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Spark Plug Electrode Question

Annihilator

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Annihilator Enthusiast

Annihilator

Posted
Posted

Hi guys, I'm about to install some Delco 41-952's in my '00 Z71 and I noticed that some of the electrodes don't line up perfectly. Some of the ground electrodes are bent a tad to the left or right or they are a tad passed the centre electrode. Is this is big deal? Or should I bend them so they are perfectly line up on top of each other?

ChRoNo16 Enthusiast

ChRoNo16

Posted
Posted

They should be perfectly on top.. Take them back to where you bought them and get new ones? seems to me you got a bad batch or something. Idk mine are always straight on. make sure you gap them right too.

txab Senior Enthusiast

txab

Posted
Posted

I pretty sure GM is now recommending the plug gap be .040 instead of .060, which means you'd need a different set of plugs. 41-952 is the older plug #. Don't re-gap the plugs you have. Sounds like the plugs you have may have been bounced around a bit and the electrode may not be gapped properly anymore, check before installing. The ground electrode should be centered, not off to one side or the other

 

41-110 is the new recommended plug. It is Iridium

dlstewart01 Senior Enthusiast

dlstewart01

Posted
Posted

Here is the TSB changing the spark plug part # and the gap to .040. The 41-985 has been superseded by 41-110.

 

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

Annihilator Enthusiast

Annihilator

Posted
  • Author
Posted

Thanks guys. Yea, I knew that the new recommended plugs were iridium but I wanted to stay with what the car came with. I also have had no problems with platinums lasting 100k miles. I'm gonna go ahead and return em as they are obviously messed up.

Annihilator Enthusiast

Annihilator

Posted
  • Author
Posted

Why is that? The original plugs were platinum and my emissions label states .060. Now I checked NGK's site and their newest G power single platinums are to be gapped at .040. Since they are both single platinums I would think they should be gapped the same? No?

 

You can stay with platinums, but still need to get plugs that are gapped to .040
EZDAAR Enthusiast

EZDAAR

Posted
Posted
Why is that? The original plugs were platinum and my emissions label states .060. Now I checked NGK's site and their newest G power single platinums are to be gapped at .040. Since they are both single platinums I would think they should be gapped the same? No?

 

You can stay with platinums, but still need to get plugs that are gapped to .040

 

 

 

.60 gap causes random missfire. use .40.

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