Re: Want to replace spark plugs on '05 GT.... should I really be scared?

by BMMC1 on November 5th 2009, 7:25 pm

03.sonicblue wrote:
Leonard 95 wrote:I really don't think there that much of a problem on mustangs, 5.4 3 valve trucks, your gonna probably break around 50% of them if it has 100k on it. Even with warming up and doing a induction flush on the trucks, they still break alot.
I have a 3v 5.4

You're screwed now! Game over man!

by 1 fast 8 on November 5th 2009, 11:18 pm

paul i think you may be pleasantly surprised mine was missing at the top of 4th and 5th they didnt look bad but i went away with new plugs

by BMMC1 on November 5th 2009, 11:29 pm

Good to know. I hope you're right! It would be nice to solve the problem.

by 03.sonicblue on November 6th 2009, 8:37 am

Have you driven it yet?? Whats the status?

by 07Shelby500 on November 6th 2009, 8:59 am

It's broke.

by LightningTech on November 7th 2009, 10:28 pm

The problem is excessive carbon build up around the electrod's porcelain tube. If you do routine induction and fuel injector flushes that should break up and remove the carbon so there won't be a problem removing the plugs. On vehicle with exccessive mileage we usually flush the induction and fuel systems two times and then remove the plugs on a warm engine. Motorcraft carb cleaner is the best to use to remove the carbon after you break the seat on the plugs and let set with the carb cleaner. Usually only 1 or 2 plugs will be a problem, but that is when the remover comes in handy.

by blkpwr on February 7th 2012, 3:53 pm

Metric7 wrote:I've replaced mine with a one-piece plug, but my engine had only 12K miles on it at the time. I recommend replacing yours ASAP; these are poorly-designed plugs in these engines and no way I'd let the factory two-piece plugs sit in there for 100K. I had no problem removing mine, but they make a horrible grinding sound as you remove them - that was unnerving. Put nickel anti-seize on the threads of the new plugs before installing them. There's a TSB on removing/replacing these plugs somewhere out there on the internet; I'll look for it when I get the chance - it's a pretty good guide for R&R.

**Edit** - here's a thread with a bunch of useful info, including the TSB: http://www.fnsweet.com/forums/05-09-roush-mustangs/44003-ford-spark-plug-tsb.html

I've read this, the other thread on plugs breaking on this site as well as several other sites, and have only heard of the champion 7879 one body spark plug replacing the two part spark plug. What did you use to replace yours? (or anyone else reading this)

I read here http://www.fordtough.ca/forums/showthread.php?t=5439 that champion plugs are bad on fords, as well motorcraft came up with its own plug it considers one piece and solving the breaking problem.
update- I just called the dealership. the linked page concerns 5.4 f150s which wre 3V apparently, my 4.6 is not.
however, the dealer just told me that ford had a one piece for my mustang (06 gt) part sp514. 26$ a plug

by 07Shelby500 on February 7th 2012, 4:42 pm

Your 4.6 IS a 3V

by blkpwr on February 8th 2012, 12:03 am

I meant my f150 isnt a 3v sorry for confusion

Also I learned that motorcraft has spark plugs now that are single piece

by MrClark on April 20th 2012, 12:25 am

Whats the ramifications (if any) of installing the brisk racing silver 3VR14S plugs on a lightly modded car..... Everything I've read says 450hp and up.... I have a set of 8 on hand... I haven't seen what's on the car right now yet... But it's got 72k miles and I'm sure it won't be pretty....

by BMMC1 on April 20th 2012, 8:30 am

I'd stick with stock. Will they run? Yes. But you might notice a slight hesitation when the motor is cold and you risk build up.

by 07Shelby500 on April 20th 2012, 9:45 am

Those are one heat range colder than stock. Really for a FI setup to keep the detonation chances down. Not sure what they will do in NA cars. Performance may suffer.

by Psycho Bob on April 20th 2012, 9:56 am

alot of the guys that were using the brisk plugs on S197forum said they don't last as long as the autolite plugs.

by MrClark on April 20th 2012, 10:19 am

i see... I was just curious and there is a new set of them in a box of misc goodies i got... so the Autolite HT0 will work? im curious how hard these will be to get out assuming the previous owner didnt change them...

by Psycho Bob on April 20th 2012, 12:49 pm

pretty sure these are 100k plugs (according to ford). my wife changed the plugs in her 3V expedition at 125k and they weren't horrible.

really though you probably could use HT0's, but without forced induction you want to use the HT1's

by 07Shelby500 on April 20th 2012, 1:33 pm

I broke 4 of 8 on the wifes car just last month while changing them. Followed the TSB to the letter. Wasn't fun getting the broken part out.

by BMMC1 on April 20th 2012, 1:52 pm

I had luck with:

1) warming the car up
2) spray wd-40 down into the the plug ports
3) let soak overnight
4) warm the car up
5) one by one, remove plugs.

I didn't break one. HOWEVER, mine only had like 18k miles on it.

by 07Shelby500 on April 20th 2012, 2:26 pm

Ya. Hers were just shy of 100K. I used PB Blaster penetrating oil. Let soak forever. Really frustrating.

by MrClark on April 20th 2012, 3:52 pm

the HT1's are $95 at Oreilly's and Autozone..... so i need to warm up the car later tonight... spray a penatrant into the plug holes and let it sit overnight... warm up the car tomorrow and turn each one an 1/8 or so... spray more and let sit for another hour or so and then work on each one slowly.............. then... put on the CAI... the pulleys... tune the SOB and hit the street!

by 07Shelby500 on April 20th 2012, 6:28 pm

George Shouse can get the plugs cheaper. Give him a ring at standard supply Owasso.

by Psycho Bob on April 20th 2012, 11:42 pm

i just bought the plug removal tool. she did soak them a good bit, but really the tool was so easy to use she didn't even bother trying to ease them out.

by Shelby10' on April 22nd 2012, 2:30 pm

The plugs I just baught for my GT500 were only $15.00 hehe

by blkpwr on April 23rd 2012, 12:43 am

I changed plugs his weekend to motocraft sp514

The number one plug broke the rest were fine. I got a lisle extractor tool. For it at Oreillys. Autozone doesn't carry them. Don't be timid south the lisle tool. Crank it until you can't crank further. It worked fine. I'm on tulsa now heading back to the panhandle tues with tool so if anyone needs to change plugs and needs the tool