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.Google+
Car Problem Reports
Ford Expedition TSB For Possible Ejection of Spark Plug From Cylinder Head
Ford Expedition Problem
Engines Affected: 4.6L V8, 5.4L V8
Average Mileage: 140,246 mi (11,800 mi - 230,000 mi)
Visitor, 2002 Ford Expedition, 5.4L V8, 11,800 mi
Number 5 blew while on vacation - setting in the lounge of a Ford dealership waiting for the verdict. This sucks! Ford should reapir this obvious factory defect free of charge.
Visitor, 2003 Ford Expedition, 5.4L V8, 200,000 mi
#4 plug went flying. Tried to re-tap and it went flying too. Poor design by Ford. Should have been a recall.
Visitor, 1999 Ford Expedition, 5.4L V8, 110,000 mi
I have had 3 blown spark plugs. Ever since I had the plugs changed at 100K. I know now that the auto shop likely overtightened the plugs during routine maintenance. BUT the fact that it happens at all is a design flaw that shoulld have been recalled.
Visitor, 2001 Ford Expedition, 4.6L V8, 163,000 mi
My spark plug was ejected, was told that condensation from AC line drips down into the deep socket where the spark plug is located and corrodes. Happens the most on last two plugs near the firewall on the passenger side of the engine. Paid local mechanic $216 to fix with Ford approved insert, works fine now.
Visitor, 1998 Ford Expedition, 5.4L V8
I have had spark plugs and coil pack replaced twice in a year. The second time it had to be rethreaded. Its starting to act up again.
Visitor, 2002 Ford Expedition, 5.4L V8, 185,432 mi
Spark plug came out of the head & broke the coil. got new spark plug & coil used a $400.00 tool called timesert reamed hole installed threader & installed timesert ran tool in timesert which flared into the head Installed new plug & coil now engine has 198000 miles on it & still is working great.
Visitor, 2003 Ford Expedition, 4.6L V8, 195,000 mi
# 3 plug popped out and destroyed the coil pack.
This is the second time and it destroyed the threads.
Visitor, 2002 Ford Expedition, 5.4L V8, 70,500 mi
#4 spark plug ejected. Heli coiled.
Visitor, 2000 Ford Expedition, 4.6L V8, 117,786 mi
Spark plug ejected from head.
Visitor, 1999 Ford Expedition, 5.4L V8, 162,000 mi
I NEED A NEW CYLINDER HEAD .. THEY JUST REPLACED MY EXHAUST MANIFOLDS BEFORE THIS HAPPENED