2004 5.4 with 126,755 miles. ok folks, keys for success are as follows:

1. use techron concentrate for three(3) tankfuls
2. operate on cold engine (8 hours minimum idle time)
3. soak with SEAFOAM DEEP CREEP (8 hours minimum), before initial 1/4 turn cracking
4. when cracking 1/4 turn, listen and feel, screeching and popping are good things (indicates all parts of plug are moving as one unit)
5. walk away and soak another 8 hours (minimum), one application of SEAFOAM DEEP CREEP is all that is needed
6. grab your tools and just unscrew, and no, DON'T, i repeat, DON'T work plug back and forth. continuously turn counterclockwise

i know what you're thinking......THIS GUY'S FREAKIN' NUTS!!! well that's true, but here's the SECRET:

the OTC 6918 tool......follow instructions previously mentioned with the OTC 6918 in use and it will not fail you

p.s. reading countless posts and viewing videos 'til i was blue in the face, really gave me the confidence to attempt this much feared and dreaded task

 

No thanks,
I will stick with Kroil and a hand warm engine, and have them out in 30 minutes..

 

DIY - If it works for you, I celebrate with you no matter how you choose to do it,

 

Doing my 4.6 today. Much less stress. 97K is time.

Finished after 4 freaking hours! I don't know if I would have the patience to change plugs in a 5.4L! I certainly am understanding why the mechanics charge so much for F-150 spark plug changes now. Makes me miss my old '73 Chevy 350, and '92 F-150 300 I-6 for sure...

#3 cylinder plug was loose- a surprise. Thanks factory. That plug was filthy from the blow-by, and the boot had some mild heat damage, with light corrosion on the coil spring where it attaches to the top of the spark plug.