It can happen on the 4.6, just not as likely

97 4.6 had 4 threads, and 99 4.6 up have 6
Im not 100% sure on the number of threads on the 5.4 but there is no way they had only 2 threads, which would be "half of the 97 4.6"

 

Sorry to say man, but you got hosed.....I just purchased a 97 E 250 cargo van with the 5.4...It had a blown plug, so I got a real good deal on it....I went to napa auto parts, got the threaded insert and new spark kit with shorter coil boot for 60 bucks, and put it in myself in about 10 minutes...fixed...idles and runs good as new....

 

1997 4.6L and had a shop tune it up. About 10,000 miles later, it blew the right rear plug, #4. I unplugged the injector and drove it home, approx. 5 miles. The plug apparantly backed out and it only turned in 4 complete turns. I torqued it down and pulled a couple more to check. All seemed okay but all only turned in 4 turns as well. I am assuming this one too has the 4 threads per plug hole. The truck has a total of 150,000 miles on it with 60,000 miles on double platinums. The hard to reach #4 probably was not tightened enough. No problem since then.

 

My 2008 F150 4.6L blew out the number 3 plug on the passenger side. 85k miles on the engine. The repair shop used the more expensive method of repair which is a steel boss type insert. I had them clean the injectors & intake, flush the coolant and transmission and replace the fuel filter. Now my engine has a loud ticking noise coming from the same area. The ticking is most noticable at idle and is steady except it stops occassionally for a second or two. The engine runs great. I had an oil change a couple hundred miles before the spark plug incident and I change the oil every 5k. I am taking my truck to the dealer on Monday but have had bad experience with this dealer in the past. Any ideas out there?

Thanks.

 

The only reliable insert is Timesert.

 

probably about to pop it out again...



but then again, a shop that won't properly install a simple spark plug probably didn't install a time cert either