Issue With Spark Plugs

dclark369

Original poster
Member
Oct 19, 2021
6
Tulsa, OK
I went to change the spark plugs on my Trailblazer for the first time the other day. I had first read every thread and watched every video I could find to prepare. From what I could tell this was going to be a relatively easy thing to do. However, when I went to remove the induction coils I found that they would not come off. I tried pulling them off like I saw in the videos, it looked so easy with the guy reaching in with one hand and pulling them off after unscrewing the bolt. I thought I was going to damage the boot with how hard I was yanking on this thing. It would not budge. It is as if they are glued onto the spark plug. Is there some kind of trick I'm missing here? Do I need to push, then twist, then pull or something like that? Anybody have any suggestions on how I could get these things off? I would rather not have to buy new induction coils as these seem work fine and they are depressingly expensive. Any help would be appreciated.
 

Mektek

Member
May 2, 2017
656
FL
Presuming they've been on for many years, engine heat can fuse the rubber to the plug. Twisting the coil a bit while pulling should help loosen it, but it's not normally required to remove it.
 
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christo829

Member
Dec 7, 2011
497
Fairfax, Virginia
As Mektek said, sometimes the rubber sticks to the plug. On my #6 plug, I had to pull up on the coil and use a small seal pick to get the boot to start pulling loose. All the others I could get enough of a hold on to get a good turn and pop the boot loose.

When I put the new plugs in, I put a thin film of dielectric grease on the insulator to
help keep that from happening again. One drawback to doing that is that sometimes, if the seal is good enough on the boot, it traps air, which tries to push the coil back off the plug, and can keep the internal spring from seating properly on the spark plug. I had misfires on #3 afterwards because the coil hadn't clipped back down on the plug completely.

If you're using new coils, a lot of them have a slight coating already on them.

Good Luck!

Chris
 
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flyboy2610

Member
Aug 24, 2021
460
Lincoln, Ne.
And don't use cheap plugs from the clearance rack at Billy Bob's Bargain Barn! These engines are picky about spark plugs! Use original equipment GM plugs if at all possible.
 

dclark369

Original poster
Member
Oct 19, 2021
6
Tulsa, OK
I guess I'll just have to keep trying with twisting and pulling and hope I can get these out in one piece. And yes, I did make sure to get OEM plugs from ACDelco and dielectric grease for the boots. Thanks for all the help.
 

christo829

Member
Dec 7, 2011
497
Fairfax, Virginia
If the boots do break, you can get replacement boots and springs without springing for a whole new coil. Rockauto carries them (but obviously you'd have to wait for those to ship), and so does Advance Auto and AutoZone, so hopefully you've got a similar parts place near you that can supply any you might need.

Cheers-

Chris
 
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JerryIrons

Member
Dec 20, 2011
434
I guess I'll just have to keep trying with twisting and pulling and hope I can get these out in one piece. And yes, I did make sure to get OEM plugs from ACDelco and dielectric grease for the boots. Thanks for all the help.
You'll get them out keep trying.
 
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Dec 5, 2011
574
Central Pennsylvania
I almost always apply a thin coat of the plug boot crease you can get in the little packet at the parts store counter or vaseline, it's basically the same thing.
Also, only ever use genuine ACDelco 41-103 Spark plugs.... and verify their authenticity. Gapping is completely unnecessary if they are authentic.
Do not remove the hold down bolt from the coil or the spark plug itself if the head is "hot".... or even "warm"..... it's aluminum and may not like steel threads being twisted inside it. I've never had an issue doing so, but lots of people will pontificate on NOT doing this.
I also use never-seize (completely personal option - a lot of people disagree) on the coil hold down bolt.
Genuine ACDelco plugs have a coating (it might be the metal electroplate) that prevents the plug from seizing to the head altogether - that's also why thy say never to uninstall and reinstall the same plug, but I have after applying the tiniest bit of never-seize (again, a lot of people would give me grief for that).
As for removing the coil/boot.... I've honestly never had a real issue doing so. I've had to persuade the coil to come out using a small pry bar, but not much more than that.
Oh, and "wash" your coil gaskets with warm soapy water and dry them thoroughly. Then apply a light coat of vaseline.... it helps keep water out of the plug well and will prevent sticking next time.
 

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