removed stuck spark plug - cln oil on head threads ?

Post by **BobbyC777** » 18 Sep 2024, 22:14

I am doing an overdue spark plug change on my 2004 V70. One of the plugs was stuck but I used Kroil oil to help get it out. Should I try to remove the oil that has run down into the plug threads in the head or just forget about it? If I should clean it, any suggestions how? Brake cleaning fluid and compressed air or ..... ?

Thanks!

Post by **scot850** » 18 Sep 2024, 22:44

I use a thin strip of cotton clothe wrapped around a flat blade long screwdriver soaked with WD40. If you want it really clean, then do the same with brake cleaner.

On refitting the plugs, there is often debate on using sparkplug thread ease or not as it alters the torque on the plugs when tightening.

I've used this for years on my cars and no issues or stuck plugs.

Neil.

ignatz · Post by **ignatz** » 19 Sep 2024, 03:16

I use gun cleaning rods and cotton patches. Just use a long enough rod!

Post by **cn90** » 19 Sep 2024, 06:40

For old spark plugs...I turn it just 1/2 turn (180 degrees) then stop and spray PB Blaster down the hole and let it soak for 5-10 min.
Then turn the socket CW and CCW a few times to avoid stripping the threads.

Once the plug is out, there might be a bit of PB Blaster in the cylinder, it will be burned anyway. If you are concerned, then use a long piece of cloth (cut it small like a wick) + long screwdriver and push it down to absorb the fluid.

On installation, I always use anti seize (the equivalent of one drop). It makes things much easier at the next plug job.

Post by **BobbyC777** » 19 Sep 2024, 07:24

Thanks for tips. This anti-seize vs. no-anti-seize is almost a religious thing. I have Bosch plugs and they say they are coated and no anti-seize is required. But I still like the idea of using a very small amount. With the amount of miles on the car (224K) and on me, I probably won't have to worry about changing plugs on this vehicle again!

I asked about cleaning the oil from the head threads as I figured the lubricant (used to help get it out) might cause the plug to go in deeper before my torque wrench clicked. Torque values is another area with many different figures offered.

Post by **cn90** » 19 Sep 2024, 08:22

I never clean the threads unless necessary.

I use anti-seize and ~18 ft*lb for years, zero issues.

Post by **erikv11** » 19 Sep 2024, 11:46

IMO it doesn't matter either way if you are careful in your work.

I would clean the threads if any penetrant or oil got in there. I like the spark plugs tubes to be spotless. Use compressed air to clean them out before I pull a plug. I never use anti-seize on spark plugs. Zero issues ever.

The recommendations against using anti-seize for spark plugs are made in order to prevent misleading people who may be less careful or less experienced. Which makes them good recommendations in general, but they are what they are.

Post by **BobbyC777** » 19 Sep 2024, 12:14

Well, the job is done! And it started and ran! Thanks for all the suggestions and support.

AFTER I had finished the job I saw in the Owners Manual that the spark plug torque should be 25 Nm (18.4 ft. lb). But they also specified Champion spark plugs! I used Bosch.

And it gave me the excuse to buy a new torque wrench (Suercup) whose range (5-45 ft-lbs.) is better for jobs like this than the much bigger one I have for lug nuts, etc.

BTW, I did not remove either the big cross bar or the turbo pipe. Not sure I saved any time by skipping this as it made some access challenging.

Thanks!

Bob

Post by **cn90** » 19 Sep 2024, 12:19

- Some ppl in BMW forum reports galling when removing factory plugs at 100 K miles. Some even stripped the aluminum threads. Have not heard that in Volvo forums yet.

- Every time I remove the factory spark plug, I hear the scary screeching sound and it is on very stiff. This is why I usually crack it 1/2 turn, then PB Blaster and on installation, I use anti-seize. At the next plug change, it is a breeze with anti-seize.

Post by **firstv70volvo** » 19 Sep 2024, 12:27

BobbyC777 wrote: ↑19 Sep 2024, 07:24 Thanks for tips. This anti-seize vs. no-anti-seize is almost a religious thing. I have Bosch plugs and they say they are coated and no anti-seize is required. But I still like the idea of using a very small amount. With the amount of miles on the car (224K) and on me, I probably won't have to worry about changing plugs on this vehicle again!

I asked about cleaning the oil from the head threads as I figured the lubricant (used to help get it out) might cause the plug to go in deeper before my torque wrench clicked. Torque values is another area with many different figures offered.

NGK says to reduce torque tightening spec by 30% when using anti-seize, I use copper based anti-seize (Permatex recommends using this type of anti-seize for aluminum heads) and I follow this torque and anti-seize type advice. The only problem I've ever had removing plugs is because of the carbon build up on the end of the plugs that extends into the combustion chamber, the carbon causes resistance in the threads when backing out the plugs. CN90 advice of loosening the plugs by 1/2 turn, using penetrating oil and working back and forth helps with plug ends that have the carbon build up.

https://www.ngk.com/ngk-plug-torque-settings