Mikey44

Purchased an '07 GT/CS recently and it just turned 69k miles. As I normally do when buying a used car, I changed all the filters, air, fuel and cabin. Didn't change oil as it was changed just prior to my purchase. Then I read that the spark plugs should be changed every 30-60k miles and watched several videos about the 2-piece plug and how they are prone to breaking if they haven't been changed on a high-mileage car. Now, historically, I'm not a Ford guy, so this 2-piece plug stuff was new to me. Mopar and GM products have been my main rides since the early 60's, with the exception of one nice '41 Ford pickup street rod, but it did have a Chevy engine! Anyway, back to this spark plug deal. One of my friends is a Service Writer at the local Ford dealer, has been for years, so I asked him if there was a way to tell if the plugs in my car were original without removing them. He said Yup, just remove the coil pack and look at the top of the plug. If it's factory original, there will be a dab of either blue or yellow paint on the tip of the plug. If no paint, they are not original and have been replaced. OK, that's easy. Went home, let the engine cool down, and first thing I noticed was that all 8 coil packs had a dab of blue paint on them, which I assumed meant that they were original. Removed one, looked at the top of the plug, and no paint. Plug well was spotless, no dielectric grease, the boot was clean, no cracks and looked like new. So I put it back together, and looked at the remaining 7 and they were all the same.

So, after that little short story, is the Service Writer correct about the paint on the tip of an original plug, or does someone here on this forum know something different? In years past, I would have just gone ahead and replaced the plugs, but with these 2-piece plugs and the chance of breaking one, I'm not really wanting to if they have already been changed. And being 77, I'm not a hot-rodder these days, just a cruzer!

m05fastbackGT

There are plenty of threads submitted over the years which address the dreaded 2-piece design spark plug being prone to breakage.. Therefore, if you search the sub-forums by using the search function menu above, just type-in 2-piece spark plugs or 2-piece spark plug removal when the search box window displays.. You'll then come across a listing of threads which directly address the 2-piece design spark plugs..

Regarding your question about the paint on the tip of the spark plug? If you notice either a blue or yellow dab on the tip as your service writer says? then I would assume that he is in fact correct.

houtex

I dunno about the paint, and honestly I'm not a fan of trusting paint marks, but the coil boots are the one I've heard. If they're black they're two piece. If they're tan/brown, they're 1 piece. You'll still have to take them out to see, but it's one screw, a connector and then tug, no problem.

I'm not saying the paint thing is wrong, though. New info to me is all, never noticed it, and now I can't anyway, I've changed mine.

Oh, and ALL of this is assuming the original coil packs and spark plugs are installed, as if they aren't, then all this is out the window and you might need to just assume two piece until you get one out and verify. Which at the end is the only real way to know...? Of course, if they are two piece, and the one you're lookin' at happens to break, you'll need the kit and The Procedure to get that fixed, which I happen to have for ya here:
https://themustangsource.com/forums/...-plugs-522706/

Hope that helps, and good luck!

NC14GT

I just did a thread on my '07 GT/CS spark plugs with similar mileage. Check it out.

https://themustangsource.com/forums/...-plugs-549063/

Mikey44

Well, I think the photos of your original plugs answered my question about the dab of blue paint on an original plug that my service advisor told me about. Instead of being on the tip of the plug, the blue paint is clearly visible on the ceramic insulator just below the tip of your plugs. Going to recheck mine to see if I can see the paint without removing the plug.

m05fastbackGT

After reading over the OP's description, I assume he's more concerned as to whether his spark plugs are the original plugs which were never changed or were replaced by the previous owner.. His reason, I also assume is wanting to know for certain before deciding as to whether or not he should change them, which would also appear to be his reason behind if the blue or yellow paint on the spark plugs are the factory/original plugs.. The color of the coil boots alone won't determine whether the spark plugs are the originals, but rather if they're either the 2-piece design or the revised 1-piece design with the brown coil boots.

houtex

Ah. My brain missed that word. Dang. Thanks!

m05fastbackGT

For what it's worth, the OP also expressed some concern over the possibility of the spark plugs breaking after watching several videos of the 2-piece design spark plugs that weren't changed on high mileage 3v cars.. Although, I don't really consider 69k miles as high on the 4.6L 3v models, I would still nevertheless recommend checking the spark plugs every 3-5 years regardless of mileage by following the recommended Ford TSB extraction procedure faithfully and also apply a thin coat of high-temp nickel anti-seize to the ground electrode shields above the electrode straps, but do not apply any to the straps and especially not on the threads, as doing so will provide an inaccurate torque value.

Mikey44

Just finished removing all the coil packs again and, using a small dental mirror, looking at the ceramic insulator on each plug. No dab of paint, of any color, on any of 'em. So, I'm convinced that the plugs are not original and have been changed at some point, even though the coil packs are original. End of story!

tbear853

I have changed these type plugs on my '07 FX4 with 5.4-3valve ... exact same plug construction, only the heat range differed. I did it cool, used Kroil, etc ... I had 6 of the 8 come out well with patience, #2 came out leaving just the lower barrel and broken lower porcelain in the head. #8 though, the threaded body came out but it left the complete porcelain, conductor, and lower barrel stuck fast in the head.

The Lisle 65600 kit took care of #2 very easily, just follow the included instructions. #8 plug was something else, the instructions said to grab the top of the electrode and pull as you wiggle, it was in my truck and #8 was not so easy to get anything into to pull with, ... so I ordered a Lisle 65710 "porcelain puller" overnighted to me. It has a 4 jaw spring steel end that snaps over the top of the electrode, it's gets used with a tube already in the kit thus locking it on. It pulled the center electrode with porcelain out, then the barrel extractor finished the job. The #2 I used the pusher to push the broken lower porcelain into the lower part of the barrel, it will not be pushed out, it gives just enough room for the barrel extractor to get a grip.
The 65600 plus the 65710 makes a 65700 kit. Might be cheaper that way. When the porcelain pusher is used, it sets a limit on how far it pushes. The kit really works. Have air and a nozzle with 1/4" ID hose for blowing out cylinders. If you put the hose into the cylinder then pull the trigger on the blow nozzle, the air going in will come back out past the hose with any porcelain particles, so wear eye protection.

Really, the kit will all but guarantee no head removals.

The newer plugs have a slightly different look at lower barrel to threaded body and slightly different attachment of the ground electrode. The top of the plug also raises the seat for the coil spring thus applying more pressure in use. I do not dread a plug change on the Mustang as all 8 coils are in plain view and easily accessible ... not so on the truck where back plugs are way back under the firewall. I'm just 68, but hoping to be cruising still at 77.

m05fastbackGT

If you intend on holding onto your "07" GT/CS for an indefinite period of time? You're eventually going to need to change the spark plugs anyhow.. As mentioned in a previous post, if the spark plugs are checked/changed every 3-5 years, the risk of breakage is greatly reduced due from far less carbon build up around the electrode shields of the spark plugs which can cause them to seize up inside the heads..

After applying a thin coat of high-temp, nickel anti-seize to the electrode shields of the new spark plugs above the electrode straps, this will prevent carbon from building up around the electrode shields and also from seizing up inside the heads.. Once you apply the high-temp, nickel anti-seize as required, the risk of spark plugs seizing up inside the heads becomes very minimal, providing the spark plugs are removed carefully by following the Ford recommended TSB extraction procedure!