Factory stock LNF spark plug images pulled @ 67k miles
 

The plugs came out dry to the touch and the car was put away a day and a half ago immediately after it's 8th intake Seafoam job. Please tell me your thoughts on the appearance. All plugs measured as sloppy .034 that a .035 slip gauge wouldn't clear without force. Replacement OEM plugs all measured as a perfect .033" to my hands via slip gauge.

https://www.cobaltss.net/forums/memb...-034-12926.jpg

https://www.cobaltss.net/forums/memb...-034-12927.jpg

https://www.cobaltss.net/forums/memb...-034-12925.jpg

Dial torque wrench indicated 45 ft-lbs to break(memory needle pegged just over 550 inch-lbs fwiw) and it was close enough to the same for each that I will call it 45-ft-lbs. After breaking them each quite smoothly spun out by hand with just the extension and socket. Just had the torque wrench calibrated :)

Car was driven normal and not allowed to idle before shut down. #4 in person in much more obviously gray than plugs #1-#3 but the images color is a bit misleading I feel as the first three all are about the same flavor of tanish brown with #2 being slightly more brown than the odd plugs. It is just on the verge of perception, I am sure the color variance is due to the quality of my cell phone's camera.

PS: I first noticed a problem requiring seafoam around 60k miles and cleaning the valves via the intake manifold the first time cleaned up the random but getting progressively more common loss of power @5,500 rpm up) performed every tank of gas or so since with less blueish blackish smoke emitted for continually shrinking amounts of hard drive time required to dissipate the smoke from exhaust.

They look fine to me.

I was thinking the coloration on the ceramic at the base was from my having pressure washed off the top of the engine after each winter's sand had been removed from the road and the wand pushing a little water past the ungreased from the factory boot. I am not worried about it as the plug wells were absolutely clear and clean of anything. Maybe that wasn't the cause. It is the only thing I can think of for it but I'd love a correction on what that is/was.

That's from heat.

That discoloration on the ceramic is from heat and a very light film of oil.

Nothing to worry about as long as the spark plug holes aren't actually filling with oil.

Good plugs!

Those plugs look as they should. Almost perfect to me.

What you noticed as performance and drive-ability issues which seemed to clear up with seafoam (and possibly why the plugs varied just ever so slightly in color) was carbon build up on the valves.

Seems to me like everything is hunky-dory now :twothumbs

Yea, I agree those plugs actually look great for the mileage. I mean look at the tips where the iridium is. You still have a good amount. Beside discoloration they are fine. Those are the Denso's right?

67k miles!

They look awesome.

Surprised they made it so long. I replaced mine every 10k or so and they looked like that. lol.

haha.. Same here. That along with my b1s1 o2. Preventative maintanence ftw! :guns:

8th seafoam? Lol

8 seafoams? Because I found out LNF owners did this as preventative maintenance all along why I rack up almost over 60k before I ran into a problem. I decided t okeep doing it at sub 1k mile intervals until it seemed like there was no more coming off and since others mentioned a worry about fouling, I figured at the last seafoam I would change the plugs and see the results above.

The only thing I noticed post plug change was that boosting up a long hill, the engine seemed to shudder for about 3 seconds. I started in 5th and at 45. I ran it up to 80. I re ran that hill and have tried to reproduce but I am chalking it up to the ecm learning the new gaps and completely clean electrodes.

The plugs have the NGK ITLR5D number on them but were the factory installed ACDelco 41-108's.

Didn't even think of it being the dielectric grease cooking for the discoloration

I think I am going to change the plugs at 50k intervals from now on with a cleaning @ 25k. I am not a fan of exposing the cylinders any more than necessary and knowing my luck, I'll crossthread that aluminum head... its my first (Al head) so I am pretty paranoid about everything where the plugs are concerned. I really don't like the torque spec being 15 ft-lbs.

Did a couple of 5.7 second (bluetooth and torque) 0-60 runs back to back in the Seattle 80 degree weather on what's left of the factory contis. They have over very easily 20k miles and 4/32nd lowest reading tire, the rest are all at a smidge above 5/32. I completely destroyed a set of conti extreme contact DWS and Eagle GT's and only put the CSC2's on at summer solstice and remove in October or so.

And the center electrodes? That is not gray you see at the end of taper before the tip, its clean metal. There is a black spec at the top that i presume is the iridium and the platinum catch on the ground electrode body is clear aside from some light build up around the perimeter

For the amount of miles you've logged, they look great! However, are you tuned or modded? I can't tell exactly from the pics, but it looks like your heat range is off by 1. Your threads should be discolored 2-3 threads down, not the 5 or 6 that it looks like. Timing looks about right too.

agreed. excellent.

100% stock configuration

those plugs look fine. They look better than mine when I pulled them at 60k miles. That discoloration is definately from heat. Pressure washing (aka getting water on the plug would make the metal of the nut look like it had clay on it. heres a pic.

http://sphotos-b.xx.fbcdn.net/hphoto...19259049_n.jpg
old spark plug next to a new one. notice the nut looks like there's white paint on it? thats from water.


the browning of the gap bridge is from seafoaming and other additives found in gas.

Your shudder is from bogging the car at 45 mph in 5th.. downshift is what it's saying. Especially going uphill.

Can't believe how good those plugs look at 60k!

Thanks! I was curious if i had been to aggressive with the wand.