H3 Spark Plug Change
 

I was just curious on how to get to and change the spark plugs on my 06 HUMMER H3 and also was curious if anyone has used the new E3 spark plugs and if so how do you like them and can you notice in performance and gas mileage change. I seen an article where they are suppose to give around a 8hp increase and around a 12 to 14 percent increase in gas mileage. Thanks for any help!

I've heard a couple bad things about e3's on the H3. I had them in for about 3,000 miles and swapped them out before I had any issues. Can't remember what forum it was on, but they caused a lot of problems for one guy that only had maybe 10,000 on them (could be more or less, I forget) but he went to the dealer a few times and spent a lot on diagnostics before finding out it was the plugs. Do a search on e3's and you'll find the exact details since I'm sure I missed something, but more than one of us have taken them out.

Hey Motley1987,
Just wanted to say Thank You for your response and advice and I will definitely do a lot more research before I do that. It is great to have a forum to go to and get some answers about the H3 only. I have only had mine for a short time and have done a lot of appearance upgrades but not a lot of performance ones yet and now I am getting to those and figure before I spend the money, ask people who have had there's for a while. I have the Adventure/Luxury Package and I absolutely love it. Anyway, Thanks For Your Help!

I don't think I've made any mods especially performance related without searching or asking here first, so you should be able to get a lot of opinions from people that have made any changes you're thinking of making. Good luck!

I would be shocked to see a 12-14% mpg increase by changing the plugs to a new type. Regardless of brand.

Spark plugs are rated for 100K miles on H3 but I would probably start looking at them at about 65K unless truck has issues. I would only use OEM because H3 uses Hei ignitions and most other plugs will not hold up, hence problems with the brand you mentioned.

2006 h3 79kmiles spark plus just got changed
 

I just did a spark plug change at 79,ooo miles... lemw tell you they were burnt to hell.. and now it cranks and idles sooo smooth gigantor noticable difference... did spark plugs 1-4 and doing 5 tomorrow as i need a 5" extention to fit underneeth the body on the furthest one.. also i did a huge boo boo... learn from my mistake.. i over torked the bolt that holds the solenoid to the motor, and snapped the bolt.. luckily i was able to get the half of the bolt out the block with needle nose pliers.. i am now going to napa tomorrow sence lowes didnt have a replacement. And gm only had it with the entire assembly ... its a m6 metric bolt. Not sure of leangth though, like 4" or 60mm ill check tomorrow. Other than that it was the biggest renewal, noticable renewal job i have done yet... now its like a new motor...

I used the acdelco iridium ones... they were pre gapped to specs around. 40 but i double checked to make sure.... and the factory ones i pulled out that were burnt to hell were all different any where from. 40-.50 , motor running like brand new...

I'm sold, Im going to do mine now

ACDelco is the only way to go on the H3.