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**2014 CTS4 Sport Wagon-Luxury**
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Discussion Starter · #1 ·
...I replaced my OEM spark plugs yesterday at 65K plus miles and I don't think the old ones looked too bad but the new ones seem to have improved drivability...I've never been one to tout new spark plugs as providing much improvement and I have had a habit of replacing them before they should be due...this is the first time I can report I've felt a real difference.

there has been earlier talk of what are the correct plugs for our cars and mine is a 2014 Sport Wagon that came with AC Delco Iridium 41-109/GM 12622561 bought from RockAuto.com...these have the same markings as the OEMs I removed and what is listed in my owners manual...

while out for my shakedown drive I noticed that slight hesitation upon first accelerating is gone and that the car feels peppier...I realize I only have the 3.0/LFW but I'm liking this so far...I also am aware that I might just be experience the placebo effect of a new part but as I mentioned I have never had this reaction before from doing the same...

here are some pics of the plugs I removed...everything looked good under hood and I used a touch of dielectric grease on the plug boots and coil connectors...

601157
601158


feel free to comment on the condition of these plugs...I have read online that my plugs may show evidence of the occasional use of gasoline additives...I have used Lucas Fuel Injector Cleaner and Gas Treatment (I won't any more) and Chevron Techron in the past...

Bill
 

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Magoo—2012 Cadillac CTS Luxury, Opulent Blue, plus many more, see signature.
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Those plugs don't look too bad. They are a little worn (from what I can tell with the pics, comparing the gaps to the thread pitch which is a known measurement and good for scaling). I typically change out AC Delco Iridium plugs around 60K miles and usually notice a slight improvement in performance when I do. If you try to stretch them to the rated 100K+ miles, you'll often get misfiring bad enough to set codes by then.

Those brown stains at the base of the insulator on the outside of the plug are "corona staining" and are caused by oil or other contaminants in the spark plug well (outside the cylinder). They generally have no negative effect on performance, and are not any indication of "combustion gas leakage" which they are sometimes misdiagnosed as. If there was oil in any of the spark plug wells, you need to address that by replacing gaskets/o-rings on the valve covers. Sometimes just dielectric grease will cause a bit of that "corona staining," so it's nothing to worry about.

For fuel additives, Techron occasionally is a good thing. Personally, I run a bottle of Techron in the tank every time I change the oil filter (which is 2 to 3 times as often as oil changes with good synthetic and the OLMS). It will prevent sulfur deposits on the fuel gauge sender in the tank, and as difficult as replacing that is on these cars, that's a worthwhile thing. You can buy it at the GM dealerships as GM Part # 88865595 ("Fuel system treatment plus - gasoline", superscedes 88861013) or you can buy the Techron bottles at your FLAPS or online. There's an AC-Delco part number as well. GM TSBs related to fuel gauge sender issues actually call for that additive/cleaner/treatment. All other additives are to be avoided. The SDS for Techron and the GM part are identical, so it's the same stuff in the bottle, only the bottle and label are different.

Oh, and "Top Tier gasoline" only for these direct injection engines.
 
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'14 CTS-V LongRoof; '16 ATS-V Sedan,' 04 Trailblazer 4x4; '10 CTS LongRoof gone but never forgotten
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Techron usually available at Costco.
 

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**2014 CTS4 Sport Wagon-Luxury**
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Discussion Starter · #4 ·
thanks for the feedback...I buy Techron Complete Fuel System Cleaner when on sale at the local auto part stores...whomever has the best price...I have first hand experience with the sulphur deposit cleaning abilities when it was an issue with C5 Corvettes and the fuel tank gauge sender...fixed the issue in one pour...tried it again on a similar issue with an F150 pick up...also cleared in one bottle...I'm a believer...

thanks also for the info on corona staining...all my park plug wells were clean and dry appearing as new and the gaskets were pliable and appeared good too...I expected it to look worn, used but it looked great...

upon removal, all plugs still show .040 gap...on RockAuto's site they show .040 for the correct gap and warn not to regal plugs but the info they show for the plugs under "more info" lists .043...I left them as gapped from the factory...all were protected within their individual boxes by a rigid plastic sleeve...

