2008 F250 5.4 140,000 miles

I was changing plugs back to Motorcraft got six of the eight done. The seventh one broke and the eighth may also be broke just haven't looked at it closely yet. I sheared off the 6-flat part of the spark plug with my socket. That piece came out with the entire center electrode. I took one of the spark plugs which were removed and on the workbench cut off the six flat nut to make up a sample of the piece that remains in the cylinder head. The sample piece is at the top of the picture. In the middle of the picture is the piece of broken spark plug that was removed. At the bottom of the picture is a full plate spark plug successfully removed. Turns out a 5/16 straight flute easy-out fits right in to the remaining spark plug piece. The easy out it's got a good bite on the piece but will not remove it so far.

My next plan is to apply hot and cold and some fashion to break the bond. I'm thinking using a torch and maybe dry ice but I'm not sure in what combination. Some logic would dictate heating the cylinder head and then chilling the spark plug piece. I could also heat the cylinder head with by running the engine on only seven cylinders ( assuming the eighth one still works ) but I think that's kind of risky.

Anybody got any tips for breaking loose this dang thing?

 

Warm it up...that means warm, not hot. Spray Kroil on it and walk away. Come back about 6 hours later and spray it again. Walk away. The next day use that punch since you say it has the best bite.

 

Can you please tell me how you ended up getting this out of the cylinder head. I have the same issue, same plugs. My issue is even more complex as not only the 5/8" nut flange sheared off but the porcelain electrode sheared off as well in there.

 

First one came out with the extractor shown.
Second one, I tried nut extractors on what was left of the rounded hex. No go. I used a 1/4" bosch diamond hole saw with hex shank on my drill to remove the porcelain. Some pieces fell in there but I was finally able to get extractors inserted. However it would not budge even after hot/cold, acetone/atf, etc. Tried spiral extractor and broke it off. Towed it to shop and $6k later my truck runs fine. Did get a new timing setup and AC compressor and did both head gaskets, and valve seals. some other stuff too. Mechanic suspects that the Champion plug rusted too much at the hex end. good luck; it is a lousy design. don't rush it

 

Thanks for the reply! I finally got the plug out. I drilled the porceline through with a 3/8" masonry bit. It had a 13" extension. I bought it at Home Depot. Then I used an Irwin EX6 extractor. I sprayed a bunch of PB Blaster in there. It would budge for a while. Then I started the car and let it heat up. Presto, I kept trying and finally it gave way. Now I need to find a good way to get the rest out without this issue arising again! Thanks much for posting!

 

so you were able to drill in to the porcelain? I have been told this was not possible. But I am getting desperate, hoping to avoid a $4-6k repair as a result of a spark plug change. Did you just continue to drill out the porcelain, or getting a hole in there allowed you to get the ez out in the hole?

 

Yes I was able to remove it with exactly I listed. I drilled out all the porcelain and the ez out. The Kroil spray was really the savior

 

I am fairly confident that with koil spray and an ez out that I can get the shell of the plug out. The concern is getting the porcelain out in order to get at that. It is definitely worth a $15 investment in a good bit to see if it will save me $4k. So I am going to try it. still have the risk of pieces going in to the cylinder, but will have to see.