OEM spark plug(s) for 2001 Suburban 5.3L

JLeosnow · December 5, 2006

I picked up a set of spark plugs from the dealer today for our 2001 Suburban 1500(5.3L) and they gave me part# 41-985 / 12571164. I checked all of them out of the box for gap and they are all pre-set to .040. I looked under the hood on the emission decal and it does not list a part# for the plug used in this vehicle but they do provide a gap spec. of .060.

My question is...... A) Do I have the correct plugs for this vehicle? B) If yes, do I re-gap these plugs to .060 like the emission sticker suggests?

Thanks much,

-John

GM-Tech · December 5, 2006

Gee, with the 100,000 rating on the plugs, I can't remember the last time anyone in our shop did a "tune-up." Few vehicles with that kind of mileage come to the dealer for tune. I guess they do it themselves or go to an independant... or just ignore it.

Seems to me you're not supposed to modify the gap as it comes out of the box. Might even be a note on there to that effect, but I don't recall. I don't know part numbers so can't help you in that respect. Sounds like the wrong ones to me. I'd definitely go by what the emission label states.

icecoldtexan · December 6, 2006

I picked up a set of spark plugs from the dealer today for our 2001 Suburban 1500(5.3L) and they gave me part# 41-985 / 12571164. I checked all of them out of the box for gap and they are all pre-set to .040. I looked under the hood on the emmision decal and it does not list a part# for the plug used in this vehicle but they do provide a gap spec. of .060.

My question is...... A) Do I have the correct plugs for this vehicle? B) If yes, do I re-gap these plugs to .060 like the emmision sticker suggests?

Thanks much,

-John

<{POST_SNAPBACK}>

I just replaced my plugs with dealer supplied ac delco plugs. The gap out of the box was .040

I read on the ac delco web page and other web sites that state you do not adjust the plug gap. I think I even saw a bulletin about it on the alldata web site.

I put them in with the .040 gap and haven't had any problems. My label under the hood also specifies a .060 gap.

2001 2500HD 6.0l

JLeosnow · December 6, 2006

Thanks to all who responded. From what I am reading in the attached link I must have the correct plugs...

-John

Link

C & A s Dad · December 6, 2006

My 02 and I believe your 01 came from the factory with NGK plugs gapped at .060. For some reason AC came out with their plug and changed the gap. If you want the OE plug, you need to buy a set of NGKs. When I pulled my OE plugs they were co labled NGK on one side and AC on the other. I do not have the part # of the NGK with me right now but you can see my earlier posts concerning this.

I am sure you will be fine with the ACs but I have read some posts where the owner claimed a less than smooth idle when they changed to the .040 gapped AC plugs.