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.

Stick with the OEM plugs, too many have tried some "new fangled" plugs and they have had nothing but problems.

Well that bolt that i snapped, the first one you remove, holds the solenoid assembly down on top of spark plug... its a 6mm 100pitch 3 3/4" bolt, that not gm carriers nor local aoto parts stores, not napa, not lowes, nobody... i had to get the machine shop i work for to re create this bolt for me... so when YOur tightening it back down, as soon as it stops THREDING IN, DONT TIGHTEN IT, DONT WANT TO SNAP IT OFF LIKE ME.. LOL..

6MM 1.0 pitch = standard thread. PN 11519038 $4.00 on line.

The coil pack bolt TQ should be minimal, like 10-11 lb ft, one hand snug kinda thing.

did you guys ue the AC Delco Iridium plugs?

Just did plug change, took less than 1 hour. I have 100k on originals and they were shot. The gap was huge. Did not help with RPM dropping at stops, however they did need changing.

I used the ac delco iridium plugs to replace my plugs this weekend . No problems so far in the first 150 miles or so. I thought they were the oem plugs as per napa. I also read a couple threads in which other people used the iridium without issues. unless Im mistaken?

on another note....the owner's manual says gap at .042"....the repair manual says .044-.050......and the plugs said .043! i gapped mine at close to .043.

Mine were pre gapped at .041 and left em that way because the old ones were so big

same as bigdog100
 

Mine were pre gapd at. 41 and i left them that way cause after awhile the gap increases obviously looking at my stock 79,000 mile ones that were from. 45-.50 gap

Yes i used acdelco IRIDIUM ones... they are 110% perfect... if anyone els has problems with these, i bet its not the plug and more user error during the change, maybe plug not screwed in good, gap off, solenoid not booted on good, or not lubricated with the dielectric grease, or could be alot of things, but, im just an average, pre owned 2006 h3, changed my self not knowing anymore than i read here... acdelco iridium, great ride and idle...

i just changed the plugs on my '06 at 74k. 1st cylinder's a bear but otherwise a pretty easy plug change. smoothed out the idle, better acceleration and pulls stronger in the higher rpm's. be careful gapping iridium plugs. i checked mine out of the box - they were all at .041 and i left them. the ones i pulled out were gapped between .037 - .046 :eek:


here's a form for a $2 per plug rebate on ac delco iridium plugs. it's good for purchases until 6/30/12.

http://www.acdelco.com/pdf/18-TP_H443020_SparkPlug.pdf


:)

oem only for the h3

yes, delco iridiums are oem.

H3 Spark Plug Replacement
 

I was replacing my spark plugs AC Delco iredium, on 06 H3. I did cylinder # 2 first-just easy access, then went to cylinder # 3, removed spark plug, no problem but putting the new one in it felt tight so I backed it out and tried again but still felt the same.. So I proceeded on to cylinders # 1, # 4, and # 5, all smooth and easy. I'm back on # 3 but not sure what to do, can thread it maybe 1/4-1/3rd in and then it's really tight. Any suggestions?
athlexce
New User


Posts: 1
Joined: Sun Sep 23, 2012 8:37 am
Vehicle: 06 H3
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Tight park Plug Threads
 

If anyone has this problem, I used a 14mm extended spark plug thread chaser and it fix he problem...FYI:)

Thanks for the tip.
Chris

Torque on the Plugs?
 

Just getting ready to change the plugs on my 2006 H3 and was wondering if anyone knows the proper torque? I looked up the torque specification for a 2007 PT Cruiser (Just happened to have that Hayes manual at hand) and they call for 156 inch pounds - sounds about right for an aluminum head.

Any suggestions?

Thanks!

Another Question - Wire Loom on Top of Spark Plug by Radiator
 

So I was able to change 4 of the 5 plugs (went with AC Delco Iridium plugs). The fifth one is the one closet to the radiator. There is a plastic tray or "wire loom" that sits over the coil pack and there doesn't seem to be enough room to get the coil pack out without moving the wire loom.

