Replace spark plugs and wires, doing #8 the harder way, and then the hard way on a 2013 Escalade 6.2L

[skpyle]

Welcome to my misadventures in LS series engine Spark Plug Land!!!

It was time for new spark plugs and wires on my new-to-me 2013 Escalade ESV AWD 6.2L. It had 124,*** miles when I did this work. My goal was to get all the maintenance done, especially tune up items prior to datalogging for the Black Bear Tune.

I had been forewarned by a number of sources that #8 spark plug is a real pain to get to. So, in my infinite wisdom(remember that...) I decided to pull the inner fender liner and go in from the wheel well. I am used to that, as it was the only way to get to the spark plugs on my 1999 Explorer Limited 5.0L AWD. Plus, I was going to drain the radiator at the same time, and needed to move the inner fender liner anyway.

Pulling the wheel and fender line wasn't bad, though the christmas tree push pins for the MAF sensor cable were a pain to fully remove.



Fender liner removed and out of the way. My outside cats loved investigating it.




Open fenderwell to stuff my gorilla body into.




Necessary parts: ACDelco 748UU spark plug wire set for Flex-Fuel, eight ACDelco 41-162 Iridium spark plugs, and dielectric grease for the boots.



Figuring that, if I am going to be pi$$ed off at this, might as well get right into the bad one. I decided to start with #8 spark plug.





The dreaded #8 spark plug on a GMT-900. Can't even see it. And...because of the heat shield and bottom of the AC accumulator, I can't even fully get a hand on it. Yay.

By using a combination of dexterity, both sets of fingers, long needle nosed pliers, short pliers, spark plug socket, ratchet, other sockets, desperation, violence, and more than a few curse words, I got the boot off the spark plug and removed the spark plug.



Some of the tools required to R&R #8 spark plug.


Installing the new spark plug was only slightly less of a fiasco. Though I did drop the plug and socket down between the exhaust manifold and the engine. I was able to fish out out with a magnet on a stick. With the above mentioned dexterity, I got the plug started in the hole and threaded it in smoothly by hand. Amazingly, I was even able to get a torque wrench on it! 11 foot/pounds and that one was done.

 

[skpyle]

Truth be told, I pulled all four spark plugs and wires from the passenger's side before I replaced any. I wanted to get a photo comparing old to new.



Spark plugs and wires from the passenger's side, new at front, then starting with #2 and going to #8 at back.



New at left, starting with #2 then going to #8 at right. Burn looks OK, though I am told the LS engines in the GMT-900 trucks 'run hot.'
I am still learning about these. This is my first LS engine, and only my second fuel injected V-8.


All the old plugs had gaps between 0.043" and 0.045", which I found surprising. As well, all were ACDelco 41-110 plugs. To my understanding, those are OE fitment and no longer available. What I am leading up to, is these could be the original plugs, though the gaps seem awfully tight for 124,*** miles. Regardless, new plugs were installed.

I checked the gaps on all the new plugs, they were between 0.040" and 0.041". I installed them all dry and torqued them to 11 foot/pounds. While #8 was the worst, #6-2 were no picnic. Access was not fun. But I got them.

I then installed the new plug wires, with a swipe of dielectric grease in each boot. I listened for a solid CLICK as the wires seated in the coils and on the plugs. Oh yeah, I transferred the heat shields from old plug boots to the new plug boots.




New spark plugs and wires on the passenger's side. DONE



The driver's side went much smoother. Less curse words. I actually did them from the top, laying over the driver's side fender. I laid down fender mats and stood on a box to be able to lean in and get good access. Granted, #7 plug and wire were a stretch, but I got them.




Better access from the top for the driver's side. No need to pull the inner fender liner.



The driver's side spark plugs and wires mimic'd the passenger's side. All were ACDelco 41-110's with good burn and gaps between 0.043" and 0.045". New plug gaps were between 0.040" and 0.041". New plugs went in dry, torqued to 11 foot/pounds, new plug wires with heat shields transferred to the boots went on with dielectric grease in the boots.




Driver's side spark plugs and wires. New at front, #1 next going to #7 at back. #3 spark plug end terminal came off with the boot.


With that, replacing the spark plugs and wires was done. And I didn't want to have to do that again anytime soon.

Too bad it went wrong shortly thereafter...

 

[skpyle]

It was awhile before I started the engine, because I had to drain and refill the radiator. Once done, I started the engine and let it run to bring the cooling system up to temp. Engine started just fine. However, it seemed to me like it 'shook' more than normal at idle. Specifically, I could see the transmission filler tube moving side to side. Made a note and went on.
Dumba$$.

I got back in to find the check engine light on.
Shut it down and pull codes. One DTC. P0308. Those of you who know codes, know what this means.
P0308 is Cylinder #8 misfire.
Of course it is...

