Preferred anti-seize compound for spark plugs?

[RMcG]

Is there a preferred anti-seize compound for spark plugs? For example, would an aluminum based anti-seize compound be better for an aluminum block engine?

I am planning to use Denso Long Life Iridium spark plugs SK16R11 link (https://www.densoautoparts.com/find-my-part#searchResults), specs under my initial below. The present (old) plugs have been in the car for 13 years and the mileage is about 107K and they have never been changed. And I am planning to leave the new plugs in for another 100K miles. So I am thinking about using anti-seize compound.

But I am aware there is controversy about using anti-seize compound. The instructions for this plug say: "Note: The installation torque values shown above apply to new spark plugs without lubricating the threads. If threads are lubricated, the torque value should be reduced by approximate 1/3 to avoid overtightening." link (https://www.densoautoparts.com/spark-plug-installation).

See also this link (https://www.densoproducts.com/denso-plug-torque-settings) that says: "PLEASE NOTE:

Torque recommendations are for spark plugs with new gaskets.
If using anti-seize compound, use sparingly and reduce torque by 30%.
Denso has created their recommendations based on the general consensus of most engine manufactures. In the case of a discrepancy between the plug manufacturer and engine manufacturers recommendations, always default to the engine manufacturer."

If I do use anti-seize compound I will only use a small amount. Any answers to my questions at the beginning of the post or any other comments will be appreciated.

Thanks,

R.


Part Info:
Spark Plug
SK16R11 ( 3324 )
Mfr Label Iridium Long Life
Resistance 5000
Ground Electrode Tip Design Platinum Chip
Ground Configuration Standard
Ground Electrode Core Material Nickel
Center Electrode Core Material Copper
Center Electrode Tip Material Iridium
Gap Size 1.1 mm
Ground Electrode Quantity 1
Hex Size 16.0 mm
Manufacturer Heat Range 16
Seat Type Flat
Reach 19.00 mm

[bronsin]

There is no preferred compound. Use it sparingly. Just remember torque values for threads are taking dry and the compound acts as a lubricant so you over tighten the plugs if you took them to Speck! I tighten my plugs by hand for 40 years!

[bronsin]

Make that 50 years

[RMcG]

See also this link (https://www.densoproducts.com/denso-plug-torque-settings) that says: "PLEASE NOTE:

Torque recommendations are for spark plugs with new gaskets.
If using anti-seize compound, use sparingly and reduce torque by 30%.
Denso has created their recommendations based on the general consensus of most engine manufactures. In the case of a discrepancy between the plug manufacturer and engine manufacturers recommendations, always default to the engine manufacturer."

Thanks,

R.



Thanks Bronsin,

Do you think there is any downside or risk to hand tightening, i.e., not tightening enough so that there could be leakage of combustion out of the spark plug holes?

I may call the service department of one or two dealers and see if they use anti-seize when they put in these Denso plugs in themselves for a long time, like 100K miles. These Denso plugs are what is on the official Toyota Parts page at parts.toyota.com. If they do not use anti-seize then I will not use it.

It looks like I can get a torque wrench for about $20 and a spark plug socket for about $4 from Harbor Freight Tools. Rock Auto has a good price on the plugs.

Any more comments from you or others will be appreciated.

Thanks again,

R.

[bronsin]

If you have no experience installing spark plugs by the torque wrench and use it on Bear threads

Then take the plugs out at 50,000 miles and reinstall them after gapping. They’ll be less chance of them seizing that way

[bronsin]

Oh I like your comment that says use anti-seize sparingly and reduce torque by 30%. I would do it that way if I were you

[RMcG]

Hello,

I just talked to 6 Toyota dealerships and I got mixed answers from technicians who do the actual work on using anti-seize compound: 3 said definitely no, one said definitely yes, one said "I don't believe we do use it" and one said, "some of our technicians do and some do not."

R.

[bronsin]

Perfect!

[bronsin]

Well what did you decide to do?


:iono:

[RMcG]

Well what did you decide to do?


:iono:

I am actually thinking of using a form of "hand tightening" (without anti-seize compound); you have inspired me Bronsin. More details are below.

