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Here's a Tech Bulletin from NGK on the subject. They state that all NGK plugs have a metal plating on the threads that acts as an anti-seize and nothing else is necessary, and in fact can cause problems. Some recent threads on this BB have shown a diversity of opinions and techniques regarding the use of anti seize.
NGK says only plugs with no coating would benefit...here's their bulletin:
http://www.ngksparkplugs.com/pdf/TB-0630111antisieze.pdf
--
Bob: son's XC70, dtr's '94-940, my 81GL, 83-DL, 89-745(V8) and 98-S90. Also 77-MGB and some old motorcycles.
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That's because a LOT of people never pull their spark plugs. Honda says the plugs get replaced at 100K miles, and the anti-seize probably won't last that long anyway.
I have NEVER used a torque wrench on spark plugs. With or without anti-seize, they get finger tightened until it stops and then snugged about 1/4 turn, if that much.
Klaus
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My name is Klaus and I am a V ♂ lv ♂ holic
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I tend to sway towards the Klaus method:
"I have NEVER used a torque wrench on spark plugs. With or without anti-seize, they get finger tightened until it stops and then snugged about 1/4 turn, if that much."
However,in my situation, I use a dab of anti-seize every time I change plugs due to the fact that previous owners of my Volvos have over-torqued the plugs, and there are some issues with smudged and/or compromised threads.
Bottom line: the aluminum is soft compared to the steel of the plugs. How many times have you heard of an 'under-tightened' plug? Has anyone ever had a plug fall out, or become un-screwed because it was not torqued down enough?...Like Klaus says:"..With or without anti-seize, they get finger tightened until it stops and then snugged about 1/4 turn, if that much."
Right on KlausC!
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The problem with your method (Klaus's method, my method) is it relies on vague measurements, like "finger tight." It works for you, Klaus, and me, because we presumably have experience.
The manufacturer cannot presume all of its DIY customers have that experience or define torque by average finger strength in everything from a nearly new warm head to cold ones with half a million miles of poor maintenance.
Their problem is the spark plug is usually item 2, up from an oil drain plug, to which the brand new home mechanic will apply a wrench. My guess is a much higher percentage of "new DIYers" are learning from a book or an internet forum, without the benefit of a good teacher or an occasional pat on the back or snick on the head.
--
Art Benstein near Baltimore
Draw your curves first and then plot your data!
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There are two places on the engine where I use the finger-tight value when torquing something (and I should clarify that this is on a "shorty", 6-inch, ratchet handle because the handle length is a major factor!):
1) on the spark plugs, using my whole hand on the 6-inch handle, but not vigorously;
2) on the nuts holding down the thermostat housing cover, and here my "finger tight" is actually using just two fingers, a thumb-and-forefinger, on the shorty handle.
And I use my favorite antiseize, a ceramic-based (non-metal impregnated) white paste, good to 2,500 deg F/1,400 deg C., on these and almost every fastener I encounter on the car (except those calling for loctite such as the caliper bolts), including the lug nuts (but I use only 3/4 the specified torque because, I believe, this value was supposed to be clean and dry threads).
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As usual, good point(s) Art.
"fingertight", is not for neophytes?
I have a good friend who is fastidious and obsessive about using absolute proper and perfect torque on every bolt and/or nut.....I admire and pity him(?)
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"'fingertight', is not for neophytes?"
Well, it is confusing to me as Klaus wrote it. Fingers on what? For example, I get the first thread or two started with finger and thumb twirling the plug's terminal. Not much room for more than that. Just turned in enough to make certain I'm not cross-threading.
Then I use the plug socket alone, using finger and thumb on the hex top it has. Sometimes I can get the plug all the way to the gasket that way, often not.
Then the next tool is the ratchet - a 3/8 drive. The feel of the gasket beginning to compress is the next goal. A bit of that, and done, and no, I don't recall what angular movement follows the first gasket contact - it is just muscle memory at that point.
I do leave plugs in way too long, and the copper anti-seize grease I put on their threads may or may not have helped them to come out again. Some have had to be worried out -- a technical term for working them back and forth gently while pouring on the penetrating oil while mulling over all the plug thread rescue techniques I've read about over the years. Using a greasy thread chaser precedes the replacement plug installation. So far I've been fortunate not to need repair to a plug hole.
And yes, I have read several times on this forum of others whose plugs "shot" out while driving (all threads intact) and the other plugs were partially backed out as well. Not firsthand experience, just surprising reports. So to me, it can only be explained by a large variation in our perception of "tight enough."
--
Art Benstein near Baltimore
"It could be said that burning wood for home heating is choosing 'a way of life,' rather than just choosing a fuel." - John Siegenthaler
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"Well, it is confusing to me as Klaus wrote it. Fingers on what? For example, I get the first thread or two started with finger and thumb twirling the plug's terminal. Not much room for more than that. Just turned in enough to make certain I'm not cross-threading.
