K20 (320k km) under valve cover + spark plug pics, how to clean threads and spark plug tube oil leak?

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Oct 8, 2012
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Ontario, Canada
Time to do another valve adjustment(every 160k) and spark plug change on K20 with 320k+ km.
PP 0W20(winter), 5W30(summer) and sometimes a mix of the two(left over oil from unused jugs) + Fram Ultra(every other oil change)
MM usually indicates 10% oil life left around 10-12k km of driving.

Compared to 160k pics, no obvious difference under valve cover.


Spark plugs remain at 0.040 gap, will put new Denso TT spark plug in.


2 questions:




1. I did not replace the spark plug tube seals last time. From these pics, seems like 2 have a little oil leak?
2. I stupidly applied a bit of anti-seize last time when installing new spark plugs. It did make removal a bit rougher. Is there an easy way to clean up the threads a bit?
 
I too have found that anti seize on Honda heads make the plugs a scary deal to remove. But once they're out the new ones go in like a dream, so I've never worried about cleaning up the threads.

As for tube seals, that corrosion on the plugs isn't from that. If the seals were truly leaking there would be oil around the hex portion of the plugs. Still, they're not terribly expensive and if you didn't do them last time, just go ahead and do them this time along with the grommets on the cover and you'll be good to go.
 
Time to do another valve adjustment(every 160k) and spark plug change on K20 with 320k+ km.
PP 0W20(winter), 5W30(summer) and sometimes a mix of the two(left over oil from unused jugs) + Fram Ultra(every other oil change)
MM usually indicates 10% oil life left around 10-12k km of driving.

Compared to 160k pics, no obvious difference under valve cover.


Spark plugs remain at 0.040 gap, will put new Denso TT spark plug in.


2 questions:




1. I did not replace the spark plug tube seals last time. From these pics, seems like 2 have a little oil leak?
2. I stupidly applied a bit of anti-seize last time when installing new spark plugs. It did make removal a bit rougher. Is there an easy way to clean up the threads a bit?

Without the anti seize they may have been much more difficult to remove, use the anti seize. NGK has this to say..

" NGK tech support has received a number of tech calls from installers who have over-tightened spark plugs because of the use of anti-seize. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage."

Understanding their motive for publishing this is clear, they don't want to be held responsible and possibly sued for damage when installing plug to manufacturers specified torque. Secondly there is a much bigger can of worms they do not want to open and that would be the one from EPA when cats are damaged from misfires due to bone heads lathering up the threads of the plugs and shorting it.

It is not that the coating prevents plugs from seizing, while it certainly hinders thread binding it does not prevent it, I have removed a lot of NGK coated plugs that were extremely difficult to remove. The problem occurs more in climates where there are a lot of cold starts in colder temps where the engine is cold for a longer time creating more moisture and carbon to form in the threads from the combustion chamber side.

Reduce the torque by 20%, coat the threads with a very thin coat of the compound keeping it away from the firing end and you will never have a problem.
 
I too have found that anti seize on Honda heads make the plugs a scary deal to remove. But once they're out the new ones go in like a dream, so I've never worried about cleaning up the threads.

As for tube seals, that corrosion on the plugs isn't from that. If the seals were truly leaking there would be oil around the hex portion of the plugs. Still, they're not terribly expensive and if you didn't do them last time, just go ahead and do them this time along with the grommets on the cover and you'll be good to go.

Compared to the other car where it was factory installed spark plugs with 276k km and no anti-seize were on there. It was a lot easier to remove than this one.
I will go with no anti-seize this time.

I checked the tube seals and they don't seem to be ripped.
Last time when I did this, I had new tube seals, but I couldn't seem to be able to pry the old one out.
Do I just use flat head screwdriver?
Any easy way to push the new seals in without some special tool?
 
I spray a little WD-40 down the plug hole to clean the threads.
Plugs get a slight brush of anti-seize.
Spin em in by hand using a rubber plug installer.
If there is any resistance, I stop and figure what's wrong.
Finish with torque wrench set at reduced torque.

I have removed too many plugs that required far too much torque to remove.
 
Spark plug tube seals usually come with the valve cover gasket.

I thought you only had to adjust the valves if they're noisy



Denso also says no anti-seize


The problem with that is, tight valves don't make noise. You don't want overly tight valves. Especially since you're in there, there's no reason to not at least check them. Its super easy, especially on the I4 motors.

As for getting the tube seals out, yep just pry them out with a screwdriver. Usually they go flying across the shop. Sometimes they're stuck in there really well. As for installing, just the appropriate size socket, pipe, etc. Whatever you have that fits around the edge to drive it in. I'm sure you could use a press if you're so inclined and have one. I just use a socket and hammer. Never an issue.

Just make sure you put them in the right direction. The very first time I did a set I wasn't paying attention and put them in upside down. Spent 30 min cursing Honda trying to get the valve cover back on until I realized my own stupidity.
 
Spark plug tube seals usually come with the valve cover gasket.

I thought you only had to adjust the valves if they're noisy

I do have the seals, just looking for easy way to take old one out and put new one in.

Noisy or too quiet.
Like last time, intake side got loose.
Exhaust side got tight.
 
I checked the tube seals and they don't seem to be ripped.

Its not that they rip, its that they harden up over time and don't seal properly.

I have always wondered how bad they would need to be before they would leak oil in there. Looking at how Honda designed it, the tube sits way up near even with the valve cover, so its a fair long way for any quantity of oil to get up there and back down the tube. But I usually replace them anyways since I'm in there and I have V6 cars that are a little more work to get to.
 
@wing0



Jump to 13:30.

According to EricTheCarGuy, you might want to check the thread on the tube as well. It might be the source of leaking.


Thanks. I watched that video a long time ago. Good refresher.

I'm done with valve adjustments and spark plug installation.
My rtv silicone tube dried out, so I have to go pick up another one in the morning before I can put the valve cover back on.
 
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