Spark Plugs

[Crazy Paul]

Stock.

GM Performance Parts L92 Spark Plug, 41-985

#12571164
AC Delco 41-985

This is a spark plug for the new 2007 Aluminum Block and Aluminum
Head L92 engine. It is not recommended changing the gap from
.040".

[Andy@Livernois]

so same .708 reach tapered seat... but now they are factory iridium?

[GRRRR8]

That is correct. They are made by NGK too. It just says Delco.

[Crazy Paul]

Information on New Spark Plugs and Gapping #03-06-04-060 - (10/24/2003)

A new spark plug has been released for use in the above vehicles. The new spark plug has an Iridium tip instead of the current Platinum tip. Due to the different tip design, the gap of the spark plug has also changed. The new spark plug, P/N 12571164 with AC Delco P/N 41-985, is gapped to 1.01mm (0.040 inches) when the spark plug is made. The spark plug gap is set during manufacturing and should not be changed or damage to the spark plug may result. Any new spark plug found to not be properly gapped should not be used.



[Word is they are re-badged NGK Iridiums]

Service Intervals I've checked for cars fitted with these say "change at 100k miles"........don't think I'd leave them that long personally.

[GTPprix]

They are NGK plugs just tagged AC-D. NGK is moving back to being the majority supplier to GM for plugs and possibly NTK for O2 sensors.

[GRRRR8]

I fixed that! I am looking at the plug, reading NGK on nut and typing Nippon! IDIOT!!!

[Crazy Paul]

Info I have says first spark plug change on these at 100k miles.

Anybody got different info ?

[wreckwriter]

Do these plugs, the AC Delcos, require a metric plug wrench? If so, what size please?

[GRRRR8]

Thats correct, but I have found ck them at 50-60k and regap. When I did my headers I checked all plug gaps and not 1 was .040!

[GTPprix]

Info I have says first spark plug change on these at 100k miles.

Anybody got different info ?

Thats typical GM stuff for Iridium plugs now... you can if you want to ;) I wouldnt let any plug go that long but thats just me.


Do these plugs, the AC Delcos, require a metric plug wrench? If so, what size please?

Nope standard (thank God!)


I fixed that! I am looking at the plug, reading NGK on nut and typing Nippon! IDIOT!!!

Charlie is having a Chris day :D

[GRRRR8]

Thats typical GM stuff for Iridium plugs now... you can if you want to ;) I wouldnt let any plug go that long but thats just me.



Nope standard (thank God!)



Charlie is having a Chris day :D

LMAO!! I cant believe when that happens! I am thinking 1 thing, knowing its wrong, verify the correct info and type in the wrong info. WTF!

[Crazy Paul]

Thats typical GM stuff for Iridium plugs now... you can if you want to ;) I wouldnt let any plug go that long but thats just me.

Me 3

[wreckwriter]

Has any actually changed plugs on a G8 yet? The rear plug on the passenger side looks like its going to be a major bitch.

[GRRRR8]

That is the hardest 1, but the others are so easy and the plug wires are a breeze, that I guess it is a small trade off.

[wreckwriter]

That is the hardest 1, but the others are so easy and the plug wires are a breeze, that I guess it is a small trade off.

OK, one more probably dumb question. What's the deal with the little metal sleeves around the plugs? Do those come off or does the socket fit inside to get the plug in/out? I've not seen such things before.

[GRRRR8]

The sleeve is on the boot itself. It acts as an extra heat shield.

[wreckwriter]

The sleeve is on the boot itself. It acts as an extra heat shield.

It is??? Duh.... OK, thanks. Sure looks like the boot goes inside of it. Interesting.

[Crazy Paul]

OK, one more probably dumb question. What's the deal with the little metal sleeves around the plugs? Do those come off or does the socket fit inside to get the plug in/out? I've not seen such things before.

LOL WUT ?

You mean the ones attached to the plug wires ?

http://i2.photobucket.com/albums/y20/PerthPurplePenguin/car%20parts/P2020130.jpg

[GRRRR8]

They started that a few years back. If I am not mistaken, I think the 3800
V-6s were the first to have that heat shield.

[wreckwriter]

Never saw such a thing in my life. Guess I'm just a dinosaur....

[GRRRR8]

You aren't still looking for the points are you? LMAO!

[wreckwriter]

You aren't still looking for the points are you? LMAO!

Heh, no, not even looking for the distributor any more :)

[GRRRR8]

LOL!!! That was my next question. I can remember when they started putting fuel pumps in the tank and people would go nuts with a flash light and a mirror seeing where it was on the block! Better yet when the 4.6 Ford came out with coil on plug, you couldnt see the plugs. I was told by a rookie tech " hey man, they want a tune up but this truck doesnt have plugs!" REALLY?!?!

[wreckwriter]

That pump in the tank thing is a pain. I once had an old Chrysler that burned one out. Was a major bitch...