Need to rethread a plug hole from a blown plug | FordForumsOnline.com
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Need to rethread a plug hole from a blown plug

Discussion in 'Ford Crown Victoria' started by bradleyheathhays, Feb 12, 2019.

  1. bradleyheathhays

    bradleyheathhays Member

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    Bought an '11 Vic with the 4.6L back in June and a few months back I tried to change out the plugs. All came out ok except for cyl 4 which only cranked out 1/4 turn. Had a shop take it out and they said they had to redo the threads. I've seen videos where you can remove a stuck plug by drilling into it somehow, but because this was in the 4 position and hard to get to I'm guessing they just power cranked it out. Not sure but I'm guessing those threads are compromised now.


    Well, this past weekend that same plug blew out of cyl 4. Inspection reveals a coil and boot jammed up underneath the fuel rail and a plug that I fished out without any turning. When I go to install a new plug it just sits on top of the threads and turns without going in. So I guess what's happened is that the plug rotated most of the way out but when it got to the last couple threads the compression blew it out the rest of the way, and that it's just the top few threads in the hole that are damaged. Inspection of the plug reveals that most of the threads are intact except for the 2-3 that are closest to the element.


    So my question is...should I try to fix this myself or just take it to a shop? Some kind of tap tool would probably fix it, but since it's the beginning threads that are boogered it'd probably have to start from the inside of the cylinder. I really don't have a clue as to how to approach this.
  2. Dominick 1

    Dominick 1 Well-Known Member Respected Member

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    see if this helps
    https://www.fordforumsonline.com/threads/4-6l-3v-broken-spark-plug-removal-method.10793/
  3. Conway

    Conway Member

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    If you can get it drilled out (which woukd produce another problem of not getting the debris down in the engine) you could look into a Helicoil. Or if you manage to not get into the threads of the spark plug hole then maybe all u would need is a thread chaser
  4. Action

    Action Moderator Staff Member Respected Member

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    Interesting. I believe you have a 4.6 2 valve. Not an engine that commonly suffers from stripped spark plugs,
    Since it has been repaired once before head removal is likely at this point.

    If you are not familiar with this repair I would advise professional help.

    The link posted above is for broken spark plugs on 3 valve module engines built before 2007. I do have one of those engines and am very familiar with the two piece spark plugs that break.

    >>>>>>>>>>>>>>Action

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