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#1 timh975

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Posted 18 April 2006 - 03:49 PM

Hey guys, just replaced the original platinum tip plugs on my 6.0 liter with the iridium plugs. The new plugs are pregapped at .040", but the sticker under the hood says to gap the plugs at .060". The guy at the dealer said to leave the plugs at .040", it will run fine and will also run a little cooler. So for now I left them at .040", and it runs good. Should I take them back out and set them at .060", or leave them? If I leave it will that decrease gas mileage you think?
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#2 Bish

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Posted 18 April 2006 - 04:17 PM

Hey guys, just replaced the original platinum tip plugs on my 6.0 liter with the iridium plugs. The new plugs are pregapped at .040", but the sticker under the hood says to gap the plugs at .060". The guy at the dealer said to leave the plugs at .040", it will run fine and will also run a little cooler. So for now I left them at .040", and it runs good. Should I take them back out and set them at .060", or leave them? If I leave it will that decrease gas mileage you think?

<{POST_SNAPBACK}>


The iridiums ate .040 and everything else is .060.
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#3 rjirvine

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Posted 18 April 2006 - 04:31 PM

Hey guys, just replaced the original platinum tip plugs on my 6.0 liter with the iridium plugs. The new plugs are pregapped at .040", but the sticker under the hood says to gap the plugs at .060". The guy at the dealer said to leave the plugs at .040", it will run fine and will also run a little cooler. So for now I left them at .040", and it runs good. Should I take them back out and set them at .060", or leave them? If I leave it will that decrease gas mileage you think?

<{POST_SNAPBACK}>


The iridiums ate .040 and everything else is .060.

<{POST_SNAPBACK}>


I replaced my plugs at 93k from platinums to iridiums. You're correct, the gap went from .060 to .040. I checked them before I installed them just to make sure, and they were all correct. I didn't notice any difference, and it idles smooth.

#4 MS3DALE

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Posted 19 April 2006 - 09:13 AM

This should help,

Document ID# 1396703


--------------------------------------------------------------------------------


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



Models: 2004 Buick Ranier

2002-2004 Cadillac Escalade, Escalade EXT

2003-2004 Cadillac Escalade ESV

2004 Cadillac CTS-V

1997-2004 Chevrolet Corvette

1998-2002 Chevrolet Camaro

1999-2004 Chevrolet Silverado

2000-2004 Chevrolet Suburban, Tahoe

2002-2004 Chevrolet Avalanche

2003-2004 Chevrolet Express, TrailBlazer

1999-2004 GMC Sierra

2000-2004 GMC Yukon, Yukon XL

2001-2004 GMC Yukon Denali, Yukon XL Denali

2002-2004 GMC Sierra Denali

2003-2004 GMC Envoy XL

1998-2002 Pontiac Firebird

2004 Pontiac GTO

2003-2004 Hummer H2

with 4.8L, 5.3L, 5.7L or 6.0L V-8 Engine (VINs V, P, T, Z, G, S, N, U -- RPOs LR4, LM4, LM7, L59, LS1, LS6, LQ9, LQ4)




--------------------------------------------------------------------------------

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.



GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


Copyright General Motors Corporation. All Rights Reserved.


--------------------------------------------------------------------------------
Document ID# 1396703

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#5 timh975

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Posted 20 April 2006 - 06:14 PM

Hey all, thank you for the help.
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#6 daddy

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Posted 20 August 2009 - 10:09 PM

This should help,

Document ID# 1396703


--------------------------------------------------------------------------------


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



Models: 2004 Buick Ranier

2002-2004 Cadillac Escalade, Escalade EXT

2003-2004 Cadillac Escalade ESV

2004 Cadillac CTS-V

1997-2004 Chevrolet Corvette

1998-2002 Chevrolet Camaro

1999-2004 Chevrolet Silverado

2000-2004 Chevrolet Suburban, Tahoe

2002-2004 Chevrolet Avalanche

2003-2004 Chevrolet Express, TrailBlazer

1999-2004 GMC Sierra

2000-2004 GMC Yukon, Yukon XL

2001-2004 GMC Yukon Denali, Yukon XL Denali

2002-2004 GMC Sierra Denali

2003-2004 GMC Envoy XL

1998-2002 Pontiac Firebird

2004 Pontiac GTO

2003-2004 Hummer H2

with 4.8L, 5.3L, 5.7L or 6.0L V-8 Engine (VINs V, P, T, Z, G, S, N, U -- RPOs LR4, LM4, LM7, L59, LS1, LS6, LQ9, LQ4)




--------------------------------------------------------------------------------

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.



GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


Copyright General Motors Corporation. All Rights Reserved.


--------------------------------------------------------------------------------
Document ID# 1396703


I love you, Rich. :lol:

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#7 MS3DALE

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Posted 20 August 2009 - 10:21 PM

WTF! :lol:

Go pick on Jeff!! :) :P

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'07 SILVERADO Z71 LT2 "VortecMAX" 6-Liter,"Super-Duty" Auto Trans,9 1/2" rear-end w/3.73 G80 Locker,XM,On-Star,BOSE speaker system,Stabilitrak,Block Heater,Sunroof,18" ARE "Cannon" Wheels w/LT275/65R18 Goodyear Wrangler AT/S tires.
Custom tune by Justin at Black Bear,CORSA "Sport" exhaust system,EXTANG "Full-Tilt" snapless tonneau cover,Rough Country 1.5" front leveling kit,Fabtech 1" rear lift blocks,EZ-Down tailgate damper.
GM accessories...Hood Deflector,Molded Mud-Flaps,Ventvisors,Catch-All Floor-Mats,Bedrail Protectors,BedRug Bedliner & Bedmat,and a GM Performance Parts cold-air intake.

2011 CAMARO 2SS/RS - LS3/M6 - Inferno Orange Met. - HURST short-throw - Roto-Fab CAI - Kook's LTs - CORSA exhaust - Black Bear tuned (playtoy!)
2012 CRUZE 1LT - Blue Topaz Met. - RS pkg.- Convenience pkg. (work car!)

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#8 daddy

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Posted 20 August 2009 - 10:24 PM

WTF! :)

Go pick on Jeff!! :P :P


I was honestly wondering about this situation. I just put new 41-985's in the Tahoe last weekend and knew they were gapped at .040 but I also was looking through the manual last night and saw it calling for .060. Your post cleared everything up for me! Thanks! :lol:

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#9 MS3DALE

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Posted 20 August 2009 - 10:32 PM

OK,I was gonna' say.....man this thread is over 3 years old,WTF!

BTW...Headin' down towards your Dad's tomorrow morning,hope the weathers nice down there this weekend!

sig1alternate.png
'07 SILVERADO Z71 LT2 "VortecMAX" 6-Liter,"Super-Duty" Auto Trans,9 1/2" rear-end w/3.73 G80 Locker,XM,On-Star,BOSE speaker system,Stabilitrak,Block Heater,Sunroof,18" ARE "Cannon" Wheels w/LT275/65R18 Goodyear Wrangler AT/S tires.
Custom tune by Justin at Black Bear,CORSA "Sport" exhaust system,EXTANG "Full-Tilt" snapless tonneau cover,Rough Country 1.5" front leveling kit,Fabtech 1" rear lift blocks,EZ-Down tailgate damper.
GM accessories...Hood Deflector,Molded Mud-Flaps,Ventvisors,Catch-All Floor-Mats,Bedrail Protectors,BedRug Bedliner & Bedmat,and a GM Performance Parts cold-air intake.

2011 CAMARO 2SS/RS - LS3/M6 - Inferno Orange Met. - HURST short-throw - Roto-Fab CAI - Kook's LTs - CORSA exhaust - Black Bear tuned (playtoy!)
2012 CRUZE 1LT - Blue Topaz Met. - RS pkg.- Convenience pkg. (work car!)

My Garage


#10 MS3DALE

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Posted 20 August 2009 - 10:34 PM

Oh BTW....The bulletin above has been updated to cover up to the 09's as well now.

sig1alternate.png
'07 SILVERADO Z71 LT2 "VortecMAX" 6-Liter,"Super-Duty" Auto Trans,9 1/2" rear-end w/3.73 G80 Locker,XM,On-Star,BOSE speaker system,Stabilitrak,Block Heater,Sunroof,18" ARE "Cannon" Wheels w/LT275/65R18 Goodyear Wrangler AT/S tires.
Custom tune by Justin at Black Bear,CORSA "Sport" exhaust system,EXTANG "Full-Tilt" snapless tonneau cover,Rough Country 1.5" front leveling kit,Fabtech 1" rear lift blocks,EZ-Down tailgate damper.
GM accessories...Hood Deflector,Molded Mud-Flaps,Ventvisors,Catch-All Floor-Mats,Bedrail Protectors,BedRug Bedliner & Bedmat,and a GM Performance Parts cold-air intake.

