One or More Spark Plugs May be Ejectioned From the Cylinder Head on Ford Expedition

Problem Description and Possible Solution

The Ford Expedition has known issues with the V8 engine ejecting spark plugs. This will make a tapping or knocking noise, plus the engine will begin to misfire at all speeds. The check engine light will also illuminate.

The threads on the cylinder head are too short and soft, allowing pressure from combustion to overwhelm and destroy the threads. 

When the spark plug ejects, the cylinder head becomes damaged, necessitating repair of the spark plug port threads, or replacement of the cylinder head and cylinder head gasket. 

Ford has recommended a method of repair for the cylinder head that prevents the spark plug from ejecting under future use. Replacement of all spark plugs is not necessary, but an updated spark plug design can help prevent this from happening in the future. 

There is a technical service bulletin for the V8 engine.

Problem Data
RepairPal Verified
Average mileage: 153,682 (11,800–298,000)
Engines affected: 4.6L V8, 5.4L V8
9 model years affected: 1997, 1998, 1999, 2000, more2001, 2002, 2003, 2004, 2007
109 people reported this problem
Viewing 1 - 20 of 67 comments
I started my suv up nd heard a knocking sound I check to if the oil was low but it wasn't then I turn the car back on to see where the knocking coming to find out that one of the spark plugs pop out what do I do next.
spark plug blew out of engine destroying the coil with it. No threads left to put in new plug. just happened today. not sure how to fix
I have had 3 different plugs blow out and have had to replace all 3 coil packs. I have always done most of my mechanic work because I have mostly lived check to check. I am disabled now and don't have the money for DEALER recommended overpriced parts so I have had to use the cheapest auto store parts. Now the truck has been missing very bad. the OBD system says number 2 and 7 cylinders are misfiring. Both are previous Rethreads. Now after removing the plugs(they were loose) the rethread came out with the plug. the entire end of the plug and threads are melted. Obviously the steel threads heated and expanded and worked loose and I was getting ready to blow out the plugs again. Now I have to replace both heads. the repair at the dealer is more than the expedition is even worth now. I have been trying to sell it because I can no longer afford the gas after loosing my job due to disability. Now I am stuck with a truck I cant even sell for $1000. the list price for it just 13 years ago was over $33,000. I have been a ford person all my life UNTILL NOW!! I have bought an old 1990 Mercedes 4 door and am fixing it up do keep for a loooong time. Its a solid car with a great safety rating and is still a great car. I AM EMBARRASED TO BE AN AMERICAN THEESE DAYS. The giant corporations make all our stuff disposable and engineer it to fail so you have to keep buying MORE STUFF. Signed... EX- ford owner. and pissed off American...

was loose
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.
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.
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.
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.
# 3 plug popped out and destroyed the coil pack.
This is the second time and it destroyed the threads.
Pulled out of the alley and heard the pop and pfft pfft pfft limped home and backed into the garage. There is no excuse fir this. What dumba$$ thought it was smart to thread into aluminum without a stainless steel insert. I am a design engineer and know better. This is one way they short cut to save money. Ford Motor company knows better, they pay their folks that are material specialist and design engineering knows that you can't rely on steel bolting into aluminum, especially on replacement parts, items that WILL have to be removed and replaced more than once. BAD BAD BAD engineering and worse yet, only issuing a service bulletin and not offering to fix it if it happens? Come on. I thought you were a proud company, a MADE IN AMERICA company. Not a once and done, you bought it it is all on you now mentality. No customer loyalty from the manufacturer.
this is the 2nd time a plug has blown out on my expedition while i was going down the road. last time it was #2 this time #6
#4 plug went flying. Tried to re-tap and it went flying too. Poor design by Ford. Should have been a recall.
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.
Problem was with cylinder 3 spark plug was blown into bottom of the coil pack. This problem needs to be addressed by Ford. It is happening alot.
Heard a loud pop, and immediately started missing. Put in insert, new plug, coil, and boot. Hope it makes it another 120,000.
It just happened today. The engine blew off spark plug and coil. Got scared. Thought remaining parts of the plug could fall in engine. Went to autozone, bought a sparkplug and a new coil, replaced and now have my fingers crossed.