Wow that is crazy. What causes the the piston to blow the spark plug out?? My mom has a 5.4L Expi in her driveway right now.

I'm home from school in vegas right now but as soon as I left school, it snowed for two strait days and one day was down at -10. Good thing I left when I did.

 

The 5.4 is notorious for this problem, it blows the plugs out like the factory thread serts are junk.

 

You mean the factory casting's are junk...

 

Mostly on the earlier models, that only had about 4 threads in the head for the spark plug. I cant remember what the break point was, but eventually Ford improved the design by threading the full bore.

 

At least they circled the main problem and made it an emblem!!!