I changed mine around 90k, right around when I did my TB and water pump job and remember them being NGKs which I thought was kinda odd. Original owner said that they'd never been changed, but iirc, they were the same NGKs that johnhav posted in the picture above.

 

Our spark plugs employ a crush or compression type washer which appears to take a set once torqued....so reuse is not best practice.

As with a lawnmower, then you know a torque wrench is highly recommended when tightening sparkplugs into an Aluminum cylinder head to avoid stripping the threads.

I use a very light coating of anti-seize compound.
Do NOT use the copper based anti-seize compound, like what Denso provides with their aftermarket O2 sensors... Copper reacts with Aluminum.

Important to used compressed air nozzle to blow any dust or grit out of sparkplug tubes before removing sparkplugs.

It is also important to clean the mating surface of the cylinder head where sparkplug gasket compresses. Spraying cleaner down into the sparkplug tube area is not recommended due to possibility of hydrolock.

I use a Wide gun barrel type whisk doused with Gumout followed by a cotton t-shirt wrapped around a long 1/4" or 3/8" drive socket extension to stop up residue.

Am interested in how others are cleaning cylinder head - sparkplug mating area...

 

I always use a torque wrench, and never use anti seize. As in not ever.

This debate exploded on the BMW forum where someone broke all 6 plugs, and blamed his wrench (which was a super expensive one from work that's regularly calibrated). Many people are able to go by feel and skip a torque wrench--there are times when a torque wrench cannot be used (like with certain shocks and struts because no access from the top--how many of us have a HVAC type that has an interchangeable head that makes it a box wrench), so ymmv....

 

Spark plug manufacturers apply a thin metal plating to the threads that acts as “anti seize” but it’s only good for the initial installation. If the plug is removed, and re installed, a VERY small amount of anti seize is a good idea since the original coating no longer exists.

To the OP- I concur with YODA, the electrode does appear worn in the photos, just replace them it’s easy.

 

I generally follow mfgs instructions, just figure to go against what they say, has to have a really good reason. We're finding these days it's happening with supplements--doctors can't understand why what they prescribed doesn't work. It's because the patient decided to self medicate with a supplement that counteracts the prescription....

"Do not use anti-seize or lubricant on NGK spark plugs. It is completely unnecessary and can be detrimental."

https://ngksparkplugs.com/en/resourc...ut-spark-plugs

https://densoautoparts.com/spark-plug-installation

 

I’m with ya John I wouldn’t touch the stuff with new plugs. Used plugs are a different story tho and therein lies the rub...
I can’t recall EVER re-installing a used spark plug.

 

Ah, gotcha!! You're saying if reinstalling.....yeah I'd be reluctant to reinstall....who knows maybe dirt is in it, etc. even with the plating, I'd be very careful taking them out, and putting new in...they may even squeak, just go slowly and let the torque wrench click if you're using one....

 

You don't want to use a TQ wrench on plugs if you are using any anti seize on it unless the heads call for it or you will increase the load on the threads 60-120% since anti seize reduces rotating resistance by around 60% and 90% of the TQ value you see is not stretch but rather rotational resistance.

That's the reason say for example in service manuals you see dry/oiled/other for every fastener since it vastly alters bolt stretch. Good example would be the cylinder heads on my truck, edelbrock says specifically to use nickel anti-seize on the plugs and set to 7ft/lb or 35 dry.

However if you have done a lot of plugs you know what the correct stretch feels like by hand even if the car in question says do it dry. It's always better to use a anti seize but as Yoda says do not use copper type. If there is any doubt simply do it dry like the manual says and feel what it is like and then replicate it with the anti seize, alum heads are dangerous since if you follow the TQ spec when lubed you will kill the threads or at minimum over work them. Same deal with aftermarket fasteners from ARP for the mains/heads/rods/ etc, you need to follow what they want not stock specs. Generally speaking the instructions on the speak plug box gets you very close or at the correct feel if you use anti seize, you would be totally amazed how little TQ you need to prevent them from ejecting actually.

You need to use a very very low vapor pressure cleaner like brake clean or carb cleaner if you are going to spray down the tubes to ensure it evaporates quickly and allow at least 20 min after spraying before installing a new plug and make VERY certain you used a air gun to remove any metal particles from the tube before removing the old plug. You can cause a lot of damage if you don't make sure there is no rust flakes that can fall in the cylinder. The plug tube design the 430 uses is one of the most dangerous in terms of stuff getting where it's hard to remove vs say an LS engine

The plugs in question look fine as it sits but are worn as Yoda pointed out so it would not hurt to replace them, burn looks good and I don't see anything that would alarm me. Also as he said the crush washers are not reuse-able so don't do any testing with the new ones, use the old ones to get a feel

 

Eh, I've installed over 2500 no issues. Problem is people don't understand how much anti seize reduces resistance in a TQ wench and massive increases stretch at the same reading. You just need to know what it feels like and it helps hugely in guarding the threads and easing the next go around, on any high performance engine it also allows easy plug checks at the track.

 

If anti-seize equates to lubricant then Denso suggests reducing torque value by 1/3:

 

LOL on the BMW forum the guy said listen I build race engines blah blah blah, yet he broke 6 plugs. To each his own. That dude used this +/- 2% 1-20 Snap On torque wrench that cost over $500 and is calibrated regularly, he still broke 6 plugs. I mean dag his wrench is good down to 4 ft. lbs., bet you few if nobody here has anything like that. I've got a 5-75 that can go down to 15 +/- 4%

Again, just me, how scientific is it, to arbitrarily back it out by 5.1 ft. lbs because you put anti seize? Let science do the work.

