NGK do not recommend the use of "anti-seize" on the threads as they are nickel plated for that purpose.
Macka
Macka
Spark Plug life
- Thread starter DirtFlier
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Warren
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Putting anti seize on the threads also messes up the torque setting assuming you are using a torque wrench.
I am finding that in applications where spark plug change intervals are around 60,000+ miles, they are extremely difficult to remove unless a never seize type product is used when installing them.
I have found this with different brands of spark plugs including NGK which I typically use.
I recently changed the plugs in my 2006 Subaru Forester 2.5 Turbo which has NGK plugs and a spark plug change interval of 60,000 miles. It took me around 5 to 10 minutes to unscrew each plug from the head which was partly due to the very poor access but equally due to how tight the plugs were when removing them and the length of the thread on the spark plugs.
Seagrass
I have found this with different brands of spark plugs including NGK which I typically use.
I recently changed the plugs in my 2006 Subaru Forester 2.5 Turbo which has NGK plugs and a spark plug change interval of 60,000 miles. It took me around 5 to 10 minutes to unscrew each plug from the head which was partly due to the very poor access but equally due to how tight the plugs were when removing them and the length of the thread on the spark plugs.
Seagrass
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ST1100Y
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Yes, but heat-cycles and vibration can still lead to a crack in the ceramic insulator -> shunt -> no spark...
(BTDT on a 4 cyl with 2 coils and "wasted spark system"...)
So I'll stick to the 12,000km interval...
OP
OP
DirtFlier
Site Supporter
I've found that I can double the change interval recommended in the Honda owner's manual using the standard NGK spark plugs without any noticeable degradation in performance or fuel economy. And I always dab some anti-seize on the threads when installing new plugs to prevent them sticking in place!
karl
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getting old is not for weak.
A lot of the difficulty removing old plugs comes from the carbon buildup on the threads inside the combustion chamber, this carbon gets peeled off when the plugs are removed.
Coyote Chris
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BTW
BTW, before i bought my 2018 Forester I test drove the turbo version. I wasnt that impressed, and the cost of the extended warrenty was significantly more with the turbo.
OP
OP
DirtFlier
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"...It took me around 5 to 10 minutes to unscrew each plug from the head which was partly due to the very poor access but equally due to how tight the plugs were when removing them and the length of the thread on the spark plugs...seagrass"
Years ago I helped my son replace the spark plugs on his 2005 Civic coupe. Three of the plugs came out taking only normal effort but the fourth one was a real struggle and fought us every turn of the ratchet. I was afraid I was removing alum from the threads in the cyl head but luckily it was only carbon causing all that drag.
Years ago I helped my son replace the spark plugs on his 2005 Civic coupe. Three of the plugs came out taking only normal effort but the fourth one was a real struggle and fought us every turn of the ratchet. I was afraid I was removing alum from the threads in the cyl head but luckily it was only carbon causing all that drag.
This difficulty with removing the plugs is the reason that I never use "long life" plugs like Iridium as a replacement for standard (copper) plugs.
I only use Iridium or Platinum if specified by the manufacturer.
The standard copper plugs in my 700 were changed for the first time at 48,ooo km. They looked great and had never miss-fired.
Fuel consumption did not change after replacement. They were, however, removed and the threads cleaned gently at 24,ooo km and at 82,ooo km.
Now at 100,ooo km and performing perfectly, I intend to change them at 120,ooo km when I do the next tappet check.
Macka
I only use Iridium or Platinum if specified by the manufacturer.
The standard copper plugs in my 700 were changed for the first time at 48,ooo km. They looked great and had never miss-fired.
Fuel consumption did not change after replacement. They were, however, removed and the threads cleaned gently at 24,ooo km and at 82,ooo km.
Now at 100,ooo km and performing perfectly, I intend to change them at 120,ooo km when I do the next tappet check.
Macka
Lubricating or failing to lubricate a thread contrary to specification, will result in misleading readings on a torque wrench. However, the instructions in the European Owner’s Manual circumvent the issue. Section 8 is significant.
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Coyote Chris
Site Supporter
What an interesting set of instructions! Completely different than from any US set of instructions. Almost like they are meant for the third world....Lubricating or failing to lubricate a thread contrary to specification, will result in misleading readings on a torque wrench. However, the instructions in the European Owner’s Manual circumvent the issue. Section 8 is significant.
Chris instructions.
Take new plug and check gap.
put a skosh to a tad of anti sieze compound on the threads.
Hand start and hand tighten with zero torque.
Put on torque wrench and tighten to the spec (about 9 ft/lbs.)
(In aircraft mechanics school, they did teach us about bolt torque setting for wet and dry threads. Forgetaboutthat with plugs and a new crush washer.)
Chris has hit the important point here. It is all about the crush washer. If the plug is too loose, the washer will not stop the exhaust gas (and carbon) coming up the threads. This results in build-up and corrosion of the threads on both the plug and cylinder head. There will also be insufficient heat transfer to the cylinder head from the plug, possibly resulting in pre-ignition. The plug will behave as if it is 1 or 2 heat ranges higher. A second correct tightening is very important.
Macka
Macka