Land Shark
SILVER Star
For reference when I replaced my plugs a coil a year and a half ago I torqued to 13 ft lbs and a few weeks ago I checked them and all but one or 2 were a small bit loose. Needless to say I torqued them more...
Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert!
- Thread starter 2001LC
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Bumping this to the top. Tightened my Denso iridium’s about six months ago to 13lb/ft and the ticking stopped. The ticking gradually came back so I changed them all this week with ngk ruthenium. Four were loose again so I torqued to 18ft/lb. Replaced the seals, boots, and springs on the four loose coils. Five of the plugs had scorching.
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mdcoa
SILVER Star
Just replaced the plugs on our new (to us) JDM 100. None were terribly tight—very easy to break loose. Two (cylinders 4 and 6, with 4 being the worse of the two) were not tight at all and the coil boots on those two had started to brown, so they were clearly not sealing well. Pic is of the #4 plug and coil boot.
Vehicle has just about 70k miles on it—these (Denso VK20) were probably the original plugs.
All that to say glad I did this very soon after purchasing!
Vehicle has just about 70k miles on it—these (Denso VK20) were probably the original plugs.
All that to say glad I did this very soon after purchasing!
2001LC
SILVER Star
- Thread starter
- #524
#4 & #6 are the two, I find loosen the most. #3 & #5 second most.
The factory installed Denso plugs, always say made in Japan. All I see today, purchased in USA from Denso distributor. Say: Assemble in USA. I did once buy a set of Denso, came by way of Mexico based on packaging. They also said made in Japan. I begged seller for more. No Mas!
The factory installed Denso plugs, always say made in Japan. All I see today, purchased in USA from Denso distributor. Say: Assemble in USA. I did once buy a set of Denso, came by way of Mexico based on packaging. They also said made in Japan. I begged seller for more. No Mas!
Ok, I have been searching every variation, with the coil part number and any other keywords I can think of....but you have a part number for this "boot and seal" kit?
Denso 671-8184
I used STANDARD MOTOR PRODUCTS SPP149E, and they were fine. If you are good with Amazon resale they have a "like new" set for $21. https://www.amazon.com/Denso-671-81...50103878&sprefix=denso+6718184,aps,137&sr=8-1
See this is what makes a good mod a great mod. Thanks @Trapper50cal. I actually bookmark many of @2001LC threads because they’re so thorough, and I had a vague memory of there being a cautionary tale around plugs, but I couldn’t remember. Thanks for pointing me the right way.
Not a mod but thanks for the compliment just the same. I just remember having to use a breaker bar to get my plugs out and sweating bullets that I wouldn't bugger up the threads in the head...scary stuff. Don't want that befalling anyone else if it can be avoided.
2001LC
SILVER Star
- Thread starter
- #532
I had one took 3 tank full of gas w/44K and 3/4" breaker bar. I too was sweating bullets. It wasn't the time I'd seen where anti seize was used on threads (bad idea). They walkout, and as the hot combustion gasses cooks anti seize, hardening and caking in threads.
lol you’re everywhere here so just assumed
I re-removed the ones I torqued to 13, wiped off the anti-seize, and put just a drop of motor oil on the threads instead. When fully dry, they really gall. Maybe new ones don’t, but I figure a drop of oil won’t cook like anti seize on mine, which have about 45k on them and look serviceable.
Torqued back in to 18, as you suggested @2001LC.
Jack90210
SILVER Star
A repost but a necessary add-on to this thread.
From NGK: 5 Things You Should Know About Spark Plugs
From NGK: 5 Things You Should Know About Spark Plugs
So I’ve read most of this thread and now know WAAAY more about plugs than I ever thought I needed to, but still a little confused.
1. Dry or wet? There seems to be consensus between this thread and manufacturer guidance, that applying anti-seize can lead to problems. But the galling that I observed with the NGK plugs in my engine suggests that a little lubrication will help avoid mechanical damage to the aluminum block threads. I used a drop of engine oil.
2. Torque? FSM says 13 ft/lb, mine survived 60+ ft/lb (too much obvs) and 18 ft/lb seems to be ok? However, even 25 ft/lb can be undone with a flick of the wrist, so does it really solve the problem identified at the top of this thread?
If the plugs were easier to access, it would be no big deal to re-torque at every oil change, but it’s easily an hour once you remove and replace all the stuff blocking the driver side coil packs.
1. Dry or wet? There seems to be consensus between this thread and manufacturer guidance, that applying anti-seize can lead to problems. But the galling that I observed with the NGK plugs in my engine suggests that a little lubrication will help avoid mechanical damage to the aluminum block threads. I used a drop of engine oil.
2. Torque? FSM says 13 ft/lb, mine survived 60+ ft/lb (too much obvs) and 18 ft/lb seems to be ok? However, even 25 ft/lb can be undone with a flick of the wrist, so does it really solve the problem identified at the top of this thread?
If the plugs were easier to access, it would be no big deal to re-torque at every oil change, but it’s easily an hour once you remove and replace all the stuff blocking the driver side coil packs.
2001LC
SILVER Star
- Thread starter
- #537
Lubing threads!! 
Very risking, even torquing to spec of 13ft-lbf. If threads lubed in any way. I've seen test on youtube. Of thread lubed, before torquing. They can be as much as 100% (double) over torque. So at 18ft-lbf lubed thread (anti seize or oil) you may be at 36ft-lbf.
Very risking, even torquing to spec of 13ft-lbf. If threads lubed in any way. I've seen test on youtube. Of thread lubed, before torquing. They can be as much as 100% (double) over torque. So at 18ft-lbf lubed thread (anti seize or oil) you may be at 36ft-lbf.
Could your galling be a consequence of your insanely overtorqued plugs?
Retorquing plugs every oil change seems like overcomplicating this particular issue. If you are concerned about thread health, run a thread cleaner before installing new plugs dry. Make sure your torque wrench is roughly calibrated, torque to 18 ft/lb, then change after 60k.
I listen to my truck for the tell-tale signs of these plugs walking out. If I heard even a hint of the tick tick tick I would plan to do plugs.
Retorquing plugs every oil change seems like overcomplicating this particular issue. If you are concerned about thread health, run a thread cleaner before installing new plugs dry. Make sure your torque wrench is roughly calibrated, torque to 18 ft/lb, then change after 60k.
I listen to my truck for the tell-tale signs of these plugs walking out. If I heard even a hint of the tick tick tick I would plan to do plugs.
When I removed these plugs for inspection, I used my torque wrench to REMOVE after I struggled with the first one. Wrench was set at 30 ft/lb and it clicked and required much more effort after the click. I’m estimating 50-60 ft/lb to break the grip and continuous 15-20 ft/lb to fully remove.Lubing threads!!
Very risking, even torquing to spec of 13ft-lbf. If threads lubed in any way. I've seen test on youtube. Of thread lubed, before torquing. They can be as much as 100% (double) over torque. So at 18ft-lbf lubed thread (anti seize or oil) you may be at 36ft-lbf.
Plugs are correct and look ok but plan is to replace with new and start fresh, with a dry install. My question is about the head threads, which maybe have been stressed:
1) how do you correctly chase them and avoid debris in the cylinder? I’ve read about making sure the piston is below TDC, greasing the chasing tap so debris sticks to it, blow gun, vacuum, borescope, etc. is it really that complicated?
2) what to look for to assess thread health? If the new plugs are going in smooth and dry, is that enough?
You use a thread back tap, like this one.
It's able to be inserted into the hole, then you expand the threads and run it back out slowly. It cleans the threads and brings any debris with.
I have used one for soot caked glow plug threads on VW TDIs.
