Spark plugs wearing fast

[mbaker]

06 Buick 3800, new NGK platinum plugs ~20k miles factory gapped at .060 when installed. OVer the past week or 2 I have noticed what felt like a miss under light load but never turned on the light. Yesterday it did it again and did set a pending code for misfire on #1. Pulled that plug and the gap has opened to at least .080, otherwise the plug looks good. Since its easy to change all of these I am replacing them and see if that takes care of it, but am a little stumped why these plugs wore so quickly. With 130k at the time I expected these would be the last plugs I put in and havent had trouble with NGK in the past.

Any thoughts?

 

[Leo99]

Where did you buy the plugs? Lots of counterfeit ones around.

 

[JavierH19]

Where did you buy the plugs? Lots of counterfeit ones around.

This. I always buy plugs at chain stores. Just a couple bucks more but they're guaranteed to be real. Tons of them sold online on like amazon, ebay, and others are fakes.

 

[D60]

Yeah, counterfeit was also my concern. Guys with counterfeit Motorcraft plugs have seen rapid wear. NGKs are probably the most faked, at least according to the internet.

 

[KrisZ]

If you bought them on Amazon, they are probably fake.

 

[mbaker]

I got them from Rock Auto when I ordered some other parts. I replaced the old ACDelcos with these NGK, now going back to ACDelco iridium (likey made by NGK) which is supposed to be the OE plug but also from RA.

 

[mbaker]

I've been reading where some suggest not running platinum plugs in the GM 3800 with wasted spark. Perhaps that is part of the problem? I looked back and the NGK I used were platinum, as mentioned I re ordered AC delco iridium that should be the OE plug.

I had a 97 Pontiac with 3800 and ran standard copper V power NGK plugs with no issues so didn't think anything about the platinums but after reading more maybe that its either standard copper or iridium with these engines.

 

[mk378]

Plugs that are only platinum / iridium on the center will wear on the ground side. This appears as a hollowing out of the ground electrode where the spark jumps. Half of the plugs will do that, since a waste spark system fires one of the plugs on each coil with the reverse of normal polarity. The waste spark system requires plugs that have a platinum / iridium tip on the ground electrode as well. Or use conventional plugs and replace more frequently.

If the gap of all the plugs has increased that is likely the soft metal center of fake plugs burning down. 20,000 miles is about the time frame for that.

 

[PontiacHO]

If gapped with a “go or no go” gauge the center electrode could have been damaged and burnt easily.

 

[Gus_Mahn]

Had the same experience on a Buick Grand National that I’d put Bosch Platinum’s in. The passenger side wore out while the driver’s was perfect. DC Electricity flows from negative to positive, and whichever side is getting stuck with the arc wears faster. Fine tipped center Platinum electrodes do have benefits but don’t hold up to being on the + side of the spark plug.

 

[twX]

If you e-mail photos of the plugs to NGK, they should be able to tell you whether they were genuine or counterfeit. At least, they're able to do that with new plugs. I would definitely do this for the replacement plugs.

 

[kschachn]

I've been reading where some suggest not running platinum plugs in the GM 3800 with wasted spark. Perhaps that is part of the problem? I looked back and the NGK I used were platinum, as mentioned I re ordered AC delco iridium that should be the OE plug.

I had a 97 Pontiac with 3800 and ran standard copper V power NGK plugs with no issues so didn't think anything about the platinums but after reading more maybe that its either standard copper or iridium with these engines.

You need double platinum plugs as the automaker would most likely specify in the owner's manual. My old Sienna is a waste spark system and the manual lists the correct plug.

Also for what it's worth nearly all plugs are "copper" since that is the conductor within the ceramic insulator. The difference is in the tip (and here the ground) material. Cheap plugs use nickel as a tip which is at the lowest end of longevity.

 

[mbaker]

I went back and checked my, I thought they were double platinum but I guess not. I guess that could explain it. New plugs should be here tomorrow, since they are the OE plug I guess that will probably take care of it.