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After 15 years & 62,000 miles I finally replaced the spark plugs
My mechanic carefully removed my Shaker (which involved quite a bit) and replaced my original spark plugs. He said it was time (despite the mostly highway miles) and none of them broke off. He has experienced this before, and was prepared for it, but no problems. They were replaced with the same Ford Motorcraft Platinum plugs so I should be good to go for another long stretch.
I enclosed some photos. It's about what I would expect and definitely time for 'fresh'.
Just makin' sure... nickel anti-seize on the sheaths, right? They'll come out smoove as butter next time, in 15 years, no worries about stickage/breaking.
My mechanic carefully removed my Shaker (which involved quite a bit) and replaced my original spark plugs. He said it was time (despite the mostly highway miles) and none of them broke off. He has experienced this before, and was prepared for it, but no problems. They were replaced with the same Ford Motorcraft Platinum plugs so I should be good to go for another long stretch.
I enclosed some photos. It's about what I would expect and definitely time for 'fresh'.
Consider yourself as very fortunate that none broke.. Hope your mechanic also applied a thin coat of high-temp/nickel anti-seize to the ground electrode shields as well, as the anti-seize prevents carbon from building up between the electrode shields and heads which causes them to seize up and break.
Originally Posted by Paris MkVI
Yup, the original plugs don't owe you anything! Glad they all came out without breaking.
If Ford had designed a traditional 12mm one-piece design for the 2005-early 2008 3v models from the very beginning? there would had never been a breakage issue, to begin with.. Ford finally wised up by revising the spark plug design for all 2008 3v models built after November 2007 back to the traditional 12mm one-piece along with revising the heads.
Originally Posted by houtex
Just makin' sure... nickel anti-seize on the sheaths, right? They'll come out smoove as butter next time, in 15 years, no worries about stickage/breaking.
I sure wouldn't risk waiting 15 years, as I highly doubt nickel anti-seize could last quite that long before it would break down.. I would check the spark plugs at least every 5-6 years just to be on the safe side
No idea guys on the installation. I did not ask. I seriously doubt I will own this car in 15 tears. I'm saving up for a new Mustang already and hope to be in one within a few years, if they still keep making V8 engines of course. Maybe I will keep my current ride if V8's go away. I'll worry about the plugs then if I'm still around at 82 years old. If I am, I hope I can still use the clutch. Knees are starting to get old already.
Supposedly the next gen S650 models will still include the Coyote 5.0 V8s, but rumor has it the upcoming S650s will also be the last Mustang to be had with a V8.. Unfortunately, it appears production of the V8 engine is gradually coming to an end
Holy crap that looks like a lot of rust on those plugs. Do you have head gasket issues? Have you done a compression test??
Zero issues. The car runs great and has from Day 1 off the dealer lot. The rust is an unknown unless caused by ethanol in the fuel, or fuel additives?? I'm guessing but my mechanic wasn't concerned. He had no trouble getting them out. Maybe it's just the age of the 15 year old originals.
The rust is an unknown unless caused by ethanol in the fuel.
Yup, it's the ethanol. It's a water attractant and it will get in the cylinders and there you go. Also, letting the car sit up and not run is not helping. 62,000 over 15 years is only 4100ish miles a year. 340 miles a month. 12 miles a day. Which I can bet it's not getting driven daily. So it rusts up. Run that car more!
This is where the anti-seize would help greatly, and why Ford says to do it in the TSB. To prevent those things from either carbon welding or rust welding and breaking off when you try to get them out.
In addition to applying high temp, nickel anti-seize, running Sta-Bil 360 every tank fill is also effective in preventing rust caused by ethanol in the fuel.
Last edited by m05fastbackGT; 2/28/22 at 02:01 PM.
Yup, it's the ethanol. It's a water attractant and it will get in the cylinders and there you go. Also, letting the car sit up and not run is not helping. 62,000 over 15 years is only 4100ish miles a year. 340 miles a month. 12 miles a day. Which I can bet it's not getting driven daily. So it rusts up. Run that car more!
This is where the anti-seize would help greatly, and why Ford says to do it in the TSB. To prevent those things from either carbon welding or rust welding and breaking off when you try to get them out.
Thanks for comin' to my tex talk.
That was a good guess on my part. Thanks for the info.
The car sits a LOT! Most of those miles are long distance highway miles driven over a 2 -3 week period each year. The last two years there have been no trips. 2020 due to Covid and this past year we took the Trans Am. Maybe 1,000 miles per year are put on locally, that's it. I guess I could use some of the Lucas ethanol treatment on occasion that I have for my T/A. No rust when those plugs came out. I do use HEET about 3 times a year to remove water from the gas tank but perhaps it is not enough. Chevron Techron once per year too, usually the first week of our travels so it won't just sit in the tank. No big deal I guess if I continue the same routine but I always consider better ideas.
In addition to applying high temp, nickel anti-seize, running Sta-Bil 360 every tank fill is also effective in preventing rust caused by ethanol in the fuel.
I would suggest this stuff to anyone not running but a few tanks of gas a year. Use the reg stabil on all the outdoor equipment yer round as well.
2/17/22, 01:36 PM
Thanks for the info. 
