Spark Plugs Replacement question?

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Originally Posted By: KrisZ
I use antisieze on all plugs, coated or uncoated since my vehicles have aluminum heads. I use very little dough and go by angle of rotation, rather than torque when installing plugs.


Me too, I use a small dab on just one side of the threads and while tightening it works itself everywhere. I just snug them well(more like a judgement thing) and don't tighten the [censored] out of them!
 
Originally Posted By: zzyzzx
Even if you can use plugs for a long time, it's still good to remove them and check the gap.

Easy on some cars and a huge PITA on others. The real irony is that one of the reasons for long-life plugs is because it's a pain to access. And if they're not periodically checked and reinstalled, they get harder to remove.

I remember the original ND platinum plugs on my '95 Integra GS-R. While I did replace them, I regapped then against the instructions of the manufacturer because I couldn't find anything (outside dealer parts) with a 1.3 mm gap. They used to have an ad saying that Denso platinums could conceivably last the life of an engine. Even after 70k miles (more than the recommended 60k replacement interval) the gap was perfect and the platinum material intact. I actually put back the factory plugs and checked them periodically for wear. My wife's Civic actually came with NGK Laser Platinums from the factory. I just felt like doing something and replaced them. The plugs were still fine after about 65k miles and 12 years. I guess it's a bit odd that a car this easy to change plugs comes with platinum from the factory, but a lot of manufacturers use long maintenance intervals as a selling point.

Long-life plugs don't work like standard plugs. All plugs obviously get corroded from being exposed to the combustion chamber. Standard plugs supposedly fire better when they're newer with sharper edges. That's why NGK and Denso have standard plugs with extra edges like V-Power and U-Groove. They're not really gimmicky like Splitfire. The platinum and iridium plugs use a smaller platinum or iridium tip that's supposed to get hot enough to self clean. NGK and Denso are know for bigger, more durable tips.

I guess only Bosch goes to the extreme of a thin platinum wire that's buried flush with the insulator. I used to take my car to a shop (Japanese car specialist) that only stocked Denso plugs and used them in everything, including makes that didn't spec them. They could order NGKs if the customer insisted. I remember talking to the owner about when they used to use Bosch plugs. I guess their standard plugs were OK, but they kept on getting the platinum plugs back with no center electrode left.
 
Originally Posted By: maverickfhs
Can Iridium and platinum plugs be gapped? I thought it's only true for Copper ones, isn't?


Originally Posted By: Denso
In most cases your Iridium Power plugs do not need to be gapped. Even with small variations in the factory set gap the ultra-efficient firing power design will compensate for those small variations. Should you decide to re-gap your Iridium Power plug, use extreme caution as improper gapping may damage or destroy the Iridium center electrode or porcelain center.
 
Originally Posted By: maverickfhs
I appreciate your input and help 'y_p_w'. At least from now on, I'll use the term 'standard plug'
smile.gif



Oh - I got corrected once. Since then it's been a pet peeve of mine even though I know it's in common use.
 
One more question, does these plugs need to be replaced based on mileage or number of years?

On my CLK, they got replaced at 64k miles with Bosch 0242230500 in 2012 and currently I have ~82k. Should I be concerned or no?
 
Originally Posted By: ARCOgraphite
You can glaze the insulator with bad mixture or additives then youll get high misfire count regardless of how sharp the electrodes are or how close to spec the gap is. Unfortunately With MPFI its hard to separate cylinder (power) balance issues relating to fueling or spark or gunked valve heads.

If you take a plug out of a 4V Aluminum head, you should ALWAYS use a new plug gasket to prevent distortion of valve seats due to overtorquing. Properly designed Plugs have zinc or ?? coating in the shell metallurgy to prevent seizing. IDK if Motorcrapft/ Autolite learned anything the past decade about anti-seize plating.

Never had a problem provided I used a torque wrench. I don't even know how to remove the old gasket without something like a wire cutter.

The strange thing about the last time I installed some plugs was that I couldn't get the gasket to crush.
 
Originally Posted By: y_p_w
Originally Posted By: ARCOgraphite
You can glaze the insulator with bad mixture or additives then youll get high misfire count regardless of how sharp the electrodes are or how close to spec the gap is. Unfortunately With MPFI its hard to separate cylinder (power) balance issues relating to fueling or spark or gunked valve heads.

