Iridium Plugs for GM 5.3

[Rhymingmechanic]

Has anyone used either the AC Delco 41-985 or NGK 7164, both iridium, in the 5.3 or similar truck engines? And if so, was there any noticeable difference between either plug and stock?

The stock plug is a platinum NGK 7862, but GM's recommended replacement is the AC iridium. However, the manual and underhood decal spec a .060 gap. The AC plugs are set at .040, with instructions to not re-gap. The NGK's are factory gapped at .060.

Could the new gap recommendation from GM mean that .060 was not optimum for the engine, or would it just be something about the replacement plug's design? If the smaller gap would help this pig's hot-weather ping, I'll use the AC's. I just want to make the right choice the first time, because the plugs are$6-$8 each, and the stock platinums are over $12. I have been using Fuel Power since fall, so maybe that will help the ping when the weather warms up.

Thanks for any input.

 

[BlazerLT]

Aren't the factory replacements the AC Delco plat?

 

[99 GASE2]

NGK makes the AC Delco Iridium spark plugs for GM.

Not sure about your gapping situation.

When I went from my stock original AC Delco Platinum spark plugs to NGK Iridium IX spark plugs: the gapping remained the same on my 3400-series V6 engine.

Some newer GM vehicles now come with Iridium spark plugs from the factory stock.

 

[Rhymingmechanic]

The truck is a 2001. The owner's manual lists numbers for Delco, NGK, and Denso platinum plugs, but the dealership parts department and an independent shop both say the new replacement is the Delco iridium, with the smaller gap.

 

[TheTanSedan]

Folks often complain about the cost of Iridium plugs . . . which I can understand at $12/ea.

I felt no problem in using DENSO Iridium (IK-16[?])in a new-to-me 2001 DODGE Ram V8-318 recently. Vehicle has about 95k on it. I ran FUEL POWER (and LUBE CONTROL) to start the internal clean-up process (over 8k), ending with aerosol throttle body & combustion chamber cleaner, then a 2-3 oz per cylinder overnight LC soak.

(Truck is now about finished with "wash" phase of A-Rx treatment, using DELO 10W-30 and BALDWIN B2-HPG).

The old plugs (stock Champions, likely second set judging by wear) were as clean as a whistle (something I've come to expect with FP) except on cylinders 6 & 8 where a common intake manifold gasket failure showed itself.

My health is failing and I was more than happy to buy plugs (and MAGNECOR wires) that would keep me from having to deal with this problem again for 60k or more OR to have to pay someone else to do it for me.

I find that few plugs look all that great past 30k, but that Iridium plugs are a nice exception.
I recently changed the ones in my folks 2001 OLDS Intrigue (about 85k on them, 100k change interval recommended) and was pleased, overall, with their condition.

The use of FP-60 (and fixing the manifold problem and any others ASAP) will keep the combustion chambers/piston crowns cleaned up, and the right oil/filter combination -- via analysis -- will ensure reduced, minimal wear.

I feel, then, that even a vehicle I essentially knew nothing about (outside of a clean CARFAX) will allow me to keep it running as close to new as possible, for the longest period of time justifies having to spend $105.00 on spark plugs.

I wouldn't in the least hesitate to follow the GM guidelines if this is their recommendation, and to purchase the best possible Iridium plug.

I'd also ask this question on one of the better boards for GM truck owners, do some WWW searching as well for opinions.

Also, www.sparkplugs.com/

(See all links, FAQs, etc)

[ March 27, 2005, 01:17 AM: Message edited by: TheTanSedan ]

 

[Bugshu]

Live long and prosper friend !!!!

Happy Motoring to You,

Bugshu