I'm right at 6'0" and I can just barely reach and clean the windshield, much less the plugs
That spot right at the center of the windshield above the mirror
Damn that Adventure Package

 

Well I got drunk the other night........real drunk apparently, My wife asked me what I was getting my clothes on for and I reply that I was going to work on the Hummer (10pm). She replied.....okay. A short while later she said I came in all pissed off and stated that all 4 tires were flat and that I needed a straw. Thinking that our vehicles had been vandolized my wifewalked out in the yard to find the Hummers sleeping just fine with NO flat tires. The big garage door was shut but she could hear me fumbling around in there dropping tools. By now my wife thinks I'm just nuts and prob. checked around to be sure that the guns were locked up. She goes back in the house, through the kitchen into the garage to see if I found the straw I was looking for and I'm sure to check on my safety. She finds me laying on my stumach with my daughters remote controled Hummer sitting on a brick to get the tires off the ground. I was still fussing about the tires being flat. She looks at me said "Your a drunk retard, If you use the jack you wont have to lay on your f***K*nstumach" She then went back to watching tv. She shold have taken a picture.

 

So Chuck, when you woke up sober in the morning did you look in the garage to see if you screwed anything up?

 

I some how made it back tomy lazyboy and woke up wondering why the dog was avoiding me and how a straw got in my beer.

 

Wow, to have so much fun and not be able to remember! Do you think you had sex with the dog?

 

Guys, when I was looking, I didn't have much luck finding instructions, so I thought I'd document it when I did mine and help someone else. See my photo gallery for descriptions on each photo of what I am going describe.

First off, it's a very easy change with 2 things to look out for. One, make sure that when you do get the old plugs out that you compare the overall length to the new ones. I had originally bought Densos specified for my vehicle and they could have potentially caused a misfire because they are about an 1/8" shorter. With the Delphi ignition modules that control the plugs, contact is made by a spring, similar to a flashlight battery. There was no spring load when I replaced the first one which set off a red flag to me. I checked and the shorter length was the cause. I ended up using AC Delco iridiums OEM equivalent (111K on the 1st set, I'm not complaining).

Second item is on the front most cylinder, the wireway on the wiring harness has to be moved out of the way to remove the module. This is done by removing the snap on cover from the wireway. Removing the passenger side fastener holding it down is enough to access the module. Use a flat blade screw driver to rotate the plastic fastner down through the slot below it like a screw thread.

That being said, the change is pretty simple.

Remove the 2 screws holding intake plenum down on the passenger side. They are 10mm hexheads. Next, loosen the 4 hose clamps holding the air filter hose and intake supply hoses in place. I removed both hoses to make it easier and allow me to clean, but this could be optional. The plenum is then loose and can be lifted off. There is a drainback hose in the rear on a ****** fitting, but it pulls right off. Just make sure to replace it during reinstall.

Now the 5 ignition modules are visible. They are each held in place with a 10 mm hex head (I guess someone at GM was thinking, because the tools required are minimal). Once the bolts are loose the module slides straight up and the boot comes off of the spark plug. Things at this point look familiar. Gap, anti-seize and replace the plugs and replace the parts in reverse.

Please do remember to check the plug length. I read about one guy having misfires after changing his plugs and I fear the length is the reason. Good luck.

 

What type of spark plug did you use? OEM?

 

I apologize. I'm an engineer and use terms that I assume everyone else knows. OEM is a term for original manufacture parts. The spark plugs I ended up using were AC Delco 41-103 iridium. They are the 'newer' version of what was stock from what I can tell. Dimensionally they are identical. Gap them to .043.