Ford 6.8 spark plug blowout?

Engine has 220k miles.  Replaced all 10 plugs and coils earlier this year because I had a misfire and didn't feel like the dealing with "which one is it" for 10 coils.  We haven't been driving it much this year because of high gas prices, so there might be 3k miles on it since I changed the plugs.  So now, to the story of the failure.

Drove it about 50 miles to Winston Salem for a baseball game.  Noticed a ticking noise while driving it, very minimal, so I assumed it was belt drive since we have not been driving it much.  While driving home, we were about 10 miles down the road and heard a pop followed by what sounded like an exhaust leak.  I pulled off at a gas station and investigated.  #10 coil was pushed up and broke the body to the bolt that holds the coil in place.  Pulled it out and found the end of the plug smashed in but threads reasonably intact.  I disconnected the coil and injector and limped the van home the rest of the way.  

So, a couple of questions.  Did I possibly cause any damage by pulling the plug and driving 50 miles with 9 cyl. and an air pump?  With the thread blowout, wouldn't I expect to see some of the threads from the head on the plug?  Can the time-sert repair be done with the engine in and not cause problems to the engine due to drilling and tapping the head?

I am tempted to just throw another plug in it (if it will thread) and just ride on.  If not, I will be looking for a shop that has done the time-sert repair to fix it for me.  

Disclaimer:  While I've done a lot of reading on the subject since I, too, have a 6.8L mod engine, I have not gone through the process on my own.  That said, you shouldn't have done any damage driving with the coil unplugged.  Although, I shudder to think what it could have sucked in through the open port there....

It's unlikely that you'll be able to thread a new plug in.  And even if you can, the problem is caused by too few threads in the head for the plug to engage and now you have even fewer.  The Timesert insert kit is the way to go and can be done in the truck.  Of course it's #10 and all the way in the hardest part to get to, but what else would you expect, right?  Might need a right-angle drill for the job. 

I'm sure you know this now, but that ticking sound was the plug coming loose.  Conventional internet wisdom - if there's such a thing - is that the problem can be solved by over-torquing the plugs.  I think the FSM calls for something like 15 ft-lbs but I go to 25 or 30.

Try threading in a new plug.  If it torques up, you didn't tighten it enough the first time.  If it is stripped, you torqued it too much last time.

Yeah. Bad design.  Repaired by re-designing it badly so the plugs no longer come out at all.  Yay, Ford.

Dorman HELP! repair kit and done. Puts later long body plug in the place of the stripped one with an adapter that's shaped like a oversize drain plug. 'Hood for sure but universally successful without making the engine run worse than every other old modular ford. 

The threads are probably stripped, but it is relatively easy to fix as things go.  Have done a lot of blown out plugs in V10 vans.

I would not say it is a bad design, it works great on iron heads, where Ford used this setup for decades.  It did not translate well to aluminum heads.

Thanks for the advice everyone!  I should have mentioned this is an E350, so #10 is the easiest plug to get to on the whole engine.  Plan to get a couple of plugs and try to see if it will thread in.  If it does, hooray.  If it doesn't, then I'm sending it out to a shop.  

I've done it on a 5.4, but it should be the same.  By far the hardest part was access, so if it's easy to reach don't be nervous to DIY.  I bought a kit at Autozone for like $15 and had it done in about 30 minutes being slow and careful.  I just loaded up the reamer/tap flutes with grease to try to capture all the aluminum shavings.  I didn't use any power tools.

Pete. (l33t FS) said:

I would not say it is a bad design, it works great on iron heads, where Ford used this setup for decades.  It did not translate well to aluminum heads.

One could suggest that any engineer who takes a design, and recreates it out of aluminum without changing stuff, has created a bad design.

In reply to Streetwiseguy :

Or he has not created anything.