Getting ready and doing research in preparation for the plug change on my 2006 with 73K miles, I read on several sites where the Motorcraft P/N SP507 plugs are the new-and-improved replacement for the old P/N PZT14F plugs that break off.

Based on this info, I headed down to Summit to pick up a set of the SP507's. After I got them home, I noticed that even though SP507 was printed on each individual box, when I pulled the plugs out of the boxes, they all had ONLY the PZT14F part # etched onto the plugs themselves. What am I missing here? Should I take these plugs back?

 

I would take them back and go pick up yourself a set of the champion plugs that are meant for our trucks. They are one piece and have gotten some great reviews here on the forums.

 

Yeah, I'm very familiar with the Champion 7989 plugs. I wanted to stay OEM, IF the SP507 plugs were new and improved, and I don't like the idea of paying a 50% premium for the Champions.

I've read where the SP507's are designed not to break (although they look just like the originals). I've also read that whenever a plug is upgraded, the original P/N (such as PZT14F in this case) never goes away, the "new" number is just added as a revision of sorts. Al markings on all boxes for these plugs are SP507 but like I said, the plugs themselves are etched PZT14F. Very confusing.

 

The new SP507's are supposed to be upgrated and stronger, the ones i just put in my truck say SP507 on the plug too! I would take those back and go to ford and get them.

 

Update: I've spent the day soaking, removing (attempting to anyway) and cursing these plugs. I also spent a lot of time on the phone with a very knowledgible parts guy at Ford.

Here's the deal: SP507 is IDENTICAL to the PZT14F plug. They are one in the same. SP507 is Motorcraft's part # while PZT14F is FORD's designation. When Ford issues a revision/upgrade to a part #, the old # ceases to be referenced. Example: My truck came with PZT1F plugs, NOT the 14F #. When Ford changed to the 14F's, they don't show a history of what "used to be" applicable to any particular model vehicle. Strangely enough, the PZT1F # is still in Ford's system, but it shows as applicable for the Explorer, Mountaineer and (I believe) the Mustang.

Sooo...the best that I can figure is that the SP507/PZT14F plug replaced the PZT1F plug for the 5.4 2004-2008 trucks.

I broke 5 out of 8 of the PZT1F plugs today. I've removed all but 2 using the Lisle tool and will pick back up where I left off in the morning. I'll be going back in with 14F's with anti-seize.

 

You need not have to change the spark plug till 100000 or 125000!!!!!

 

really?? do they perform well that long??

 

FWIW, mine were very noticeably worn. The ground straps were 70% gone and the tips were eroded back to where the gap was probably close to .070" as opposed to the specified .045". And that was with "only" 73K miles.

Mine's done now. Just got back from about a 40 minute test drive. Runs like a new truck!

 

Ford recommends my 05 gets a 60,000 mi change instead of 100,000 mi. due to the plug removal possibilities. My mechanic said he has changed about a dozen or do 05-08 F 150's and had only broken 2 plugs, but the extractor tool did it's job.
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You could leave them in till 100K.....but then your gunna break em for sure......

 

Where did you get 125 k from? The owners manual says 100 k but that's bunk. Guys are loosing performance, sputtering and missing at anywhere from 75k to 90k. Like Ryan5ohrl said, the longer there in there the harder it is to get them out.