Truck is all original. It's had some maintenance but otherwise no major parts replaced...

Shot my first plug out today. Blew my boot completely apart, the threads I am hoping are still in the head so the mechanic can easy out them and fix relatively inexpensive...

I luckily had a few new coil on plugs in the truck so the shop should be able to determine fairly quickly if the truck is salvageable or not.

I was about 300' from the mechanic shop when it blew so I limped it in and shut it down. About the best scenario one could ask I guess.

 

When was the last time the plugs were replaced?

 

Plugs were changed 20k miles ago. Motorcraft plugs.

 

Strikes me as improperly installed. Who did it?

 

That is the DAMNED UGLIEST PLUG I'VE EVER SEEN with only 20K miles on it.

It looks like the inner part of the plug came out of the seat/ground electrode portion.

What the heck, I didn't think Motorcraft plugs were two pieces like that, for the 2-valve heads?!?!?!?

I would run, not walk, to a mechanic who had nothing to do with the last plug change. Unless you did it yourself

 

When my rig spit a plug last year, it cost me about $250 for a Timesert repair. All things considered, not bad.

 

^This.
Unless it broke after hitting something on the way out, the threads of that plug may still be in the head.
You may get lucky and "easy out" the rest of the plug out of the head. I recommend buying or borrowing a video inspection scope to get a close look at the damage.
If the threads are bad, I recommend the Time Sert repair also. The kit is ~$410 USD new and includes 5 inserts. As someone else posted they paid $250 for the repair; it sounds to me like buying your own kit is the way to go especially if you plan to keep this vehicle. It took me less than an hour to do the Time Sert repair on spark plug hole #2 on my V10 and I had never done it before. That hour also included video scoping the work area and cleaning it at every step of the process.
Mine had previously been repaired with what I suspect was a Heli-coil. "It blew almost immediately" according to the previous owner.

 

^^^This^^^
Something ain't right there, never saw a blown plug that came apart like that.

 

Exactly, something ain't right.

 

Well, I thought the mechanic shop was open on Saturday and that was not the case.... I couldn't wait to see how bad it was because I really needed a ride for Monday. So I went up with my tools and got the truck running again. Looks as though that cylinder was a problem child before as it had already been sleeved.



I unscrewed what was left of the plug from the insert... Put antisieze on the plug threads and threaded a new plug into the insert/sleeve. I put loctite on the sleeve and put it back in the head. Plugged everything in and she started right up. $10 fix. I always had a slight miss at idle... It seems to be gone. So I think I fixed two birds with one stone.

 

That is indeed one ugly plug----would expect that to be original with 235K miles on it!

Not sure what LocTite you used for the sleeve but seems to me most of their products crystallize at 450F or something close----doesn't that negate using it as a thread locker in the head?

BTW glad you got your truck running again!

 

This was my thought also, but the Time Sert kit includes red "high strength" Loctite 266 and the instructions say to use it so I used it on mine too.

I am interested to know how well this repair lasts. Based on my understanding of how the Time Sert insert is installed, I would want a NEW insert installed instead of reusing the old one. The installer tool spreads out the new insert to set it into the head, and the one that was removed may be misshapen.

 

I'm certainly no Timesert expert, but I seem to recall the shop which repaired mine saying there are some teeth which get tapped into the head once installed to fully ensure the insert never backs out. Others on here can confirm or deny that statement.

 

No teeth on the Time Sert inserts supplied with my kit.
The insert is slightly beveled at the lower end. If you thread a plug into it before installation you will see that the plug does not fully thread into it. During installation of a Time Sert, there is a specific installer tool that is shaped in such a way as to assist in spreading out the insert to fill the newly tapped threads.
I researched it a bit before I bought the kit and I remember reading about one that does have teeth, maybe it was Lock-N-Stitch? I got the Time Sert kit because of all the good recommendations I saw for the Ford Triton spark plug kit specifically and because of outstanding reviews for all their other kits.

 

That insert doesn't look like the Time-Sert insert I used.
The Time-Sert insert is torqued in at 20 ft/lb with hi-temp Loctite on the threads.
One of the installation tools looks like a tap, but pushes that odd spot on the 2nd/3rd thread out into the new threads cut into the head for additional locking force.