Spark plugs and wires

[Snacky]

I understand the plugs are supposed to be good to 100K. I'm at 85K and think I'd like to just go ahead and replace them. I've read some conflicting information. What was the gap on thee stock plugs for an 07? What I hear is that the gap gets larger over time. What is the gap GM is reccomending now? It's a smaller gap now right? Or is that just for the earlier motors. I also read that you don't want to change the gap caus you can break the iridium tip so you want to just buy ones with the gap you need.

Is there a good iridium plug with the proper gap I could get at one of the local parts stores?

Also, plug wires, is that something we no longer need to replace with these trucks since they come straight off the coil as I understand it?

 

[992dr]

Here ya go

Spark Plug Wire Resistance
397-1,337 ohms

Spark Plug Gap
0.040 in English

Spark Plug Type
GM P/N 12571164
AC Spark Plug P/N 41-985

Don't forget to put a little dap of anti seize on the threads.
Hope this helps

 

[Snacky]

Went ahead and changed them out today at 83K. Definately some carbon build up around the inner base of the plug but electrode thingy didn't look too bad. Hard to say if it's running any "better" but she definitely runs STRONG! Number 8 was a ***** like others have said but I found the secret recipe. I took The six short bolts out that hold the aluminum heat shield thing in. I wasn't able to completely remove it from the engine compartment but was able to move it out-of-the-way enough to make a huge difference. Then, two universal joints and several extensions did the trick. I used AC 41-110, that's what they reccomended at Advance. The stockers were 41–985. Any difference, did I F up putting in the 41-110? Website says it is an exact fit...

 

[992dr]

Haha, no you didn't f-up.
Now that I think about it, I used the 41-110 to.
Did you check the gaps to make sure they were all to spec?

 

[Snacky]

Haha, no you didn't f-up.
Now that I think about it, I used the 41-110 to.
Did you check the gaps to make sure they were all to spec?

Cool thanks... I did

 

[ccapehartusarmyINF.(ret)]

i replaced the plugs in my 02 at 100k and the old ones still looked pretty good
they had a light rusty reddish tint to them though someone told me it was an additive that chevron uses that causes it and i do fill up there often ?

 

[Big Buttons]

I replaced the plugs on my 2001 YXL at 100K and they still looked pretty new. I just hit 100K in my 2002 Burb so I will be changing the plugs soon. I don't think they will be too bad either.

I went with ac delcos in the YXL, will be going with NGK TR55s in the burb.

 

[1BADI5]

GM has a service bulletin with an update on the gapping on new plugs.

IF memory serves me right the gap spec went from .060 to NOW .040

I went with new AC Delco IR plugs and MSD SuperConductor 8.5MM wires.....nice difference in seat dyno LOL

 

[meadows.harrison]

What is the trick to getting at cyl 8?

 

[ezdaar]

Lubricate the firewall, AC moisture plate thing and side of engine with blood.

That usually works for me.


LOL!

Grab some sand paper or flat file. and round the edge of that aluminum catch pan below AC part near #8, its razor sharp from being stamped. so be carefull.. make it as dull as a butter knife..

Grab your socket, 4" extension and a swivel.. May not need the swivel or extension. Been awhile and I have forgot..
either way, Sack up and take that plug out.
Once you do it and figure out exactly the angles needed. its gravy from then on..

GL

PS, you wil need a socket wrench as well