I recently purchased a used f 150 Fx4 and i am really happy with it. I have always been a ford guy. My question is I have 104K miles on it and i wanted to change out the spark plugs. With all the research i have seen on this I am wondering if this is a smart move or a pandoras box about to be opened. The truck runs fine with a small idle rumble. Any input on this matter would be appreciated. I fancy myself a pretty good mechanic and feel i can do the job, but the horror stories i have read make me hesitant to take on this job. Any input about repair of broken plugs would be appreciated.

 

The breaking plug issues are with the 2004 and up. No issues with the 1997 to 2003's. I did mine a few months back. It's not too bad at all.

Mine had 100,000 miles, and were worn to over 80 thou gap. Wasn't much electrode left on a few of them.

 

Did you notice any difference after changing the plugs?

 

Here's an excellent write-up done by Otto. Any questions you have should be answered in here. https://www.f150forum.com/f72/97-03-...-change-93389/

 

I think I changed mine at 74K miles because I had a plug wire short out on the valve cover causing a misfire. Huge difference when all of that go changed.

 

Great write-up indeed. I have an occasional slight miss and I was dreading changing plugs..........not anymore. That job just moved to the front of the to do list for my 02.

 

Mine had 125k on it and truck started missing so I took it
To the shop an they said the two plugs in the back was stalk ones so I had all 8 changed and couldn't tell a difference besides my wallet was really thin when I left and it didn't miss

 

what is the new plug number for motocraft on a 4.6L V8?