GMC Truck Forum banner

1 - 9 of 9 Posts

·
Putting things in places
Joined
·
102 Posts
Discussion Starter #1
Doing 100K PM on a suburban and AC Delco doesn't offer .060" gap plugs for those motors even though the engine ID sticker AND service manual both specify .060?
 

·
Registered
Joined
·
47 Posts
I must have missed something. I never knew plugs came with a specific pre-set gap. I've only been working on stuff for 40+ years, and always had to set the gap on new plugs to the auto manufacture's recommended gap.
 

·
Putting things in places
Joined
·
102 Posts
Discussion Starter #6
Hey Nicholas, go spend $6 on a ac delco iridium and try to gap it. :) one of two things will happen, you'll either bend the electrode cause it's thin as hell, or you'll knock the iridium disc off the ground strap. If you don't knock it off, it'll loosen up and come off in your combustion chamber sometime...

I still haven't figured out why they changed. If you go to the ac delco site and look up the plugs, you'll see they state .040" gap with a big azz side note, DO NOT CHANGE PLUG GAP!
 

·
Registered
Joined
·
24 Posts
Tighter gaps require less energy to fire. Often results in smoother idle and better tip in. You only NEED enough ignition energy to fire the plug, anything more just builds excess heat in the coil and premature failure.
 

·
DisgruntleD
Joined
·
3,823 Posts
I must have missed something. I never knew plugs came with a specific pre-set gap. I've only been working on stuff for 40+ years, and always had to set the gap on new plugs to the auto manufacture's recommended gap.

Almost all plugs are pre-gapped in newer vehicles, and trying to gap them yourself ruins them.

I just put some NGK TR55IX plugs on the wifes avalanche and they were gapped to .060.
 
1 - 9 of 9 Posts
Top