trailor

anti-seize, while not discouraged, is not recommended by Ford. there is no need for it if you torque them down to spec....

cliffyk

If I did not have a proper torque wrench (a situation I cannot envision), and given the many years I have been doing this sort of work, like JC316 I too would likely torque them based upon "feel". However I would not recommend, or support such a recommendation, being made to anyone else.

It would be quite unwise to not torque the plugs on these engines for at least a couple of reasons; the use of tapered seat plugs in plug bores with minimal threading, and that it is almost commonplace for our engines to spit out plugs that were like not torqued properly or installed in bores damaged by over-torquing in the past.

Ford's engineers decided to recess the plug bores and leave only 5-6 threads remaining at the bottom of the bore. I am certain this was done because of the extended service life of the platinum plugs chosen for OEM fitting--100k miles. Anti-seize would not survive that long, and a 3/4" reach plug in a fully threaded bore would certainly seize up over that period, 6 to 8 years or more of "normal" driving in the US.

Under normal service intervals the plugs in our cars would only be changed once (at 100k), maybe twice (at 200k) over the entire life of the vehicle. It's only we "enthusiasts" that change them about as often as our underwear--I changed mine 3 to 4 times a day, over a period of a week and a half, last summer when doing field tests for a COP and plug vendor.

Get a 1/4" drive torque wrench, an 8" extension, a 1/4" to 3/8" adapter, and a decent plug socket (Google "extended spark plug socket").

Since last fall I have been using a torque limiting plug socket:



read more about that here...

kingrukus

Since I plan to change plugs more frequently than 100k miles, should I use anti-sieze? will anti-sieze create an error in the torque reading?

stevednmc

+1! That is the exact torque wrench I bought for the job. Used some Antiseize, set the torque at 12lbs, and havent had an issue yet. I did my plugs at the same time I changed my injectors. Easy job, as long as you dont try and short cut and use you brain.

kingrukus

Any tips for removing plugs that have never been changed before? Car is 12 years old, but only has 48k miles on it. Perhaps I shouldnt even bother changing them since they are supposed to last 100k miles? The age worries me however.

cliffyk

It will, however not enough to make any difference at such a low torque. The plug has a M14 thread which if used as a fastener would be torqued to 40 to 45 lb-ft. At 11 to 15 lb-ft the effect of the lubricant is negligible.


I would not change them until 85k or more, unlike the fluids spark plugs are one of the things on an engine where age is not a significant concern.

What you should change are the fluids, rear-end, tranny, brake and p/s fluid, and coolant...

kingrukus

Thanks. Your website (paladinmicro.com) is also very helpful!

JC316

Done quite a few of these 4.6L motors and I have lost count of how many other engines I have done without a torque wrench and I have yet to have a plug spit out on me. Stuff like head bolts and intake bolts. the torque wrench comes out, but I just never think about it on spark plugs.

cliffyk

You are obviously an experienced mechanic, quite different thing from telling someone on a forum that they do not need to use a torque wrench--"crank em down till they are tight." I install them all snugly, then it takes less than a minute to torque all 8.

Not using a torque wrench on spark plugs would get a mechanic at a FAA certified repair station fired...

stevednmc

I guess thats the difference between spark plugs at ground level and spark plugs at 13,000 feet eh?