Bill
 

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Discussion Starter · #5 ·
I'll report back if my fuel economy drops a few MPGs or I gain 100 horsepower...or find any deals on whiskey... ;)

Bill
 

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2013 Cadillac CTS 3.6 Sport Luxury
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I have noticed some misfire at idle or low revs / low load recently.

Maybe 3 times the last two weeks. Like going on 5 cylinders. If I lift the gas pedal and throttling again it is gone. No flickering of engine light.

CTS has 117.000 km on the odo and got all intake cleaned at the 100.000 km service.

Could it be spark plugs?
 

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2009 CTS 3.6L DI rebuilt to FE3 J55 G80 3.42:1
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I have noticed some misfire at idle or low revs / low load recently.

Maybe 3 times the last two weeks. Like going on 5 cylinders. If I lift the gas pedal and throttling again it is gone. No flickering of engine light.

CTS has 117.000 km on the odo and got all intake cleaned at the 100.000 km service.

Could it be spark plugs?
Hard to say, but 117km is enough to justify spark plug replacement.
 

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I have noticed some misfire at idle or low revs / low load recently.

Maybe 3 times the last two weeks. Like going on 5 cylinders. If I lift the gas pedal and throttling again it is gone. No flickering of engine light.

CTS has 117.000 km on the odo and got all intake cleaned at the 100.000 km service.

Could it be spark plugs?
Could very well be plugs if they've not been replaced or even something as simple as a bad tank of gas.
 

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Discussion Starter · #9 ·
I think it was worth it to change mine around 65K/104+ km...

Bill
 

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Magoo—2012 Cadillac CTS Luxury, Opulent Blue, plus many more, see signature.
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I'm thinking I need to do this for Magoo soon. Nothing horrible, but 10-15 misfires per hour showing in the Mode $06 tests on her. She's got almost 180K miles now, and they were done at least twice. I'll have to check dates and mileages on the service records I have.

One question I have, both for @silversport and for the others here, does everyone change the plug boots (the boot and spring under the coil pack) when they change the plugs? I see that Denso (the OEM for the coils) doesn't offer a replacement boot, they only have the entire replacement coil unit. I'm not sure I want to go with the AC Delco "Professional" series parts for that (too much low grade Chineseum in the "professional" series parts).

I doubt there's any need to replace a coil unit unless/until it fails. Or do they have a limited service life as well?
 

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Coils rarely fail and I would only replace springs/boots if plugs didn't clear up an issue.
If you don't like Delco Professional, then you really don't like Delco Advantage.
 

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GMPartsnow is pretty reasonable for OEM parts. If you can get them, and they aren't back-ordered.
 

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Discussion Starter · #13 ·
I did not replace mine but inspected them...I have experience replacing boots and springs on my sister's Corolla (needed to as I pulled one off that wouldn't release from the old plug) and my former F150 (due to misfires and flashing check engine light)...

inspecting mine I found the rubber like material to still be as pliable as new (they had a plum color to them) and the spark plug tubes were clean and dry and also appeared as new...other than adding a touch of dielectric grease to the spark plug connection as well as to the coil electric connection (there was none there previously) was all I did beyond replacing with the same type and number plugs as I removed (AC Delco 41-109 Iridiums)...

I have about 150 miles on the new plugs since replacement and the car is running just fine and I am seeing no faults reposted to my BlueDriver scanner...

Bill
 

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Discussion Starter · #14 ·
Denso 6716307 - $29.97 are listed for the 2014 3.0 Luxury Sport Wagon with all other numbered parts being the same as what's listed for your 2012 Luxury (it's a 3.0 right?)...I don't know why those don't show for your year on RockAuto's site but if they are what you are looking for and you want them...don't forget the always helpful 5% code if buying from Rock Auto...

