I'm the guy that has been so proud of the fact that blown out spark plugs don't seem to happen to the DOHC engines and now it has happened to me

My 2000 Navigator just had the exact symptoms as those described in the TSB that was posted in another thread.
I had just arrived at home and was waiting for my son to move his car and my truck suddenly started to miss and tick. I backed up about 30 ft. and the miss got worse. I then pulled into the drive and the engine continued to miss and then a harsh knock developed which changed to a ticking again at idle, gas it a little and the knock reappeared. I got out the stethescope and gave a listen to the valve cover on the driver side and could hear noise at #6 so the next morning I did some research here and found this TSB info. In the meantime my son was looking at it while it was running as we thought an injector connector came off, again, and while he was feeling around in that area he got zapped pretty hard a couple of times and he then stopped messing around in there and told me about the experience. I then started taking the sparkplug cover off in preparation of removing the valve cover as I thought a cam follower or hydraulic lash adjuster had failed. When the plug cover was removed I found that #6 spark plug had ejected itself from the hole and the plug boot was worn through letting the spark go to the valve cover and shocking him hard, those are some powerful coils. We figure the ticking noise was the spark going to the valve cover and the knock was the sparkplug banging in the hole against the valve cover. I'll likely finish the thread repair tomorrow, if the rain stops and then know if my diagnosis is correct. I think it's kind of odd that a TSB for a newer engine pointed me in the right direction to find my problem and I followed it only because the symptoms described were almost identical to mine. My truck had been running great until this happened but the plug was black from carbon so there is no way of knowing how long it was just hanging there like that. Thank you for posting the TSB iggy.


Here's a link to the TSB; https://www.ford-trucks.com/tsb/full...hp?tsb=10-25-7

 

Typically, a plug that is not tightened down will not be black with carbon.

If the plug is tight, the plug gives up its heat to the cylinder head and water jacket. If its loose, the plug gets hot (i.e, no black carbon) since there is no good path for the plug heat to disipate.

Do you have a link to the specific TSB you are referring to?

 

I didn't take pics of the mess but believe me the plug was black from soot or carbon. I'll post pics of the repair in this thread as well as pics of the boot and coil after it is done in the next few days. In the mean time I'm stuck with driving my Mark VIII for a few days which is like sitting in a Go Kart in comparison to the Navigator. A real low rider and I love it.
The tool I bought for the repair was very reasonable in cost, just over $40.00. The mechanic that told me about it has done at least 10 Fords with the same tool with good results and no come backs.

 

Thank your lucky stars that it was cylinder 6 and not 4 or 8.

 

I already have.