There is a technical service bulletin for the V8 engines regarding a possible problem with the spark plug being ejected from the cylinder head, damaging the threads in the spark plug hole. If the vehicle is under warranty, cylinder head replacement is recommended. If the vehicle is out of warranty, Ford authorized the use of a specific thread insert to repair the head.
Car Problem Reports
Ford F-250 TSB For Possible Ejection of Spark Plug From Cylinder Head
Ford F-250 Problem
Engines Affected: 5.4L V8, V8
Visitor, 1999 Ford F-250, 5.4L V8
my truck was running fine. pulled away from a stop light and all of a sudden a loud noise from under the hood and my truck started running very rough...took it to a repair shop and was told that a spark plug had been ejected from the head taking out an ignition coil with it.it cost me approximately 2700.00 to get repaired. ford would not pay for the repairs.i was told that it was my problem.