There are two plastic fasteners inside the loom (again its more like a plastic tray). The fasteners are white in color and look like 3/4s of a circle. The spin around, but spinning them doesn't seem to loosen them, or put them in a position where the loom can be lifted slightly. That's all it needs to do is to be lifted slightly.

Any suggestions?

Thanks.

BTW, I figured out the torque for the plugs - I went with 12 foot pounds, if I did it again, I'd probably go with 14 because 12 foot pounds doesn't seem that tight.

guys after reading this thread I am changing this weekend...BUT looking at these for 89K miles any opinions?

Thank you in advance.

Changed mine at about 75k miles because I thought it was about time. Runs the same.

I tell you what.. The dealer replaced my head, sensor and plugs and I did not notice any gas mileage improvement whatsoever. Down the road I might pull them to make sure they are gaped right.

Since you guys insist upon keeping this 2009 thread alive, let me sum it up for you:

1) Spark plug change for all H3s is 100,000 Miles, change them before that and you are just pissin away $$;
2) Use OEM ACDelco plugs; and,
3) Aftermarket super duper special spark plugs (insert brand name x here) are not going to create any performance increase in a high capacity discharge computer controlled distributorless ignition. Spark timing, length and intensity are all computer controlled. The GM systems put out tons of Juice and the ACDelcos are engineered to take it. The plug itself is simply the conduit, today a good one is measured by its ability to reliably withstand long service, it can ONLY do what the computer tells it.

I run Delco irridiums in all my GM vehicles. Excellent plug.imho

I replaced mine at the 100k mark with AC Delco OEM's. The originals still looked remarkably good though, I probably could have even just regapped them for another 100k of use!

How did u get the front plug out , with it being under the wiring harness. Was able to change the other ones with no problem.

LOOK CLOSE , you can move the harness,
i "wasted" mon ey and did mine at 60000, nervous about long thread plugs in aluminium because of previous old car galling and threading problems. i had no trouble with the h3 plugs, saved the old ones!! ill put them back when im older and grayer.
i added a tiny amount of anti seize on new ones

Spark Plugs?
 

I have an 07 H3, does anyone know if I get a basic tune-up/change spark plugs if that will improve my fuel efficiency. Shop was talking about replacing a throttle body sensor that will run 900 dollars.

This thread is pretty old to tack on another question.

How many miles on your truck?

Get away from that shop quickly. The Throttle Body (TB) sensor is built into the TB, the sensor itself would not be changed, they would simply be replacing your TB. A brand new AC Delco TB is $230 or less, 4 bolts hold it in place, all that has to be done to replace it is to remove the intake, unplug the electrical harness, unplug the EVAP hose, remove 4 bolts, and swap it in. While the intake is off, all 5 spark plugs are directly on top of the engine with nothing in the way, one bolt hold the coil on each plug. The AC Delco plugs are like $3/ea. Book time to do both is less that 1 hour, but let's just say 1 full hour, even 2. Is their hourly rate $655 (Parts $245 - $900 quote = $655), or $327.50 if it takes them 2?

TB with couple coil packs below covering the spark plugs.
Attachment 11042

There is no "tune up" per se for an H3, they use a distributorless ignition with coil on plug packs. Spark plugs will easily go 100K miles before needing replacement. So unless your truck is running like crap from spark plugs that have gone past their life cycle (over 100K), changing plugs won't do much of anything for fuel economy.

If you have never cleaned your TB and MAF sensor, that is your "tune up". There are threads here on how to do it, forget that shop, do it yourself, including spark plugs if you want.

I am having a problem with the RPM dropping at stops. did you ever figure it out

Figure what out?

Search "false stall" here at HF. Read away, but the short list is in the FAQ section here. Acts like it wants to stall/rough idle -No CEL -What To Do: