Any Spark Plug Gurus out there?

[TollKeeper]

So did a tune up on the Envoy.. 5.3 with just about 200k on the clock.

Here are the plugs.. 1 plug has me really concerned.


She drove just fine on the way to work. The stumble at idle is gone. New plugs are 41-962. Plugs that came out are 41-110? That doesnt seem right?

It was hard coming out, and even worse going back in with the new one. It sealed up good, and I dont have any mis-fires. But its still concerning. Opinions?

Edit: The stumbling might also have been the intake hose. Right where it goes into the throttle body, half the tube was folded under, and allowing un-metered air in.

 

[linneje]

I am not a guru, but yours look pretty similar to mine (I think mine actually looked a little worse) when I took mine out. The 5.3 really generates a lot of heat. The boots on my wires were practically welded on when I changed them out, and that was about 160000k (when I became the owner). I haven't had any problems with the new plugs over the 120000k that I have had them in for. Of course I put Delcos in again.

 

[Chickenhawk]

They look perfectly fine.

Years ago, we carefully gapped our plugs and even gapped them when they came out of the box. Gapping modern plugs is not only a waste of time, but can damage the plugs. With the modern plugs and ignition systems, they can jump tremendous gaps without misfires, as can be seen by your worn plugs.

Personally, I would pull out those 41-962 platinum plugs and replace them with the 41-110 iridium plugs, especially if you want to keep it running smooth for the next few years.

 

[TollKeeper]

I would be scared to do that honestly.. Look at the pics of the plugs again, specifically the second pic. The old plug on Cylinder #1 brought out threads (furthest left plug in that picture). Was a pain to get out, and a royal pain to get back in. None of the stores in my area had Iridium plugs either. One store had 41-103... Thats when I asked him what engine he had selected, "well they only come with one engine". Wow.

Edit: But I did try to get Iridium's. Autozone, NAPA, CarQuest, Advance Auto, O'riellys. None had them, and was a 5 day order. Since I had already pulled the plugs when I found this out, I went with the ACDelco Double Platinum's

 

[linneje]

I actually put double platinum in when I did mine years ago (I think because that's what I could get quickly at the time) and they have been running fine for 120000k.

 

[Chickenhawk]

Based on that, I think you are fine.

 

[Mooseman]

One plug in those pics has me concerned about all the others. In your second pic, last plug on the right, it looks to have the normal look of an ACDelco plug, is different than all the others and is worn the most. Maybe that one is original and the others are either fake or a different number. Maybe it was never replaced?

 

[Mike534x]

One plug in those pics has me concerned about all the others. In your second pic, last plug on the right, it looks to have the normal look of an ACDelco plug, is different than all the others and is worn the most. Maybe that one is original and the others are either fake or a different number. Maybe it was never replaced?

That happened with my old TB Ext. When I pulled the plugs to change them to Iridium's (had the iridium's made by champion) I found that Plug #4 (or whichever one is blocked by the strut) was still the factory original Platinum. They all looked just as worn as Tollkeepers, aside from the original worn plug.

 

[TollKeeper]

One plug in those pics has me concerned about all the others. In your second pic, last plug on the right, it looks to have the normal look of an ACDelco plug, is different than all the others and is worn the most. Maybe that one is original and the others are either fake or a different number. Maybe it was never replaced?

Thats the easiest plug to replace, the rear passenger side.. But who knows what the dealer did when they did the original tune up back in the day..

 

[TollKeeper]

One plug in those pics has me concerned about all the others. In your second pic, last plug on the right, it looks to have the normal look of an ACDelco plug, is different than all the others and is worn the most. Maybe that one is original and the others are either fake or a different number. Maybe it was never replaced?

Wow... Good eye. It was a factory OEM installed plug, completely different than the other 7.