An example torque wrench that I could probably use is this one (https://www.harborfreight.com/hand-tools/sockets-ratchets/torque-wrenches/38-in-drive-click-type-torque-wrench-63880.html) from Harbor Freight Tools that has a 3/8" drive. The reviews on this wrench and other click wrenches are pretty good, but about 10% are 1 star. And if you look at those reviews (and similar reviews for other click type torque wrenches (https://en.wikipedia.org/wiki/Torque_wrench#Click), for example on Amazon) a common theme is that they are not reliable at the low end of the range and that you can't hear or feel the "click." This often leads the user to exert too much torque and strip threads or break the bolt, etc, with often disastrous consequences. I really do not need to pay a mechanic drill out a busted spark plug and clean out the resultant dust out of a cylinder.

So I think I may just get a "feel" for the proper force by practicing with my digital bathroom weight scale and knowing the lever length (e.g, 1 foot or 6 inches) I would exert the proper force with my hand. I have tried this already and it seems to work. In fact I have taken my battery operated digital scale outside by the car and I think I can practice on site and pretty accurately reproduce the proper force by feel.

The proper force would be about 13 lbs for a 1 foot handle length and about 26 lbs for a 6 inch handle length. I don't think I will use anti-seize compound, it appears to be an unnecessary complication. I want to try to stay under maximum torque to avoid any damage.

QUESTION: What do you think Bronsin?

Any comments from others will be welcomed as well.

Thanks,

R.

[mitch9521]

I never use anti-seize, I also always tighten by hand and then give about a 1/4 turn with a ratchet, never had any issues.

These cars aren't picky about torqueing down spark plugs like the Ford 2 valve Modular engines are lol

[bronsin]

I work on VW‘s in the 60s and 70s and ran into several stuck spark plug which stripped and had to be repaired. So I always use a little anti-seize. Whenever I have some.

Although I always tighten plugs by hand, I like your comment about using a little anti-seize and reducing the torque by 30% using a torque wrench.

I think you would be just fine using a harbor freight Torque wrench. I doubt they would be a problem

[tmontague]

FWIW, I always put a very small amount of anti seize on my plugs. Only enough so that the threads are thinly coated but a gobby mess like I would on other bolts.

Most plugs will come with recommendations on how to tighten then just like an oil filter does.

I believe NGK is something like a quarter turn after the plug has bottomed out by hand but don't quote me on that.

[RMcG]

Thanks for everybody's comments. I think I will educate my fingers using a digital bathroom weight scale as I said in my previous post. But, I will probably use a torque wrench as well. Harbor Freight Tools is one candidate from which to get such a tool, but there is also a loaner program that AutoZone has, see link (https://www.autozone.com/lp/loan-a-tool) . Maybe I will use a small amount of anti-seize, I am not sure.

By the way, the question of whether or not to use anti-seize compound on spark plugs was previously discussed on this forum on this thread
Anti-seize on spark plugs? (https://www.yarisworld.com/forums/showthread.php?t=59535&highlight=spark+plugs)

R.

[bronsin]

Leaving spark plugs in for the recommended 120,000 mile interval without removing them can lead to a stuck plug. Usually they will turn out if you remove the plugs with the engine heaot..

But it’s pretty scary!

[RMcG]

Leaving spark plugs in for the recommended 120,000 mile interval without removing them can lead to a stuck plug. Usually they will turn out if you remove the plugs with the engine heaot..

But it’s pretty scary!

What did you mean to say: Usually they will turn out if you remove the plugs with the engine heated? hot? What did you mean to say bronsin?

Thanks,

R.

[bronsin]

If your plugs are stuck and you’re afraid to loosen them. run the engine until it’s hot. Then try it. Works every time for me

[RMcG]

Thanks Bronsin and everybody else,

One last question. I think these Denso Iridium plugs are pregapped, correct? That means I do not and should not check the gap, because I could damage the plug correct?

In fact, I think the "11" in SK16R11 refers to the gap, correct?

See, e.g., this post Spark plug gap? (https://www.yarisworld.com/forums/showthread.php?t=55395&highlight=spark+plug+gap)

Thanks,

R.

[bronsin]

I 50+ years of installing spark plugs 95% of the time they are gapped correctly. So you still really want to check them. If you use a gaping tool you won’t damage them. I don’t believe those numbers refer to a gap

[RMcG]

I 50+ years of installing spark plugs 95% of the time they are gapped correctly. So you still really want to check them. If you use a gaping tool you won’t damage them. I don’t believe those numbers refer to a gap

Thanks Bronsin. I appreciate what you are saying, but I wonder because of what has been said in another thread on this Forum.