Then I use the plug socket alone, using finger and thumb on the hex top it has. Sometimes I can get the plug all the way to the gasket that way, often not.
Then the next tool is the ratchet - a 3/8 drive. The feel of the gasket beginning to compress is the next goal. A bit of that, and done, and no, I don't recall what angular movement follows the first gasket contact - it is just muscle memory at that point. "
Art;
That's the exact same procedure I use.I hope you got one of those3/8 ratchets with a stubby handle.I sort of think of it as a poor mans torque wrench)?(
As for the plug shooting out while driving; yes, it happenned to me when I first got my first 240....for a couple of weeks,I assumed I had an exhaust manifold leak.I ordered new manifold gaskets,and then,one day I'm driving along and; BAM...I pull over and find the #4 plug has shot out of its hole,and it was danglin' by the plug wire, and the plug threads were filagreed with smudged engine block metal!..so,I bought one of those sleeve installation kits.It was sorta pricey,(about$55 bucks),and I was expecting the worst, but it worked very well.
Like you suggested; "tight enough" is in the mind of the beholder.
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Yeah, admire, but pity. I once met a mechanic, one with a big tool box in a real garage, who.... now this is a really true actual fact, that I witnessed...
did not use sockets. He felt that the only correct way was to use a box end wrench, and would go to great lengths, such as buying Snap-On wrenches in different lengths (they used to make 3 lengths) so he wouldn't have to use an open end either.
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Yup..
..by gum.
..come to think of it,
,,admiration and pity can apply to alot of people,,
...including myself)?(
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I began using anti-seize on spark plugs over 40-years ago, when I began doing a lot of VW and Corvair engines. I continued to use it and have on a wide variety of engines. Has it always been necessary? Don’t know, but have never had a problem and will continue to use it.
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posted by
someone claiming to be ibs740
on
Thu Apr 12 06:56 CST 2012 [ RELATED]
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The problem here is that these bulletins are prompted by the Home Depot effect...yes we can... but you really shouldn't because they haven't a feel for too much.
People lubricate a thread which lessens the friction increasing the torque as was mentioned earlier. What the bulletin doesn't address is just how much torque it takes to stretch/crack/snap off a plug. Yes these were the skinny plugs (10mm), all my bricks are 14mm.
I have always used anti-seize on my plugs and plan to continue to do so.
The manufacturers like you to replace their plugs every time you pop them out, it's just good business. Maybe a good question for them would be does their special coating last for multiple insert and removals?
ian
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The NGK bulletin I posted makes it clear that the plating is sacrificial - it is removed from the plug threads when you unscrew the plug the first time. If you reinstall the old plug, anti-seize may be useful.
At $2.00 each, and a 20k-30k mile life, I don't reinstall old plugs.
--
Bob: son's XC70, dtr's '94-940, my 81GL, 83-DL, 89-745(V8) and 98-S90. Also 77-MGB and some old motorcycles.
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NGK's concern is about over torquing the plugs due to anti-sieze lubrication of the threads. It`s a valid concern. Most reference manuals suggest reducing torque by 33 to 50% of DRY thread torque settings on most all applications.
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Informative link. Thanks for posting. I was on the NGK site yesterday, but didn't see that one.
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Will watch with interest. Just put my NGKs back in with anti-seize.
--
"Do you think that's air you're breathing now'? (The Matrix 1999) '89 764 (retired), '94 940T (319K), 92 245 (207K)
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And i have done the same thing for years but then spark plug #2 was getting really hard to get out and I cleaned all the anti seize off the threads of the plug..I ran a tap carefully into the plug threads....The tap came out with a lot of anti seize on it..The tap didn't need much help so the threads were probably so loaded with the stuff that i think i had the problem they mention...My recommendation is if your going to use anti seize..Use just a bit then wipe off any excess...The coating on the plugs they talk about is probably high in Zinc..And that is a nice metal that helps stop galling..Normally zinc is used as a coating so things don't rust..If you see that gold,silvery,green tint on plugs then that is what Zinc coating looks like...Nuts and bolts are also coated with it when they look the same...Just saying and just sharing!!
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I don't have any trouble believing that coating or plating technology has advanced over the years. I used anti-seize for years on water and air cooled engines without any problems.
I once heard a rumor that it interfered with heat transfer. However, since anti-seize compound is usually made with powered aluminim or copper I found that hard to believe.
I would always follow the manufactures recommendations. Besides, they're the ones with all the engineers.
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Me too. I use Permatex brand anti-sieze on the copper NGKs and Bosch in mine since like 1994 BCE.
I use a sparing amount. When I go to regap the clearance every 5000 miles or so or just before emissions (like today), I usually don't have to add more. I do reduce the torque a bit as the thread is now lubed by the anti-seize compound. It seems to "stick around" with one application.
Welp, Happy Holidays everybody!
cheers,
MacDuff.
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