E3 Spark Plugs On An 8.1l

Hulk1999 · March 23, 2009

So i decided to continue my 100K mile maintenance on the truck today. I've already done fliuds (except the Trans). Got to the Plugs and wires today. I brought thundervolt 50 10.4mm and E3 spark plugs. The wires are beast by the way. The install with off with no problems. As soon as i started the truck up and was shaking hard . I read in another forum that the E3's would do that so i didn't think much of it. I drove about a hundred feet and the service engine light started to flash. Immeditaetly i'm thinking miss fire, i didn't get a good connection on one of the wires. checked everything and everything was good and tight. I didn't have any loss of power, the truck drove the same except it vibrated at idle and the light kept flashing. I took the truck over to a buddy who was tuning it for me and we did some data logging. He said that the knock was through the roof and was sure it was the spark plugs. I went ahead and got some OEM AC Delco Plats and installed them. Problem solved. Almost $100 bucks gone but the truck is running smooth. Oh yeah when i pulled the plug out of cylinder three and was black, smelled like gas, and the porcelin had seperated from the socket face. The old plugs were covered in ash and corroded really bad. My buddy who knows a thing or two about GM engines couldn't figure out how my truck was about to get a spark in the first place.

Moral of the story, the Big Block does not like E3 spark plugs .

Hulk

05on20s · March 23, 2009

Yea man, those E3 plugs are no good for domestic and imports. Glad you got it fixed.

txab · March 23, 2009

Best to stick with what it came with.

Kodiak450 · March 26, 2009

I experienced shake at idle with those E-3 plugs and decided to take them out and stick with AC delco as well. Problem solved after taking the E3 plugs out. I heard that the design of the plug could pose a hazard to the engine if one of the metal endings got hot and broke off. I did however at first after putting in the E3 plugs like the truck had a little more pep to it, but it didn't take long before I felt a vibration at idle and that got me concerned. I did read good reviews about people using them in lawn mower engines, unfortunately those plugs won't fit any of my small engines.

svensk · March 26, 2009

E3's been running fine in my 5.3. I have a tune so maybe it's somehow a better combo.

alaska511 · March 26, 2009

I tried a few different plugs in my 8.1.

I played musical plugs in many combinations with tune, CAI, exhaust, etc...nothing worked as good as the original AC Delco part # plugs

pennzoil29 · March 26, 2009

I have never used anything but AC-Delco spark plugs in a GM engine.

pm26 · March 28, 2009

OEM plugs often work the best. I was cautioned never to use Bosch plugs in my Mazda, so I use the OEM Denso plugs, engine still idles glass smooth with 226k miles on the clock. Of course, I replace the plug wires periodically too.