This Forum Thread Spark plug gap? (https://www.yarisworld.com/forums/showthread.php?t=55395&highlight=spark+plug+gap) suggests that 11 refers to gap, perhaps 1.1 mm. CT Scott in that thread also says: "Iridium plugs come pre-gapped, as you can easily scrape or crack off the coating while gapping them."

So I am wondering if I should really even check the gap. I used to clean and regap spark plugs all the time years ago. But they were not Indium plugs that lasted 100K+ miles. It seems to me that they might have lasted 20K miles and had carbon deposits on them, etc.

Any more comments will be welcomed, taken seriously and processed.

R.

[bronsin]

Very little experience with the these plugs I have. I can’t believe you would hurt them to check the gap. The iridium plugs in my wife’s 2000 Camry had 150,000 miles on them before I change them. They were so good I kept them!

CT Scott says the 11 means 1.1 mm I would agree with him. That would be about .045 inch
Whatever he says I take it as gospel

[robkay]

Last Fall (2020) I replaced the plugs in my '07 hatchback at 137k miles for the first time. I wasn't sure how tight they might be in there so I used a breaker bar. They came out relatively easily, though. I did not use any anti-seize. I didn't think it was necessary and I don't think it's a good idea on plugs. The torque spec is only 13 ft. lbs.

What a difference the plugs made, though! The car runs much better and the acceleration is much improved. I wish I hadn't waited so long.

[RMcG]

Thanks for your reply RobKay. How did your old plugs look when you took them out?


R.

[robkay]

Don't know if this answers your question, but here they are. I didn't expect them to be NGK's. I bought the car new and was expecting Denso's which is what I replaced them with. I would have used NGK had I known that was what they put in. I've used NGK in other cars. Probably doesn't matter much, though. See, the thing is, this is the first time I've ever dealt with iridium plugs, so I don't really know what looks bad. There seems to be some carbon build up on the curved part, so that certainly isn't helpful.

[bronsin]

Very heavy buildup on the threads. Wow! That’s what makes them stick! If you just clean the threads a couple of times they won’t stick and he won’t need Anti-seize

[robkay]

That buildup surprised me, too. Never saw that before. They came out relatively easily, though. Remove the plugs from time to time just to clean the threads and risk damaging the plug? I don't think too many people would do that.

[bronsin]

Remove them every 30,000 miles before The buildup on the threads happens. Clean the threads and reinstall.

There is no problem if you do that

[RMcG]

Don't know if this answers your question, but here they are. I didn't expect them to be NGK's. I bought the car new and was expecting Denso's which is what I replaced them with. I would have used NGK had I known that was what they put in. I've used NGK in other cars. Probably doesn't matter much, though. See, the thing is, this is the first time I've ever dealt with iridium plugs, so I don't really know what looks bad. There seems to be some carbon build up on the curved part, so that certainly isn't helpful.

Thanks RobKay,

R.

[bronsin]

Rob Kay That looks like oil on the threads of your spark plugs, although the electrodes look normal. How many miles on your car? I suspect you have a valve cover gasket leak that would explain the oil. You might want to check it out!

[RMcG]

Hello everybody,

I replaced my 4 spark plugs today. The NGK plugs that had been in the vehicle since I bought it new 13 years & 111K miles ago came out without a problem. I had driven the car about 4 miles though, so the engine was hot. Pictures of the old spark plugs are attached. They look pretty good, there is some carbon there, but no oil or wetness. Because the old spark plugs came out so easily, I decided not to use any anti-seize, even in small amounts.

I had obtained a "loaner" torque wrench under an auto parts store chain loaner program, but the wrench did not work. Apparently the ratchet mechanism had been stripped, so all it did was spin in when you tried to turn in the tightening direction.

So I used my "feel technique" using my battery operated bathroom scale: my ratchet wrench handle is about 6.5 " long, so I tried to feel what 26 lbs of pressure on the bathroom scale with my fingers felt like (in order to deliver about 13 ft lbs of torque). Anyway, I am glad I had this alternative method of applying torque. The car seems to be running OK.

Thanks again to everybody. A local car repair place here told me they charge $150 USD to change the spark plugs, so I figure I saved about $115 by doing it myself.

R.

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