• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Need to rethread a plug hole from a blown plug

bradleyheathhays

NAXJA Forum User
Location
Lexington, KY
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.
 
Does this have the later 12mm spark plugs? Most of the Triton kits are for the early 2v engines that commonly blew out plugs. You may be able to find an insert kit for a 12mm that would allow you to tap to a bigger size and then install the insert. It can be some work but if it doesn't work you'll be looking at a new head. If if the shop just ran a tap thru to get you going it's not really they're fault. Not much they can do to get that plug out without extensive work.
 
Back
Top