Not wanting to go through the effort of jacking the front end up, pulling the front wheel, and removing the inner fender liner again, I attacked from the top. I laid fender mats accross the nose and top of the front end of the Escalade, stood on boxes, and laid across the top of the driver's side of the still warm engine. With a kevlar sleeve on my left arm and a decent glove on my hand, I was able to squeeze it down to #8 spark plug from the top. The boot on the wire felt like it was still securely attached to the spark plug. So, maybe I didn't get the coil end of the wire seated properly. I removed and reinstalled the coil end of the spark plug wire in the coil. I felt it CLICK.

Cleared the DTC, restarted the engine, and waited. After awhile, the check engine light came back on. At this point, it was 9:30PM, I was pi$$ed, tired, and done. I parked the Escalade, and went in for the night.

After dinner, I did some google-fu on P0308. Have you ever googled medical symptoms, and most of them quickly lead to "you're dying"? Yeah...this was the same. I saw everything to intake manifold leaks to failed camshafts and lifters. OK, enough internet for tonight. I went to bed.

In the morning, I kept turning this problem over in my head. Occam's Razor: whatever is wrong, look at the last thing you did. This means it HAS to be something I did while changing spark plugs and wires. I went back outside, determined to figure out what I had done wrong.

Once again layering up the pads and standing on boxes, I was able to lay across the engine and reach down to #8 spark plug. I struggled with the long needle nosed pliers, but I finally got the boot off the spark plug. I pulled the wire out of the coil and got a good look at it. It looked fine. Soooo...it has to be the plug. Did I get a bad plug? Do I remove the plug and swap it to another cylinder and see if the problem follows? Do I dig one of the old plugs out of the trash and put it in?
Regardless of what I do next, #8 spark plug has to come back out.

Surprisingly, I had better access to remove #8 spark plug from the top than going in from the side. I was able to get #8 plug out and get a look at it.



Padding to protect the nose and top of the front end of my Escalade.




Simple yet relatively ingenious stand for me to get access to the engine.




Relatively straight shot down to #8 spark plug. See that very out of focus slightly rusty stud on the AC line connection at the accumulator? I am pretty sure I have a scar in my left forearm from this. Next time I do spark plugs and wires, this will get covered by a rubber cap or something. It is RIGHT in the way of my arm.



Sooo...I pulled #8 spark plug. And immediately found the problem.



Do you remember when I said I dropped the spark plug and socket behind the exhaust manifold the first time I tried to install it? Once I retrieved it, I just installed it. I never examined the plug. Dumba$$. I would have seen that when it fell, it landed on the side electrode and closed the gap.


While this is bad, it was the smoking gun I was looking for. I knew this was the problem. I carefully regapped this plug to 0.041", reinstalled it, reinstalled the spark plug wire with fresh dielectric grease in the boots, and cleared the DTC.

I hit the key, and the engine fired right up. Idle was smoother, and the transmission fill tube was no longer shaking side to side. I went for a drive...and no check engine light.
So, as I had surmised, this was a self induced issue. But, at least I figured it out.




#8 spark plug regapped to 0.041". Worked much better after that...

 

[George B]

Reaching number 8 from the top is best. The NNBS is easier than the NBS too. Most of us use the plug socket with the hex on the back and then use a short socket on that hex. Works like a charm.

 

[Bill 1960]

Nice write up, that #8 is the cause of many swear words for sure.

 

[skpyle]

Reaching number 8 from the top is best. The NNBS is easier than the NBS too. Most of us use the plug socket with the hex on the back and then use a short socket on that hex. Works like a charm.

I have definitely learned that!

Nice write up, that #8 is the cause of many swear words for sure.

Thank you!

 

[gooffeyguy]

I did my plugs in September of 2019 and I was able to get the 41-110 plugs, so they may or may not be the originals

 

[skpyle]

I did my plugs in September of 2019 and I was able to get the 41-110 plugs, so they may or may not be the originals

That makes sense. I want to think that they were original, but the gaps were just too tight.
Thanks!

 

[pwtr02ss]

Excellent write up again. That number 8 plug is a pita. I bought the Matco spark plug socket set for that specific plug. It's not bad on the avalanche as it doesn't have rear ac. The suv on the other hand, those lines make me say bad words. Glad you were successful in yet another venture of r&r on the caddy!

 

[skpyle]

Excellent write up again. That number 8 plug is a pita. I bought the Matco spark plug socket set for that specific plug. It's not bad on the avalanche as it doesn't have rear ac. The suv on the other hand, those lines make me say bad words. Glad you were successful in yet another venture of r&r on the caddy!

Thank you, sir!
I am learning. One step at a time...