If you take a plug out of a 4V Aluminum head, you should ALWAYS use a new plug gasket to prevent distortion of valve seats due to overtorquing. Properly designed Plugs have zinc or ?? coating in the shell metallurgy to prevent seizing. IDK if Motorcrapft/ Autolite learned anything the past decade about anti-seize plating.

Never had a problem provided I used a torque wrench. I don't even know how to remove the old gasket without something like a wire cutter.

The strange thing about the last time I installed some plugs was that I couldn't get the gasket to crush.


I cannot understand how someone can over tighten a plug. The threads are quite long and I would think it would take some serious torque to damage. Does everyone not realize it doesn't take that much to hold a plug in place?
 
Originally Posted By: philipp10
Originally Posted By: y_p_w
Originally Posted By: ARCOgraphite
You can glaze the insulator with bad mixture or additives then youll get high misfire count regardless of how sharp the electrodes are or how close to spec the gap is. Unfortunately With MPFI its hard to separate cylinder (power) balance issues relating to fueling or spark or gunked valve heads.

If you take a plug out of a 4V Aluminum head, you should ALWAYS use a new plug gasket to prevent distortion of valve seats due to overtorquing. Properly designed Plugs have zinc or ?? coating in the shell metallurgy to prevent seizing. IDK if Motorcrapft/ Autolite learned anything the past decade about anti-seize plating.

Never had a problem provided I used a torque wrench. I don't even know how to remove the old gasket without something like a wire cutter.

The strange thing about the last time I installed some plugs was that I couldn't get the gasket to crush.


I cannot understand how someone can over tighten a plug. The threads are quite long and I would think it would take some serious torque to damage. Does everyone not realize it doesn't take that much to hold a plug in place?


The average person could easily damage the threads. And there's the consequence of under tightening.
 
Originally Posted By: maverickfhs
2- Is it a good practice, to occasionally remove these plugs and put anti-seize on them so they don't seize up?


Don't use anti-seize on any silver spark plug threads; only on black phosphate coated threads. Use a light oil on silver threads. Pull them every 30K for a re-gap.
 
Originally Posted By: philipp10
Originally Posted By: y_p_w
Originally Posted By: ARCOgraphite
You can glaze the insulator with bad mixture or additives then youll get high misfire count regardless of how sharp the electrodes are or how close to spec the gap is. Unfortunately With MPFI its hard to separate cylinder (power) balance issues relating to fueling or spark or gunked valve heads.

If you take a plug out of a 4V Aluminum head, you should ALWAYS use a new plug gasket to prevent distortion of valve seats due to overtorquing. Properly designed Plugs have zinc or ?? coating in the shell metallurgy to prevent seizing. IDK if Motorcrapft/ Autolite learned anything the past decade about anti-seize plating.

Never had a problem provided I used a torque wrench. I don't even know how to remove the old gasket without something like a wire cutter.

The strange thing about the last time I installed some plugs was that I couldn't get the gasket to crush.


I cannot understand how someone can over tighten a plug. The threads are quite long and I would think it would take some serious torque to damage. Does everyone not realize it doesn't take that much to hold a plug in place?


The amateur will almost always over tighten...after all, dont want them spark plugs to come flying out through the hood.
 
My Cavalier still had the factory installed AC Delco Iridium spark plugs when I got it at 180k miles.
It had no misfire and ran well. I changed them immediately, they are easy to do on an Ecotec.
They were definitely worn out, one the center electrodes was mostly gone, really surprised it did not misfire on that cylinder.
Replaced with new Delco Iridiums and planning to run them 100k if the car lasts that long.

I would have no trouble running a newer car with Iridium plugs 100k on a set of plugs, but I wouldn't push it much past that.
 
Originally Posted By: philipp10



I cannot understand how someone can over tighten a plug. The threads are quite long and I would think it would take some serious torque to damage. Does everyone not realize it doesn't take that much to hold a plug in place?

Dealer techs use impact guns to install plugs all the time.
 
Depends on the vehicle.

My mom's Saturn Vue with 120,000 miles (2.4 ecotec) had plug that looked almost new when I replaced them (iridium fine tip).

My Brother in Law's '04 F150 (3v 5.4) had plugs that looked horrible (single platinum).
full-4879-1433-plug_2.png


I also follow black threads-antiseize, silver threads- no antiseize rule. I also use a torque wrench when I install them.
 
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