Well I have an 05 XLT with the 3v 5.4 and its been running rough lately. Local shop took a look at it and said it needs new spark plugs. I bought the truck with 75k on it. Now it has 105k. Had new Bosch plugs put in at 85-90k. I'm alittle worried about them breaking off, but then again I don't think they have been in long enough to seize up, but just wanted to get someone else's opinion. Also they recommend I put in Autolites. Anyone running Autolites? How are they holding up? I was going to put in Champions but they said I should run Motorcraft or Autolite.

 

Motorcraft sp515....no others come close to these...

BTW....you sure you have Bosch plugs installed????

They don't even make them for the 5.4 3v....this might be your issue...

I wouldn't even go back to the shop who said they installed those Bosch plugs....

 

^^^ Yep, what he said

 

Are the sp515's one piece plugs?

My dad had the truck at the time. That's what he said they put in it.

The shop went out of business. I wonder why?

 

Yes (actually welded, but yes a 1 piece)

 

No, the SP-515 is 2-piece, just like the previous version (SP-507). Both
plugs have the 2-pieces welded together, and are not 1-piece like the Champion:

Motorcraft:




Champion:





However, I recommend the SP-515s over any other plug.

 

K thanks I'll ask them to put in the motorcrafts.
Beechkid you wouldn't happen to be a pilot would you?

 

STOP spreading bad info....the sp515 is still a two piece plug with a 'presumably' tighter crimp at the mid section.

 

Will they still seize up and break off or did they fix that?

 

The possibility still exists for breaking, however, follow the TSB by using NICKLE anti-sieze on just the shank portion, torque to 25 ft lb and replace at 60,000 miles. and ALWAYS have the Lisle removal tool in your back pocket.

With that..your probably of breakage will drop dramatically.