Another Spark Plug Thread

[BatsTDK]

Going a bit cross eyed trying to figure out which plugs to get. ACDelco has a nice rebate right now, but it looks like they don't make the original iridium plugs for my truck anymore. The manual says 41-974, but when searching that, I get cross referenced to 41-162, but I also see people talking about 41-110... so I'm just plain confused now. Also, are double platinum plugs worth it over regular platinum?

 

[drakon543]

if you want the iridium just get the ngk one its a great spark plug.

 

[BatsTDK]

if you want the iridium just get the ngk one its a great spark plug.

I’m fine with the platinums, I am just confused about which to get.

 

[George B]

If I had to do over I would get the NGK. I have the 41-162 and myself and others swear the idle is rougher than with our original plugs.

 

[Fless]

I used AC Delco 41-962 double platinum - as recommended by GM - with no issues. Runs smooth.

 

[BatsTDK]

I used AC Delco 41-962 double platinum - as recommended by GM - with no issues. Runs smooth.

Gah… another part number! This just keeps getting messier lol. And to add even more, I pulled one plug to inspect, and it’s an ACDelco 6!

 

[Fless]

My '04 5.3 came with 41-985s. I inquired directly to ACDelco about the unavailability of those, and this is the response I received:


Regarding your inquiry for spark plug for VIN [cut], we show the correct part number to be 41-962. The 41-985 are discontinued and they do show to supersede to 12621258 which is not available and they are no longer recommended for your vehicle. The engineers have made the change to the new spark plug.

If you have any other questions, please feel free to contact our experts at the ACDelco support center by dialing 1-800-ACDELCO (223-3526).

We appreciate your business.

Regards,

ACDelco Internet Response Team

EDIT: 2008 TSB here: https://f01.justanswer.com/edhunt0r/88cbc3c3-4ce4-40b9-9e0e-5749f0bcc19e_Avalanche+plug+gap.pdf

 

[BatsTDK]

My '04 5.3 came with 41-985s. I inquired directly to ACDelco about the unavailability of those, and this is the response I received:


Regarding your inquiry for spark plug for VIN [cut], we show the correct part number to be 41-962. The 41-985 are discontinued and they do show to supersede to 12621258 which is not available and they are no longer recommended for your vehicle. The engineers have made the change to the new spark plug.

If you have any other questions, please feel free to contact our experts at the ACDelco support center by dialing 1-800-ACDELCO (223-3526).

We appreciate your business.

Regards,

ACDelco Internet Response Team

EDIT: 2008 TSB here: https://f01.justanswer.com/edhunt0r/88cbc3c3-4ce4-40b9-9e0e-5749f0bcc19e_Avalanche+plug+gap.pdf

Thanks for that. Seems like ACDelco/GM engineers can't make up their mind about which plugs are best lol. I think I'm going to go with the 41-110 iridium plugs. After rebate, I can get all 8 for about $25.

 

[mattbta]

I've put the 41-110 in mine twice now and the yearly rebate Delco runs is nice. Once due to original mileage, the other because I was swapping heads.

They seem to do fine, but contemplating going with a non iridium or platinum one just for grins. Truck doesn't get driven enough that changing every so often is a big deal. #8 isn't nearly as hard as my old f-bodies. I used to run NGK TR6's or TR55's just because they were colder. Haven't figured out what I'll go with next for certain.

 

[BatsTDK]

I've put the 41-110 in mine twice now and the yearly rebate Delco runs is nice. Once due to original mileage, the other because I was swapping heads.

They seem to do fine, but contemplating going with a non iridium or platinum one just for grins. Truck doesn't get driven enough that changing every so often is a big deal. #8 isn't nearly as hard as my old f-bodies. I used to run NGK TR6's or TR55's just because they were colder. Haven't figured out what I'll go with next for certain.

Curious... why are you considering switching from the iridiums?

 

[mattbta]

Curious... why are you considering switching from the iridiums?

Boredom. I don't have any misfires with these...but the idle is a tad rough. It's likely not spark related, but easy enough to rule out. It's probably trans/convertor or motor damage from coolant intrusion due to cracked heads. But it's cheap and checks an attempt off the troubleshoot list.

 

[BatsTDK]

Boredom. I don't have any misfires with these...but the idle is a tad rough. It's likely not spark related, but easy enough to rule out. It's probably trans/convertor or motor damage from coolant intrusion due to cracked heads. But it's cheap and checks an attempt off the troubleshoot list.

Interesting. I heard people were getting a smoother idle with the iridiums. I'd be interested to hear your findings when you do the change.

 

[easymoney]

This is crazy but i have 225k miles on my tahoe and pretty sure it has the original spark plugs. I did buy it used 2ith 110k on it but the lady i bought it from said she had only changed tires on it and transmission had gone out and wasjust rebuilt. The plugs are 41-985…the plugs still work but im worried thry might be rusted in there so i want to change them out but cant buy what was in there…

 

[easymoney]

I had the same issue cant buy the parts that came in it. Had 41-985 ac delco….they lasted over 224k on them as did the wires. Starting having a little issue with rough idle…..i replaced with ngk-1465 i figure motor wont last that long but running very smooth. I couldnt buy the oem 0445 ac delco wires either with the same part number. Thats annoying i went back with ac delco 9748HH wire set..