Easier to pull the head.
     
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  13. Mendel Leisk

    Mendel Leisk Sand Pounder

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  14. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Still, number one option I think would be to phone a few machine shops, before diving in, pulling anything.

    OP may have it out by now...? He was up early, lol.
     
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  15. Usle

    Usle Member

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    I had a non firing plug in a gen2, it drove fine, 32mpg, which is why-how I found the bad plug, If it will start, it will drive...slowly.
    No lubrication if you disconnect the injector.
     
  16. Raytheeagle

    Raytheeagle Senior Member

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    Maybe he never went to bed:p.

    My son was in our room at 5:30 this morning:eek:.

    Today’s scout day at the Oakland coliseum :).

    Last year we watched a no hitter:

    Ever watch a no hitter live?

    Beat them ‘stros(y).
     
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  17. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Lousy video, but at least it attests that it is possible (with a little luck...) to back it out with a screw extractor:



    Memorable quote: "it saved my life". :)
     
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  18. Raytheeagle

    Raytheeagle Senior Member

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    In a nice accent to boot(y).
     
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  19. Usle

    Usle Member

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    He torqued his plug in at 200' lbs.
    He lucked out getting an easy-out into the broken plug.
    What could go wrong;)

    I like the op's idea of taking it to a mechanic, hey, a new head gasket.
     
  20. WilDavis

    WilDavis Senior Member

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    I have an identical extractor in my kit and that would have been my first thought! …but 200 lbs-ft!!!! (…Jesus Christ on crutches!) :eek:
     
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