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Discussion Starter #1
Ok guys I took the plunge and changed out the spark plugs. I can almost say I am the first person to ever change the sparkplugs on a CTS because I called 6 Cadillac Dealers and none of them had done it since the stock ones are suppose to be good for 100k miles. Well here are the pictures take a close look at the difference of the stock platinum plugs and the Iridium plugs I put in. The stock ones look like shit after only 20k miles on them. If any of you guys are going to do it PM me and I will give you my cell phone number just in case you have any questions during the install. I felt a big difference in responsiveness after changing the plugs.




New Gaskets in place



You will have to remove the plastic missing in the below picture to get to 1 of the bolts.

 

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Discussion Starter #3

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Jeez...I'd rather change the plugs in my C5. It isn't easy, but you don't have to disassemble the engine to get to them.
 

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Discussion Starter #5
PODunk said:
Jeez...I'd rather change the plugs in my C5. It isn't easy, but you don't have to disassemble the engine to get to them.
I enjoyed doing it makes you get to know your engine a lot more. I noticed you h ave a 03 CTS if its a 3.2L it might be different were you dont have to remove the intake manifold.
 

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Was there a noticable difference in the gapping of the plugs, it didn't look too bad, but they did look rather fouled, expected though, the way we push our cars

(Cadillac says 100k miles) they probably mean when grandma drives the car to the store and back, never once reaching 3k rpm's
 

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Discussion Starter #8
AsAkAs said:
Was there a noticable difference in the gapping of the plugs, it didn't look too bad, but they did look rather fouled, expected though, the way we push our cars

(Cadillac says 100k miles) they probably mean when grandma drives the car to the store and back, never once reaching 3k rpm's
Actually I got a feeler guage the Part Number I provided are pregapped for our 3.6l CTS which is .044 inches and it was pretty close on a couple of them I opended them slightly to get them to .044 inches. I agree they say 100K for normal uses meaning you dont push your car beyond 3k rpm. I was amazed my spark plugs looked like shit only after 20k and also iridium is 4mm you notice the difference in plugs according to Denso it shaves .07 second of the 1/4 mile. I dont doubt it after changing mine with all the mods I have I didnt feel my engine shifting perfectly but after installing these plugs I feel its perfect every single shift. tomorrow night I will make a good video of my car going 0 to 90 I am too drunk right now so I am not gonna try it. honeslty biggest upgrade is the headers you can actually hear the engine breathe I am not sure if you seen my post were I showed a picture of the stock manifold they are a POS.
 

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Looking at the old spark plug, it looks like it is tapered around the sealing area with no compression seals. The new one looks they have a compression washer (seal). Did you have to modify the new ones or they fit like it is?
 

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Discussion Starter #10
rydr2 said:
Looking at the old spark plug, it looks like it is tapered around the sealing area with no compression seals. The new one looks they have a compression washer (seal). Did you have to modify the new ones or they fit like it is?
They fit perfectly.
 

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In order to change the plugs on a FWD Cad Allante, you need to drop the engine cradel in the front and lower the entire engine/transaxel assembly to get at the 4 back spark plugs.
 

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Hmm, I wonder if changing plugs would help my gas milage. I can barely break 20 most of the time. Im at 68,000 miles.
 

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SD,I know you are a helo mechanic, so this may be obvious... but did you do your headers and catl, sway/roll kit, spark plugs and lowering springs install yourself?
 

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Discussion Starter #14
pjohnesq said:
SD,I know you are a helo mechanic, so this may be obvious... but did you do your headers and catl, sway/roll kit, spark plugs and lowering springs install yourself?
I did everything except the headers and cat. I was working long hours and didn't have time for it.
 

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Marine,

Your old plugs look fine IMHO. They have a nice light brown color on the insulator, the electrode tip is clean (definitely not fouled), and they don't look worn at all. Pull you new plugs in 10,000 miles and I'll bet they look the same. You should see the plugs that come out of my carburated '65 Mustang every 30,000 miles.

If they were running rich, the electrode insulator would be sooty black. Too lean and you could have blistering and burnt electrodes with large gaps. If they were fouled, they'd likely have a solid piece of black carbon between electrodes (I've pulled many of those in my carburated cars). If they show any of these signs it typically has nothing to do with the plug, but rather the engine tune (mixture, timing, etc.). The plugs only show the symtoms of engine tune and are a great indicator. With the complex computer controls nowaday, there's not much 'tuning' for us to screw up. If they were wet and black everywhere it means bad oil rings, but that's typically only with very high mileage engines.

The platinum is meant to keep the electodes close to stock gaps (they don't wear like normal steel) for many miles. The new iridium plugs are even better. The only thing that I'm not sure I like is that the new iridium electrode tip is about 1/3 the size of the original platinums (which is about 1/3 the size of normal plug electrodes), so there's that much less material there to burn off as they wear. Only time will tell how they wear and last, but I can tell you from 30 years of tuning cars, both of these plugs are MILES better than what was out there even 10 years ago.

BTW, I'm sure ALL of us are anxious to see more dyno runs of your new mods. That car hauls A$$ in that video.
 

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That looks like a P.I.T.A... Looking at those intake runners a port & polish would be a good idea. :D
 

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I picked up on what Ody saw on the electrodes. They are smaller in diameter. The more surface area you have for the spark is usually considered better. I wonder what the thinking was by the engineers in selecting a smaller electrode?:hmm:

That's a lot of work Marine and we all appreciate what you share with us. I've got 30,000 miles on my plugs but I think I'll wait a bit more. Have you given any thought to the spark plug wires? They can usually be improved upon.
I did give you some luv pts for sharing though.:D
 

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Discussion Starter #18
odysseus said:
Marine,

Your old plugs look fine IMHO. They have a nice light brown color on the insulator, the electrode tip is clean (definitely not fouled), and they don't look worn at all. Pull you new plugs in 10,000 miles and I'll bet they look the same. You should see the plugs that come out of my carburated '65 Mustang every 30,000 miles.

If they were running rich, the electrode insulator would be sooty black. Too lean and you could have blistering and burnt electrodes with large gaps. If they were fouled, they'd likely have a solid piece of black carbon between electrodes (I've pulled many of those in my carburated cars). If they show any of these signs it typically has nothing to do with the plug, but rather the engine tune (mixture, timing, etc.). The plugs only show the symtoms of engine tune and are a great indicator. With the complex computer controls nowaday, there's not much 'tuning' for us to screw up. If they were wet and black everywhere it means bad oil rings, but that's typically only with very high mileage engines.

The platinum is meant to keep the electodes close to stock gaps (they don't wear like normal steel) for many miles. The new iridium plugs are even better. The only thing that I'm not sure I like is that the new iridium electrode tip is about 1/3 the size of the original platinums (which is about 1/3 the size of normal plug electrodes), so there's that much less material there to burn off as they wear. Only time will tell how they wear and last, but I can tell you from 30 years of tuning cars, both of these plugs are MILES better than what was out there even 10 years ago.

BTW, I'm sure ALL of us are anxious to see more dyno runs of your new mods. That car hauls A$$ in that video.
Supposively according to Denso the Iridium plugs shaved .07 seconds from 0-150km which is only 92.3Miles whichs cars get to higher speeds than 92mi when running the 1/4 mile so according to them it would shave almost 1 second of your time. They even have dyno charts in the box and everything.
 

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Discussion Starter #19
Has anyone else followed my lead? Just Curious
 
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