Good luck,

Bill
 

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Magoo—2012 Cadillac CTS Luxury, Opulent Blue, plus many more, see signature.
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Denso 6716307 - $29.97 are listed for the 2014 3.0 Luxury Sport Wagon with all other numbered parts being the same as what's listed for your 2012 Luxury (it's a 3.0 right?)...I don't know why those don't show for your year on RockAuto's site but if they are what you are looking for and you want them...don't forget the always helpful 5% code if buying from Rock Auto...

Good luck,

Bill
Yes, I have the 3.0L V6 (LFW) engine.

Denso 671-6307 appears to be the number I was looking for. Thanks, @silversport

Weird catalog glitch there. Even Denso's own website has the same glitch. They list the same part # (671-7300) for the coils on a 2014 Cadillac CTS with the 3.0L, and list the 671-6307 as the boot kit for that year. But for the 2012 Cadillac CTS with the 3.0L engine, they do not list a boot kit. I sent them and email to let them know about the glitch, and to verify that there's not some other weird difference that makes the 671-6307 not work on my 2012.

I would pull the coils and inspect the plugs and boots, but with my rotten luck, I'll tear a boot doing that. That's why I like to at least have the replacement boots in my hands when I dive in for replacing the plugs.

If you don't like Delco Professional, then you really don't like Delco Advantage.
Delco Advantage is one I totally ignore.

The "professional" line has some stuff in it that's worth getting. Ignition parts (wires, coils, coil pack boots) aren't something I get from the "Professional" line. Got burnt more than once with spark plug wire sets in that line that arrived as "kits" with "some assembly required." They weren't priced low enough to justify me having to cut the wires to length and crimp the terminals, and the materials weren't nearly as good as the "original equipment" plug wires in those applications. They weren't even as good as some of the lower priced, fully assembled competition, some of which were assembled in the USA with quality (USA sourced) cable.
 
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I have noticed some misfire at idle or low revs / low load recently.

Maybe 3 times the last two weeks. Like going on 5 cylinders. If I lift the gas pedal and throttling again it is gone. No flickering of engine light.

CTS has 117.000 km on the odo and got all intake cleaned at the 100.000 km service.

Could it be spark plugs?
Could be. I pulled mine around 160,000 kms and they were still in good condition (in fact, I kept them!). When I replaced mine, I notice a little oil around a couple of them but I disregarded it as the car didn't have an oil retention problem. Still, a year or so later, I noticed a slight misfire situation (light - maybe 20 misfires in one cylinder per driving cycle) that caused an occasional hesitation but only in certain circumstances.

My story is chronicled in this thread: 2010 CTS AWD 3.6L DI misfire with no code?. I am not suggesting that this is your problem. I will say that you should run a mode 6 to see which cylinders are misfiring and how many misfires. Post that information here and then we can talk.
 

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Magoo—2012 Cadillac CTS Luxury, Opulent Blue, plus many more, see signature.
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Following up with the response I got from my "contact form" question to Denso.

My message was:

Category: I'm a consumer and I have a product question.
Message: I'm looking for the coil on plug boots for the 3.0L V6 engine in my 2012 Cadillac CTS with the 3.0L V6. None are listed for my engine. When I look for the 2014 Cadillac CTS with the 3.0L V6, I see that it uses the same direct ignition coils (673-7300) as my car, and it lists 671-6307 as the Direct Ignition Coil Boot Kit. Will the 671-6307 work on the COP ignition coils on my engine?
Year: 2012
Make: Cadillac
Model: CTS
Engine: V6 3.0L
VIN: <redacted>
<snip out the personal details>
The response I got was short and evasive.

Since I don’t have a confirmation of the “boots” fitting a different vehicle, I cant confirm or deny it. If you decide to use the boots anyway, you might want to confirm the old boots match to the new boots.
I guess I just have to buy them and try them.
 

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Tremendous non response from customer no-service.
 
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I had a wife that asked me that ONCE.
 
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