 

Yeah I have those snap on wrenches too, I never use them for plugs for a reason. I have had too many customers come to me for head repair since they used TQ wenches and killed threads. You can't use it for plugs unless the head is NEW and threads chased with a tap, any other situation it will be wrong if you go off a set value. You would have to clean the threads and crush washer seat or do it by feel, I do the latter since I don't want to have to explain to customers why the job took me longer

Be my guest and use a wrench on anything less than perfect threads and see what the result is. The packaging on the replacement plugs says snug and 3/4 turn for a reason NOT a spec.

 

Sorry, had to make an unexpected trip and couldn't get back to this. THANK YOU all so much for the great information and insights.

I reinstalled the plug I removed for inspection and the car is still running fine as ever. But based on the conversation here, I'll change the full set at my first opportunity. I reinstalled (bare) by feel, and certainly didn't gorilla it. I'm sure I'll make the full replacement within 1500 miles (busy days this month) and trust I'll be able to remove it again. I do have a basic torque wrench, nothing fancy. I feel okay about doing it by hand but just in case I use the torque wrench, does anyone happen to know the spec for the '06 LS 430?

Again, thank ALL of you for the helpful input!

 

The point on the BMW forum was folks said the mfg of the plugs states not to use anti-seize, and common sense says if you do, 17 ft. lbs on an accurate wrench, which you have, is too much torque. Why would anyone disregard the mfg's recommendation? There are times it makes sense to, there are times it doesn't make sense to. Like on my wife's top torque strut job--GM has the tech disassembling the electrical box adding maybe more than .5 hours to the job. Why do that if you don't have to? So maybe it makes sense to not follow the mfg's recommendation (I saw a YouTube where the shop didn't explain it but I said whoa, they were able to move it out of the way and hold it with a tow strap).

Guy on the thread was actually a reasonable guy, more often than not we're used to on those heated threads, having the person who's wrong burn the thread down and leave. In this case, the guy was sincere about wanting to know why he broke all 6 plugs when his wrench was set to 17. My thing is you use anti seize, how are you ever going to get it out of the threads? The next set of plugs also likely cannot be torqued to spec any longer. Again, there are many scenarios where one cannot use a torque wrench, it either can't access the job or a very common scenario with with a strut, there's no access from the top. That's why in HVAC they make torque wrenches that have box wrench heads. For a DIY person, it's not worth it to buy them so yes go by feel. Anybody who goes by feel on my wheel lugs or nuts? I'd redo them myself, not into the I eyeballed it with my impact wrench thing

edit ps the box on the spark plugs don't have a torque spec because they go into multiple engines/heads, every engine absolutely has a spec

 

Not really, you only need to seal the plug to be head. I'm sure if that was not true I would have have issues with engines I've worked on but never have, also explain why high end head makers all say to use it and just snug and crush the washer if it is impossible to get right?

You do NOT need to have the plug to a spec for it work, you need it to seal and not back off and not stretch out the threads (the real issue here) in the head when doing so. Again you would be astounded how little force you need to prevent plugs from leaking or backing out, my friend did his own plugs and was terrified of killing thread and had them HAND tight for 85k miles.

The guy on the forum broke his plugs because the 17 spec is not accurate, the effect of any lube depends on the lube used, the thread type, the rotating surfaces (head/seat area) and uniformity, and most critically material density. If you apply ARP lube to rolled threads that are in spec how much is the reduction to rotating TQ and thus the resultant increase in fastener stretch? Even if you would calculate for the same theoretical tension and then try to apply that "correct" TQ value to a stock fastener you would distort the actual fastener and then destroy threads.

Riddle me this. My performance engine specs 50 for step one and 105 for step two for the heads, however ARP want you to do three 33.333 steps up to 100 using their lube on everything threaded and the underside of the bolt heads. The studs want 110 with the same instructions. What is the actual clamping load differences and bolt stretch between the three?

We are using the same head/block for all of this. Same deal with plugs, you CANT use a a spec that assumes NEW threads in the head that have never seen any TQ (aluminum is very much weak to repeated TQ events and is why any alum fastener is single use) and the thread geometry is perfect as is the sealing seat for the plug with no debris and uniformity issues. For the first plugs and only for them can you use manufacture spec and it will likely "overkill" what is needed to seal/seat properly, for everything after that you would need to reset everything back to factory to be able to use that same spec. You can't just say "anti seize reduces the TQ value X% since it ranges massively since the TQ value you see on any tool is the rotational TQ NOT the actual clamping load and more importantly fastener stretch. You can easily apply even engine oil to a M5 fastener that would otherwise normally trigger the tool at its usual 30-50 inch pounds and set the tool to 15 and pull the bolt apart. If you measured it via stretch dial (what I use for engines what don't use TTY bolts) you can ALWAYS see if the fastener has reached peak clamping regardless of what the TQ wrench says since it's blind to the two most important metrics.

The thing about plugs is that rotational force can't easily be measured since it uses that crush washer that can allow a "correct" setting that is "correctly" adjusted for dirt/lube whatever distort the threads. Only 10% of given force you put into a rotating bolt translates to the bolt stretch, if you add lube that reduces rotating friction by 30% but then reduce the ROTATIONAL spec by 30% then congrats. You more than doubled fastener stretch and likely are distorting the threads and parts.

Do plugs like the NGK box says with or without lube and it will feel the same to your hand, just try it. Then do it by feel and mark how much you turned it vs the box, it will line up. Lastly take a snap on digital inch/lb wrench and check the rotational TQ spread between all plugs and it will be WAY lower than spec but within 10% of each other. For the ultimate in seeing my point take the head off and stretch gauge the plugs, you will see that if you follow the new head only spec you are over stretching the plug and head threads