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hey guys, thought id post my old spark plugs on here and "spark" up some conversation :lol:

Most plugs look like they have normal wear, except one. Then two others look a little more worn.

Cylinder 1 (AFM)
IMG_4064.JPG


Cylinder 2
IMG_4065.JPG


Cylinder 3
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Cylinder 4 (AFM)
IMG_4067.JPG


Cylinder 5
IMG_4068.JPG


Cylinder 6 (AFM)
IMG_4069.JPG


Cylinder 7 (AFM)
IMG_4070.JPG


Cylinder 8
IMG_4071.JPG


As you can see, plugs 1, 6, and 7 have clearly been used more due to AFM. Plug 4 however looks as normal as the others.
Plug 7 is interesting to me. I am surprised to see it have so much carbon fouling.
Can sticky lifters cause this? Every now and then I hear a tick when i crank up cold, but it doesn't last long. I know these engines are know for lifter issues.

Anyways, the plug change went well. I got all the plugs and wires changed and replaced with orginal AcDelco parts (41-110 plugs and 748UU wires) along with anti-seize and dielectric grease. I haven't noticed much change in MPG, but it makes me happier.
 

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Interesting, Does it run any better or about the same? May be the ring issue but doesn't look that bad at this point. May want to add some MMO just in case and keep a check on it. How does the oil look? I've notice mine is going to V4 more often than it seem to before. I need to make a decision on it soon. I noticed in some GM bulletins that putting in M5 will not allow AFM to activate. Mine(11) does... Does yours? I would think you could hear the lifter while running if its not opening the valve. Mine is perfectly quiet at startup idle but starting to hear a slight noise around 1800 rpm.
 

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I would consider disabling AFM.
Just remember that the valves and rings will have a similar appearance to the plug and they could eventually stick or gum up.
Disabling the AFM will help burn that crud out and help to prevent it. It's a cheap fix. It doesn't look that bad yet.
It might go another 100k but then again.....
 

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You bet, nothing is written in stone. There's a ton of different factors involved in a running motor.
Some are more obvious to start looking at but that doesn't mean it's the cause. You gotta start somewhere.
 

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Discussion Starter · #7 ·
apcnc said:
Interesting, Does it run any better or about the same? May be the ring issue but doesn't look that bad at this point. May want to add some MMO just in case and keep a check on it. How does the oil look? I've notice mine is going to V4 more often than it seem to before. I need to make a decision on it soon. I noticed in some GM bulletins that putting in M5 will not allow AFM to activate. Mine(11) does... Does yours? I would think you could hear the lifter while running if its not opening the valve. Mine is perfectly quiet at startup idle but starting to hear a slight noise around 1800 rpm.
I feel like it runs about the same. No significant increase in power, response, or gas mileage, but i know its good to have them in. I dont have the DIC in my truck so i dont know when it is in V4 mode. In fact, i didn't think i had AFM until i found this site because i can't check the mode in my truck. I dont think im going to deactivate it yet. Im hoping for the best as long as i continue to take good care of it.
 
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