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: 134,542 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, 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, 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
Visitor, 1997 Ford Expedition, 5.4L V8, 154,000 mi
Good grief this truck is a pain in the ass.spark plug blew out. Checked the Internet for how to .may option, would like the best. Help
Visitor, 2004 Ford Expedition, 4.6L V8, 120,000 mi
Spark plug was ejected out of cylinder head stripped the thread bought a special spark plug with a boot that hade coarse thread used hi temp two part putty from auto zone. Still going 10000 miles later, but now engine light is on!
Visitor, 2004 Ford Expedition, 4.6L V8, 220,000 mi
#5 cylinder spark plug blew out - was able to drive it to the shop this morning - waiting on repair estimate