2011 CAMARO 2SS/RS - LS3/M6 - Inferno Orange Met. - HURST short-throw - Roto-Fab CAI - Kook's LTs - CORSA exhaust - Black Bear tuned (playtoy!)
2012 CRUZE 1LT - Blue Topaz Met. - RS pkg.- Convenience pkg. (work car!)

My Garage


#11 daddy

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Posted 20 August 2009 - 10:38 PM

OK,I was gonna' say.....man this thread is over 3 years old,WTF!

BTW...Headin' down towards your Dad's tomorrow morning,hope the weathers nice down there this weekend!


You are a travelin' machine!

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#12 MS3DALE

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Posted 20 August 2009 - 10:42 PM

OK,I was gonna' say.....man this thread is over 3 years old,WTF!

BTW...Headin' down towards your Dad's tomorrow morning,hope the weathers nice down there this weekend!


You are a travelin' machine!


Yeah! Then I'm headin' back down next month for this.....Earnhardt car show
My buddies boss ask me if I'd help them out down there for it,Looks like a good time!
Oh...and I'll be back in Oct. for the NASCAR race too!! :lol:

Edited by MS3DALE, 20 August 2009 - 10:48 PM.

sig1alternate.png
'07 SILVERADO Z71 LT2 "VortecMAX" 6-Liter,"Super-Duty" Auto Trans,9 1/2" rear-end w/3.73 G80 Locker,XM,On-Star,BOSE speaker system,Stabilitrak,Block Heater,Sunroof,18" ARE "Cannon" Wheels w/LT275/65R18 Goodyear Wrangler AT/S tires.
Custom tune by Justin at Black Bear,CORSA "Sport" exhaust system,EXTANG "Full-Tilt" snapless tonneau cover,Rough Country 1.5" front leveling kit,Fabtech 1" rear lift blocks,EZ-Down tailgate damper.
GM accessories...Hood Deflector,Molded Mud-Flaps,Ventvisors,Catch-All Floor-Mats,Bedrail Protectors,BedRug Bedliner & Bedmat,and a GM Performance Parts cold-air intake.

2011 CAMARO 2SS/RS - LS3/M6 - Inferno Orange Met. - HURST short-throw - Roto-Fab CAI - Kook's LTs - CORSA exhaust - Black Bear tuned (playtoy!)
2012 CRUZE 1LT - Blue Topaz Met. - RS pkg.- Convenience pkg. (work car!)

My Garage


#13 2COR517

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Posted 21 August 2009 - 08:51 PM

Regardless of the type of plug (iridium, platinum, etc) the gap should be .040". It's just "convenient" it coincides with a new plug type.
Sharing my experience & opinions. Some I learned the hard way, some I learned from those I trust very much.

#14 daddy

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Posted 21 August 2009 - 09:15 PM

Regardless of the type of plug (iridium, platinum, etc) the gap should be .040". It's just "convenient" it coincides with a new plug type.


The manual calls for .060 and the TSB clearly states the Platinum plug uses the .060. Why is it you say it doesn't matter?

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#15 2COR517

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Posted 22 August 2009 - 08:47 AM

The document Rich posted does not say to gap platinum plugs at .060".

GM had a drive-ability problem caused by the big gaps with the Vortecs in 96. Sloppy idle, pinging, etc. The solution was to tighten the gaps down. The large gaps put a tremendous load on the entire ignition system. They issued a document some time ago to tighten the gaps down to .040", long before iridium plugs came out. I don't have the actual document, but a friend of mine who is very much in the know shared this info with me. Apparently this info was distributed through GMs "Techline", not a formal TSB. Which is why it doesn't show up on AllData. If you recall, GM tried big gaps in the seventies, it didn't work then either.

The coating, whether it's copper, platinum, iridium, doesn't change the physics of sparking that gap under the extreme pressure of the combustion chamber.

You can run whatever gap you like, I have mine at .040. I will tell you from first hand experience that when I had the Bosch+4 in my truck, with their huge gaps, I thought my motor was toast. Sloppy idle, overheating, no power, non stop pinging. I put in the AC Delcos gapped at .040 and it felt like a brand new truck. I only changed the plugs and had that difference.
Sharing my experience & opinions. Some I learned the hard way, some I learned from those I trust very much.




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