As has been stated above, this was a poor design, the problem results because the threads of the spark plugs actually protrude into the combustion chamber and they are therefore exposed to all the heat and carbon buildup in the cylinder, something that no other spark plug threads have been exposed to.
I have never dealt with the aftermath of one of these breaking off in the head, but have seen it repaired. I have also seen others follow the Ford Service bulletin to a “T” and still break spark plugs. I also learn from others, so for me, here’s my method, but it only works in a shop as no one at home is likely to have the equipment:
Perform a MotorVac or some other fuel injection/carbon clean service. While this is being done remove all fasteners for the coils and any other item that will need to be removed for access (safely of course, since the engine is running). As soon as the carbon cleaning is done immediately remove the coils and items to gain access to the plugs. Using the appropriate 9/16" socket and extensions and a 3/8" impact gun on low setting remove the spark plugs. Once they start turning DO NOT stop turning them until they are out.
Alternately, using hand tools, be sure to do this on a hot engine, the carbon on the threads will be softer and give easier than a cold engine.
It does seem odd that Ford engineers wouldn’t have anticipated this problem given that the engine design has the threads protruding into the combustion chamber, when no other manufacturer has apparently done that. It seems like a no-brainer, maybe it is more complicated than what it appears though.
@GeorgeSanJose, look up a picture of a 5.4 Triton 3-valve spark plug and you’ll see that it looks different than any other spark plug. Like any new technology, the engineers simply can not anticipate every mode of failure. I’m sure they did testing to try to simulate 100,000 miles of operation, but I don’t know that they could generate carbon buildup on the spark plugs. Still, like you say…
Here is a picture of a plug similar to those in your 5.4L Expedition. I don’t think the threads protrude into the combustion chamber, but that long smaller diameter part goes through a tight area where it tends to get “coked up” by the combustion process. The coke is rock hard, and needs to be softened by whatever process, before removal.
@RobertGift , 100K is the expected mileage to change those plugs. I don’t think the ten year time frame has anything to do with your need to change them, unless it sits at idle a lot. I get the impression that you tend to blow the cobwebs out of it every now and then, but I don’t know if you spend much time at idle. Ford puts an hour meter on their newer P-71 police interceptor Crown Vics. They say one hour of idle is equal to about 33 miles of driving. I think that’s a bit high. Of course they want to sell service.
Thank you, MG. The 2008 Expedition idles little. When a hospital calls, I unplug the 200 Watt magnetic oil pan heater and pull it off with a rope I attached. Start and move the SUV (Super Unefficient Vehicle) into the driveway and get dressed. At the blood center leave it running to cool the engine for the few minutes it takes to load the blood boxes, then depart. Idle while unloading the blood boxes and switch off before entering the hospital.
So scared now that I plan on soaking the sparkplug threads for a day before attempting removal.
@ Robert Gift… Ford may say to replace plugs at 100k but THEY were the folks who created this dumb design. I don’t want them to cement themselves in my engine for another 50K miles. I’ll spend the time and money on new plugs now to prevent problems later.
I don't think the threads protrude into the combustion chamber, but that long smaller diameter part goes through a tight area where it tends to get "coked up" by the combustion process. The coke is rock hard, and needs to be softened by whatever process, before removal.
I used to have a co-worker that would get “coked up” on the weekends and have the same problem.
The stories we all heard Monday morning I tell you. He got fired when he failed a drug test and refused to go to rehab.
Robert ,
What is the production date of yours ?
After 10/09/2007 many of them had a different plug.
Look at the coil boots over the plug.
Are they black or brown ?
The old black boots cover the troublesome plugs. ( PZH14F - SP515 motorcraft )
The new brown boots go over an entirely different plug that does not have this issue. ( HJFS24FP - SP509 motorcraft ) A much skinnier plug that looks more like the normal plugs we’re used to.
My 08 Epedition has the brown boots and skinny plugs. No probles whatsoever changing them a month ago.
Sounds to me like its time to start designing “Mechanical Excellence” back into vehicles again,these things that some of these “Brainiacs” foist off on the unsuspecting public are shameful(there are certain manufacturers,I dont plan to ever own again)-Kevin
THANK YOU, KEN The boots over the plugs are BROWN! Spark plugs are SP509!
But our Ford dealer says it may still have the “irridium” spark plugs which get stuck.
Surprisingly, he suggests the Champion spark plugs over the Motorcraft sparkplugs.
Ford dealers say brown or black boots do not matter regarding spark plug breakage.
As Ken Green wrote, Brown boots take SP-509 sparkplugs and black boots SP515.
Some service technicians recommend not following Ford’s TSB.
They use an air gun and not do the carburator cleaner soak.
A parts store will sell an extractor kit and allow me to return it unused.
Ken, according to the VIN, this SUV was made December, 2007. Brown boots.
Thank you.
Stopped at an autoparts store.
2008 Expedition brown coil boots call for Motorcraft SP509.
They had ONE sparkplug. It has threads all the way down to almost the tip! “gap is not adjustible”.
Apparently I lucked out.
Thank you, all.