Spark Plug Boot Removal


#1

My plugs are overdue for replacement (I have about 50k miles on them). I managed to replace two of the rear three spark plugs in my 1992 Buick Century (V6), but not the third (plug #2). The rear boots are encased with a metal sleeve, but not the front boots. Is there any special tool required for pulling off the boots without damaging the ignition wires? Are there any special techniques for removal? I know I should replace the plugs themselves when the engine is cold, but will the boots slip off more easily if the engine is still a little warm? I didn’t have this much trouble in the past. Could keeping them in so long caused the problem? My left arm is still sore from trying to remove the #2 boot. Any advice will be greatly appreciated. Thanks.


#2

There’s a tool called a “hose pliars” the looks like a long needle-nose pliar with rounded and 45 degree angled tips. Those are the best tool I’ve used. Harbor Freight Tools sells them, as do most automotive tool stores, but they’re not common in other stores.


#3

There are a variety of spark plug boot pullers available. You just need to figure out which puller will work the best for your application.

Tester


#4

Also, do not try to pull the boot straight off. Use a back and forth twisting motion as you pull.
While the boot is off inspect the terminal inside for any corrosion.

Be sure to reinstall those metal shields as they protect the boots from the exhaust manifold heat.


#5

When you replace the boots, be sure to coat the insides with some silicone dielectric grease. It will help to keep them from arcing and will make them easier to remove in the future.


#6

A very handy boot removal tool from long ago was made by attaching a very small diameter tube to an air nozzle. It could be pressed down between the boot and wire and air pressure would separate the boot from the plug and then blow it free.


#7

Agree with everyone else. Those can be a bear. The metal shield though just fits over the boot and nothing special. What I have used is a very long needle nose, like a 12" from Checker for about $10. They have straight and bent. Don’t remember which one I got but I should have gotten the other one. Allows getting a grip on it and still have some leverage to pop the boot off. Just as much problem getting it back on again. Might want to consider changing the wires at the same time instead if its been that long and for sure use the dielectric on the inside next time.


#8

Every time I change plugs I also change wires. Don’t use Channellock pliers, it will smash the tubes and get them out of round. Also, just as OK4450 stated. Twist them back and forth and don’t pull them straight off.

Some will disagree but I apply a little anti seize to the threads and lower portion of plug. Also apply dielectric grease to the inside of the boots (as Keith said). It will save some bloody knuckles in the future.


#9
Every time I change plugs I also change wires.

I’m of the belief you NEVER have to change wires. Have owned 4 vehicles with plugs that have well over 300k miles on original plug wires as proof.

Every couple of months get a damp cloth and clean them. They should last the life of the vehicle.


#10

“… I apply a little anti seize to the threads and lower portion of plug.”

DON’T DO THAT!


#11

I use anti-seize on all of them and I don’t think that the anti-seize itself is the cause of any problems. The problems are caused by those with canned hams on the end of their arms who attempt to ram the plugs in as tight as they can get them.

Another lesser issue is that the installer may think that more is better and glob the anti-seize on which in turn may contaminate the tip of the plug.

Just like the installation, a little moderation with the chemical works well.


#12

It looks like NGK plugs are made weaker than the “black” ones they show in your link. Don’t know if that impresses me or not. Having said that, my Honda shop manual specifies NGK plugs AND anti-seize to the threads, but only 13 ft-lb torque.


#13

Both DENSO and NGK iridium plugs are OEM on Honda. Honda seems to use them interchangeably, sometimes even having both types on the same engine as it comes from the factory.

I know Honda shop manuals recommend 13 lb-ft and anti-seize, but both DENSO and NGK recommend 18 lb-ft and NO anti-seize for first-time installation of 14mm Ø plug threads. Perhaps 13 lb-ft with anti-seize is equivalent to 18 lb-ft without anti-seize. Whenever manufacturers’ and car-makers’ specs differ, I always go with the manufacturers’. Honda had some problems with spark plugs becoming loose in the past and may have issued a Tech Bulletin.

Funny you should say NGK plugs are made weaker. Both DENSO and NGK are considered premium plugs.


#14
Both DENSO and NGK iridium plugs are OEM on Honda. Honda seems to use them interchangeably, sometimes even having both types on the same engine as it comes from the factory.

Same with my 4runner. Left bank came with Denso, and the right bank came with NGK.

Honda shop manual specifies NGK plugs AND anti-seize to the threads, but only 13 ft-lb torque.

You do NOT use anti-seize on NGK plugs.


#15

I always used anti seize around the threads and a gob of dielectric grease into the boot of the wire with no problems. And, while Im a big supporter of using a torque wrench for most things, I never used it for spark plug changes. Always screwed them in by hand and then snugged it until it felt right


#16
I always used anti seize around the threads and a gob of dielectric grease into the boot of the wire with no problems.

Were they NGK plugs? Other plugs are fine. If you use anti-seize on NGK plugs you have to be real careful. And I don’t see a need for it since the NGK plugs are plated. I haven’t used anti-seize on plugs since NGK started plating their plugs and never had a problem.


#17

@MikeInNH‌ I dont remember if they were NGK or not. Im sure theyve passed through my hands at one time or another. Ive had too many scenarios where plugs are damn welded in and nerve racking to unscrew. Same with old spark plug wires. Its easiest to use it and ensure ease of removal the next go round. To each his own I guess, but i’ll continue using anti-seize on the threads. A little dab’ll do ya as they say.


#18
To each his own I guess, but i'll continue using anti-seize on the threads. A little dab'll do ya as they say.

Just be careful with NGK plugs so you don’t over torque them.


#19

If you read both pages of the link to NGK, it does recommend anti-seize on plugs that are not plated. You also have to use anti-seize on any plug that you are reusing as the plating is a one time deal. I used to be a big fan or torquing everything, not so much anymore, especially spark plugs.

I do not have my Honda FSM anymore so I can’t verify statements above but sometimes you have to read the instructions very closely. It may specify one procedure for reinstalling the old plugs and a different one for installing new plugs.

I remember back when spark plugs came with more instructions on the package than they do now. They used to give two different procedures for installation, one for the first time and a different procedure for reinstalling after cleaning/sandblasting and re-gaping (AKA minor tune-up, how many remember doing that?). The old procedures used what we call a torque angle method today and I have gone back to that.

Now when I change plugs, I use the following steps.

Use compressed air to clean around the spark plug before removal if the plug is not in a sealed hole.

Remove plug.

If not plated, put anti-seize on the threads, small amount and avoid getting anywhere near the tip where it could cause a short circuit around the electrode. Keep it in the threads only.

Install until the threads bottom out. Use a torque wrench to turn the plug the recommended degrees. For a plug with a gasket, that is usually 3/4 to 7/8 turn (270-315°). I like using the torque wrench just to make sure I don’t exceed the specified torque, can’t be too safe. Beam type torque wrench is the best for this.

Goop up the sparkplug boot with dielectric grease and install. I will even coat the outside of the boot for a little ways up just incase the boot were to split later and sometimes put a little around the wire where it enters the boot, just in case.


#20
If you read both pages of the link to NGK, it does recommend anti-seize on plugs that are not plated.

ALL NGK plugs are plated now.