Coil & Plug replacement for the LFX

Tech discussions on the 3.6L V6 motor (LFX) used in the 2012 & up Caprice.
Post Reply
User avatar
elc32955
System Manager
Posts: 2318
Joined: Thu Nov 29, 2012 4:32 pm
Location: East Central Florida
Contact:

Coil & Plug replacement for the LFX

Post by elc32955 » Mon Nov 14, 2022 6:37 am

My car just crossed over 132,500 mi and for some reason I thought State of NC had swapped coils & plugs around the 50K mile range from my memory of the old maintenance records, so I wasn't too worried about the miles. But... I took a look the other day and..... SURPRISE! It's still running on the original plugs & coil packs.

It's actually doing pretty good for being 35K over the recommended GM plug change interval, no hesitation, stumbling or loss of power that I can detect - so my thoughts are the 12622561 Iridium plugs must have been installed stock. I was also searching for a recommended coil change interval and didn't find one anywhere. So, methinks it's time for a preventative strike. The car doesn't get run too hard with me, I'm not chasing bad guys anymore and no more quick responses to remote radio sites needed after-hours, also I don't race or AutoX the car.

I took a quick look for replacement coils and there's a lot of manufacturers that make product for the 3.6 LFX motor. What surprised me is that MSD does NOT make a coil set for this engine, since the 2012-2015 LS2 Camaro uses the same motor you'd think they'd cater to this crowd. This is what I found for coil interchange from one of the manufacturer sites....

ACDelco-D515C
Airtex-5C1612
Beck/Arnley-178-8435
BorgWarner-E1069
BWD-E1069
CARQUEST-52-1853
Delphi-GN10494
DENSO Auto Parts-673-7300
DIY Solutions-IGN00123
DIY Solutions-IGN00428
Echlin-IC649
General Motors-12590990
General Motors-12618542
General Motors-12632479 (NOTE - OEM part)
IMC-CLS1226
NAPA Mileage Plus-IC649SB
NGK-49018
Original Engine Management-50228
Richporter-C-761
Saab-12590990
Saab-12618542
Saab-12632479
Spectra Premium-C-761
Standard Motor Products-UF-569
Suzuki-3340078J00
Suzuki-3340078J01
Suzuki-3340078J02
Suzuki-3340078J03
TRQ-ICA61585
Walker Products-921-2109
Wells-C1555

For coils & plugs from some research I did, I found the best references for the NGK and the OEM GM/ACDelco products. Seems down under the best plug kudos go to the NGK 90117, supposed to be superior to the GM Iridium as this PN is for the NGK Laser Iridium plug. I can tell you it's more expensive across the board, but there just may be more margin on the product, dunno. Very good recommendations also for the stock GM Iridium plug, p/n 12622561 (AC Delco 41-109).

Also just doing an EBAY search there appear to be many Chinese-based vendors selling coils in pretty-looking ACDelco boxes at discount prices, along with US vendors carrying the same product graphics with a number of items. Those ALL smell of counterfeit coils. Even ACDelco has a web page on how to detect counterfeit parts. Disappointing and confusing for non-knowledgeable people. Last time we got into discussion on counterfeit parts here was over duplicated Tech-2 scan tools that did wonky things....

Hey S/C'd, what's the deal on the two superseded GM coil part numbers, are they really the same coil?

Thanks
Eric
System Manager and your tour guide for the day. 2015 Caprice 3.6, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, 2016 Camaro V6 rims, otherwise bone stock for now.

s/c'd cav
Posts: 1215
Joined: Mon May 30, 2016 8:12 am
Location: PHOENIX AZ

Re: Coil & Plug replacement for the LFX

Post by s/c'd cav » Mon Nov 14, 2022 5:08 pm

12590990(list 292.11) ,12610626(list 303.78) ,12618542(list 83.50) , 12632479(current # , list 112.98) , looks like there was 4 numbers total , first 3 are all discontinued #s

with as widely used , and amount of years the 3.6 twin cam has been around , having only 4#s isnt to bad , id have to guess the 2 expensive ones to the 2 less expensive ones were a supplier change

and the AC delco # is tied to the 12632479 # , so they would be the same part inside the box

User avatar
elc32955
System Manager
Posts: 2318
Joined: Thu Nov 29, 2012 4:32 pm
Location: East Central Florida
Contact:

Re: Coil & Plug replacement for the LFX

Post by elc32955 » Tue Nov 15, 2022 2:46 am

Thanks!! Also adding to the coil list, Accel makes a yellow-top coil set - their p/n #140569. It's pricy at #80.82 ea, also anecdotally they have had a few failures on these reported by discontented customers, causing people to revert back to their stock ACDelco coils. So guess the jury is out on this product's reliability.

Eric
System Manager and your tour guide for the day. 2015 Caprice 3.6, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, 2016 Camaro V6 rims, otherwise bone stock for now.

s/c'd cav
Posts: 1215
Joined: Mon May 30, 2016 8:12 am
Location: PHOENIX AZ

Re: Coil & Plug replacement for the LFX

Post by s/c'd cav » Tue Nov 15, 2022 3:42 am

as far as coil go , there is nothing out there better than the OE units , failure rate on the aftermarket is probably several hundred to 1 , lol

people have made over 1000whp on the stock ls coils

User avatar
elc32955
System Manager
Posts: 2318
Joined: Thu Nov 29, 2012 4:32 pm
Location: East Central Florida
Contact:

Re: Coil & Plug replacement for the LFX

Post by elc32955 » Tue Nov 15, 2022 6:15 pm

Yep, they have a good reputation with users from what I can find. But, here's the question. What is the life expectancy on those coils? It's not listed in the vehicle maintenance schedule, is it a case of just waiting until you start seeing misfires & codes or is there a life expectancy figure on those from the manufacturer? It's a pretty quick thing to swap the coils, but I just couldn't find a hard figure anywhere.

Thanks
Eric
System Manager and your tour guide for the day. 2015 Caprice 3.6, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, 2016 Camaro V6 rims, otherwise bone stock for now.

s/c'd cav
Posts: 1215
Joined: Mon May 30, 2016 8:12 am
Location: PHOENIX AZ

Re: Coil & Plug replacement for the LFX

Post by s/c'd cav » Tue Nov 15, 2022 6:18 pm

elc32955 wrote:
Tue Nov 15, 2022 6:15 pm
Yep, they have a good reputation with users from what I can find. But, here's the question. What is the life expectancy on those coils? It's not listed in the vehicle maintenance schedule, is it a case of just waiting until you start seeing misfires & codes or is there a life expectancy figure on those from the manufacturer? It's a pretty quick thing to swap the coils, but I just couldn't find a hard figure anywhere.

Thanks
Eric
replace them as they fail , or are damaged

they arent like a regular plug wire

Post Reply