I have been looking to replacing the Spark Plugs in my 2000 C 5 with Iridium Plugs. The manual states the gap is .060 " but in the Rock Auto listings they all appear to be pre set at .040"
and not to re gap. it appears the only one listed at .060" is the Champion Iridium. I am confused, what gap do I use? Thanks in advance, I could not find anything in the Search section of the Forum.

 

Platinum plug from the factory was .060 along the way there was a service bulletin about a change in plug design Iridium tip and new design gap is .040

 

Hope this TSB helps !!...whatever issues you have you should ALWAYS check TSB's if you can !!





#03-06-04-060B: Information on New Spark Plugs

and Gapping - (Jul 30, 2008)

This bulletin is being revised to add the Chevrolet SSR and the 2005 Pontiac GTO.

Please discard Corporate Bulletin Number 03-06-04-060A (Section 06 --

Engine/Propulsion System).

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, SSR, 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

2004-2005 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.

• 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.

 

Thanks. How would I check for TSB’s

 

If you go to this link and then go to knowledgebase and then to Tech Center...you should find TSB's there !!...if you don't have the factory service manual (FSM) you should pick a copy up !!..our cars are getting older and I'm certain some issues will pop up...I also use Mitchell which has a 3 year sub and is not to expensive and together with the FSM you can find just about anything !!


http://corvetteactioncenter.com/

 

Ac delco
41-110 if you can find them
otherwise 41-162 is the newest plug recommended by gm. The gm part number for 41-110 was discontinued.