Ac Delco Iridium Plugs

[scott0303]

Guys, I need some help. I am going to change my plugs on a 99 Sierra 5.3l With an employee discount, I was able to buy some AC Delco iridium plugs at a pretty good price. Guy at NAPA told me I need to set the gap on them at .040 The first couple plugs I checked werent set at that. Before doing anything, I read a few other things online that said you should never regap an iridium plug, that it should be set correctly from the factory if its the right plug for your truck. After checking a few more plugs, none of the gaps are the same so I dont see how that is possible. I dont see why they couldnt be regapped but what do I know?. Need some thoughts

[DaveH71]

I wouldn't gap the iridiums if i were you, they should be good to go outta the box. They reason why your old plugs are all different gaps is because the electrodes have worn down after awile, im assuming you old plugs were copper or platinums?

[scott0303]

I wouldn't gap the iridiums if i were you, they should be good to go outta the box. They reason why your old plugs are all different gaps is because the electrodes have worn down after awile, im assuming you old plugs were copper or platinums?

 

 

No the new plugs have different gaps. They are all not the same. A couple are one gap, another couple another gap. definitely not the same throughout the new set of 8.

[DaveH71]

oh i see, i misunderstood you post. Yes though all the new iridium plugs should be gapped at .040, thats the standard for the iridium. The old coppers were .060

[dlstewart01]

Service Information 2000 Chevrolet Chevy K Silverado - 4WD | Sierra, Silverado, Suburban, Tahoe, Yukon (VIN C/K) Service Manual | Document ID: 1903277

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#03-06-04-060A: Information on New Spark Plugs and Gapping - (Feb 12, 2007)

 

 

Subject: Information on New Spark Plugs and Gapping

 

 

Models: 2004 Buick Rainier

 

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)

 

 

 

Attention: Please disregard the Set Gap Per Vehicle Specification statement on the side of an ACDelco® Iridium Spark Plug Box. The statement will be removed from the boxes in the future.

 

 

 

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

 

This bulletin is being revised to bring attention to the Set Gap Per Vehicle Specification on the ACDelco® Iridium Spark Plug Boxes. Please discard Corporate Bulletin Number 03-06-04-060 (Section 06 -- Engine/Propulsion System).

 

 

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

 

• 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 1.01 mm (0.040 in) when the spark plug is made.

 

 

Notice: 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

 

 

© 2008 General Motors Corporation. All rights reserved

[scott0303]

Service Information 2000 Chevrolet Chevy K Silverado - 4WD | Sierra, Silverado, Suburban, Tahoe, Yukon (VIN C/K) Service Manual | Document ID: 1903277

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

 

#03-06-04-060A: Information on New Spark Plugs and Gapping - (Feb 12, 2007)

 

 

Subject: Information on New Spark Plugs and Gapping

 

 

Models: 2004 Buick Rainier

 

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)

 

 

 

Attention: Please disregard the Set Gap Per Vehicle Specification statement on the side of an ACDelco® Iridium Spark Plug Box. The statement will be removed from the boxes in the future.

 

 

 

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

 

This bulletin is being revised to bring attention to the Set Gap Per Vehicle Specification on the ACDelco® Iridium Spark Plug Boxes. Please discard Corporate Bulletin Number 03-06-04-060 (Section 06 -- Engine/Propulsion System).

 

 

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

 

• 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 1.01 mm (0.040 in) when the spark plug is made.

 

 

Notice: 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

 

 

© 2008 General Motors Corporation. All rights reserved

 

 

perhaps I received an old box because the box of iridiums I just bought have gap sizes that are not the same. They are not .040. Some smaller and some bigger. Something tells me that I shouldnt be installing them that way. I guess what I am trying to say is that they were not set at the factory with all these different gaps in a box of 8

[txab]

Take 'em back and get another box. Take your feeler gauge and check them while you are at the store

[scott0303]

Take 'em back and get another box. Take your feeler gauge and check them while you are at the store

 

 

took them back and showed them the varying gaps. they still insisted I gap them myself. I just asked for my money back and went to Oreilly's

[scott0303]

having one heck of a time getting the back passenger side plug out. hate that the plugs are angled toward the back of the engine. Anyone have any suggestions on easier access to that back plug? Specialty tool? This is a 5.3l

[txab]

So your Oreilly's plugs are all set at the proper gap?

[dlstewart01]

That plug is no harder than the other ones. Put the socket on the plug, then put a short extension on the socket then put the ratchet on the extension. I believe I used a 3/8 drive the last time I changed plugs.

 

Took me no longer to get the back one out than any of the others. And I'm an old geezer.

 

Now the last time I changed plugs in the wife's V6 Buick I though they were going to kick my butt. Even after taking the front motor mount loose and rotating the engine, I could only get one hand on the back three plugs. But one must endeavor to persevere. Yeah I won that battle.

[Sly]

having one heck of a time getting the back passenger side plug out. hate that the plugs are angled toward the back of the engine. Anyone have any suggestions on easier access to that back plug? Specialty tool? This is a 5.3l

 

I have the spark plug socket with the universal swivel on it. Works like a charm. Sears carries them.