Hey guys. Got a problem here. Just bought a 2001 F150 Screw, 5.4 V8 less than a month ago. 67,000 miles. Truck started running like dung and a check of the codes showed a misfire on cylinder 8. So, I decided to replace all 8 plugs and coils. However, when I got to #8, which is the rearmost plug on the drivers side, I could not get it to break free. With a lot of pressure, I got it to "squeak" four or five times over the course of about an hour and a half working on it, before I decided to finally leave it alone and seek advice from someone who knows more about it than I do. The plug doesn't feel any looser than it was when I first started. Is the damn thing cross-threaded in there, possibly? Any suggestions on getting this thing out? What's the worst case scenario? I would really appreciate any advice!

 

If you have a flexable mirrior look down in there. My plug i think its 4 the farthest back on the passenger side. I guess coolant had gotten on to of the spark plug and froze it in there....took a lil bit but i got it out.

 

The worst case is it's corroded in the head and will break off or ruin the threads, that will require removing the head, and the only PROPER way is to pull the engine. I would suggest letting some lube set in there and soak for a while and then trying some more.

 

Update: Couldn't get the #8 plug out, so I sprayed some PB Blaster in the hole and let it soak overnight, tried it again the next evening and the spark plug came out! The threads on the old plug did not have any aluminum shavings or signs of the head being stripped, and the new plug seated and tightened just fine (with anti-seize, of course!). Apparently the old plug wasn't cross-threaded, just really tight. Thanks for the advice, joshmac!