my 01 5.4l threw a spark plug. driving down a city street and suddenly truck began sounding like it was uncorked. found the problem was a sparkplug came out of the socket. inspected the threads, no sign of a problem. bought a new plug and now i cannot get it to screw in. anyone have a suggestion?

 

Heli-coil.

Google it, bro. Many options.

http://www.google.com/search?hl=en&&...licoil&spell=1

 

This is what the dealerships use www.timesert.com

 

I would never use a helicoil on a spark plug hole.
Timesert or Full-Torque. Full torque is actually now Ford approved. http://www.locknstitch.com/FT%20pdf%...structions.pdf

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