So I've read up on past threads. I see that ONLY OEM plugs are recommended. But maybe that's not my issue? Replaced OEM plugs with NGK over the weekend, they look identical to stock. Noticed that there is a wire track that is in the way of the first coil in the line. Made it tough to get the coil off and back on. When I reinstalled the coil on this one it seems like I was forcing down rubber to get it bolted back on (maybe a centimeter gap instead of being flush). I am suspecting this is the cause of my issues and not the NGK plugs. How to you get that wire tract off so it's out of the way and I can get the coil back on properly and do further testing?

 

That wire track can be moved just enough to facilitate the removal and installation. Just did the plugs and was able to move it. Good luck

 

Reseat your C.O.P also oem plug is all I use to avoid tantrums with H3's.

 

if i learned one thing here its use gm oem plugs!!
at autozone they were $7x5=35 with a $2 rebate per plug that i never got.

but the h3 runs perfect, no messing around on plugs.

 

Proper gap on the plugs?

 

Going to reseat the C.O.P. on the first cylinder, where I was having an issue with the wire tract.

These were pre-gapped NGK plugs and I verified that they are gapped to .40.

So what really are the OE plugs? Partsgeek is telling me Iridiums?
http://www.partsgeek.com/catalog/200...park_plug.html

 

I would NEVER use rice plugs.

AC Delcos are available anywhere and that is what the I5s use all the way out to 100K miles. Put in something else and you are just asking for trouble.

 

Work great on my supercharged AMG! Okay I get it... I5 started up like a lawnmower, so even if one coil pack was not seated properly it was very rough. I'll try the AC Delco plugs I can buy locally.

 

Picked up some AC Delco iridiums versus the NGK's on my lunch break. See where these get me...

 

I run several GM vehicles, and all I use are ACDelco plugs