ACDelco Iridium Spark Plugs
08-27-2006, 12:43 PM
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ACDelco Iridium Spark Plugs Im changing the plugs on my car and i need to know what to gap them at. The ony thing i have done to my car is the K&N air filter and i have some headers that i bought but havent put them on and also i have a SLP Lid on the way. Sould i gap the plugs at .60 or .55?
08-27-2006, 03:27 PM
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Originally Posted by GMTECH4
you don't gap those plugs you will miss up the iridium tip look how thin it is
I just did my wifes Trailblazer. They're suppose to be at .043. Not one of the new plugs were the same. They varied from .038 to .055. These were ac delco 41-965 platinum's.
08-27-2006, 05:15 PM
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Originally Posted by GMTECH4
you don't gap those plugs you will miss up the iridium tip look how thin it is
and no where on the box it says pergapped.
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08-27-2006, 10:59 PM
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It's your money and your car i work at a gm-dealer and there is a technical service bulltin #03-06-04-060. this only applys to the iridium plugs not platinum.
08-28-2006, 12:05 AM
#9
my denso iridiums came pre-gapped, my tech said don't gap them.. even had a nice plastic ring around the electrode side to prevent damage and gap changes. I just put them in, no problems.
here's the link from their site:
http://densoiridium.com/installationguide.php
here's the link from their site:
http://densoiridium.com/installationguide.php
08-28-2006, 12:02 PM
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Originally Posted by GMTECH4
It's your money and your car i work at a gm-dealer and there is a technical service bulltin #03-06-04-060. this only applys to the iridium plugs not platinum.
Asmodeus, It doesn't say not to gap them. What that says it what I already said. If you don't know how to gap a plug imo you shouldn't be changing them. So at the very least they should be checked.
Installation Guide
IRIDIUM POWER™ GAPPING TIPS
Before attempting to gap any DENSO Iridium Power spark plug, please review the specification chart in the front of this catalog to verify the factory-preset gap. In most cases your Iridium Power plugs do not need to be gapped. Even with small variations in the factory set gap the ultra-efficient firing power design will compensate for those small variations.
""""""Should you decide to re-gap your Iridium Power plug, use extreme caution as improper gapping may damage or destroy the Iridium center electrode or porcelain center.""""""
To increase the gap size:
• Step 1: Use needle nose pliers or spark plug gapping tool to bend the ground strap up to the desired height. DO NOT LET THE PLIERS OR GAPPING TOOL TOUCH THE IRIDIUM CENTER ELECTRODE OR PORCELAIN.
• Step 2: Re-check the gap with a calibrated gapping tool.
To decrease the gap size:
• Step 1: Use the same method as above, however bend the ground strap down to the desired height. DO NOT LET THE PLIERS OR GAPPING TOOL TOUCH THE IRIDIUM CENTER ELECTRODE OR PORCELAIN.
• Step 2: Re-check the gap with a calibrated gapping tool. WARNING: Failure to follow these directions may permanently damage the spark plug. Note: Never use a round gapping tool to check the gap or to increase or decrease the gap setting.
WARNING: Failure to follow these directions may permanently damage the spark plug. Note: Never use a round gapping tool to check the gap or to increase or decrease the gap setting.
08-28-2006, 04:10 PM
#11
Originally Posted by WhiteRhino
Do they at least check the gaps. More than likely they just throw them in. This is the reason I never take my car to a dealer. No offense, it just bothers me when someone says I work at a dealer. Some of the dumbest mechanics I know work at dealerships.
Asmodeus, It doesn't say not to gap them. What that says it what I already said. If you don't know how to gap a plug imo you shouldn't be changing them. So at the very least they should be checked.
Asmodeus, It doesn't say not to gap them. What that says it what I already said. If you don't know how to gap a plug imo you shouldn't be changing them. So at the very least they should be checked.
08-28-2006, 04:15 PM
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simple..just check the gap.... .55-.60 is fine..they do come pre-gapped..checked mine and they were all .55/.57.....good enough unless you are racing or ****............. 
08-28-2006, 08:52 PM
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Originally Posted by Asmodeus
I never said Denso says don't gap them. Reread my post. Or, I got an idea. How about this. I won't change my plugs until I "learn how to gap them" if you don't post anymore until you learn some reading comprehension, ok?
Your exact words were; "my denso iridiums came pre-gapped, my tech said don't gap them". You took me saying "you" as if I was refering to "you" when it was a generalised statement. Refering to anyone that isn't sure how to gap a plug. Get over it, I wasn't singling or trying to bash you. 
So maybe you should learn how to comprehend as well. Untill then lighten up.
If you need you can send your plugs to me and I'll check/gap them for you. Bottom line, like Nhraman said as well. The gap should be at least checked. Being off a couple thousandths doesn't make a difference.
Last edited by WhiteRhino; 08-28-2006 at 09:04 PM.
08-29-2006, 11:40 AM
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What P/N Iridiums are you guys using? I looked up the OE plugs (I work at a GM dealer too) and it gave me 41-985 iridium. On the description it says "(DO NOT CHANGE SPARK PLUG GAP FROM .040")(ACDelco #41-985)(IRIDIUM)" and refers to a service bulletin. I checked the gap last night and they are all .038"-.040". Do I need to spread them to .055" or are these not the right plugs to use?
08-29-2006, 12:00 PM
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My car seemed to run rough when I left them at .040. I pulled them out and put them to .055. I'm not saying you should do it as well. Try them at .040. If all is fine then don't worry. My car is far from stock and I've had to move the gap for different style plugs. You would think .040 would be better for spark, but my car likes a wider gap for some reason. The reason it says not to deviate is probably because people mess up the iridium not doing it properly. I bought mine a long time ago and I remember it saying something to the effect to rec. app. gap. You can also find a different plug part number, same style plug with a gap closer to what you want. As long as it's for an Lsx application.
08-29-2006, 12:07 PM
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Ok. This is my first LS1 and if the plugs are as much of a PITA to change as my 5.3L truck's then I'd like to get it right the first time!
The car is mostly stock right now, just a lid and cat-back (LTs and ORY coming soon) but it has 82K mi. and I'm sure they've never been changed.
The car is mostly stock right now, just a lid and cat-back (LTs and ORY coming soon) but it has 82K mi. and I'm sure they've never been changed.
