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Threads on the old plug look rusty?
That's heat. Normal. They're actually an exact representation of what the service manual says is perfect.
 

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Interesting. I understand it on the sparky side facing the combustion chamber, but the threads are what stuck out to me. When tightly sealed I wouldn’t think they’d change color that much. In comparison I pulled plugs from my 98 Bimmer with 231k mi on it and the end looked a little more grey but the threads were clean. No idea how many miles are on those plugs.
 

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So what you’re saying is the majority of us will be taking it to the shop to change the spark plugs? 😂 (myself included)
Yep. I am debating doing the rest of mine, or letting someone else. I don't have any of my real tools anymore.
 

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Interesting. I understand it on the sparky side facing the combustion chamber, but the threads are what stuck out to me. When tightly sealed I wouldn’t think they’d change color that much. In comparison I pulled plugs from my 98 Bimmer with 231k mi on it and the end looked a little more grey but the threads were clean. No idea how many miles are on those plugs.
The heat makes them change color down the plug. I'm also not sure how much of the plug sticks into the top of the chamber, but, as you can tell, there's a LOT of threading on it. Mine matches 2(1) Normal - which of course makes me happy, especially after the abuse they've went through, including judicious use of @COBB Tuning's 93 tune. ;)

4448
 

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I haven't yet. I'm having a shop do it. I don't have the necessary tools to lift the engine.
 

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That's unfortunate the spark plug change is so difficult. I like to do a lot of my own maintenance, but doesn't look like I'll be doing spark plugs if I buy an Ascent!

BTW, how much did it end up costing you to have them changed? If you don't mind my asking... I know "YMMV" with that question.
 

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I pay the same as the rest of you (well, the rest of you who pay NY Metro Area prices)... but I've still avoided having it done. Soon, maybe. I get a quote this week.
 

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Are many subarus like this where its difficult to change the plugs? I remember on my old pilot 3 plugs were against the firewall and it was totally blind. A mirror and some swivel ratchets and extensions got it done but I thought that was a pain. But, I only put 7k miles a year on my ascent so Ive got time ;-)
 

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All Subies have horizontally opposed boxer motors. Some have just enough space that with the right size sockets and extensions, and a few scraped knuckles, you can change your plugs. I think the Ascent is the most difficult I've seen.
 

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BTW, how much did it end up costing you to have them changed? If you don't mind my asking... I know "YMMV" with that question.
I had mine done and the cost was $350 at my dealer. I really don’t know if this is a good or bad price. Like others I usually do my own but the degree of difficulty did not appeal to me. Hopefully by the time I need them again someone will have documented the easy way to change them.
 

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Better than the first quote I got.
 

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I had mine done and the cost was $350 at my dealer. I really don’t know if this is a good or bad price. Like others I usually do my own but the degree of difficulty did not appeal to me. Hopefully by the time I need them again someone will have documented the easy way to change them.
Given the amount of work it sounds like, I'd guess $350 is a "good" price...
 

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I had mine done and the cost was $350 at my dealer. I really don’t know if this is a good or bad price. Like others I usually do my own but the degree of difficulty did not appeal to me. Hopefully by the time I need them again someone will have documented the easy way to change them.
Given the amount of work it sounds like, I'd guess $350 is a "good" price...
 

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The heat makes them change color down the plug. I'm also not sure how much of the plug sticks into the top of the chamber, but, as you can tell, there's a LOT of threading on it. Mine matches 2(1) Normal - which of course makes me happy, especially after the abuse they've went through, including judicious use of @COBB Tuning's 93 tune. ;)
The COBB tune is likely the REASON they have that nice brown/tan and evenly distributed color. Look closely though the you'll see that the electrodes are rounded off which tells me that they are wearing and losing effectiveness. The sharp edges are typically the easiest places for sparks to be generated.

Also, does COBB recommend a tighter plug gap when running their tune? It'd suck to have to do it on original plugs, but if you are changing them you may as well make that adjustment before you throw them in!
 

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It's not unusual for some spark plugs to be harder to replace due to position and obstructions these days. Not much space left in the engine compartment compared to "back in the day" The Grand Cherokee with the 5.7L Hemi V8 is challenging on one side..and there are two plugs per cylinder. :) Fortunately, I don't worry about such things 'cause I don't wrench.
 
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The COBB tune is likely the REASON they have that nice brown/tan and evenly distributed color. Look closely though the you'll see that the electrodes are rounded off which tells me that they are wearing and losing effectiveness. The sharp edges are typically the easiest places for sparks to be generated.

Also, does COBB recommend a tighter plug gap when running their tune? It'd suck to have to do it on original plugs, but if you are changing them you may as well make that adjustment before you throw them in!
Hi, let me try to respond to everything...

In the color training photos, that evenly distributed brown/tan is the color we of course want, but, no, it's not because of the COBB tune. The vast majority of my miles are on the factory tune. 😉 Figure 50,000 miles of driving was factory tune.

Yes, mine are definitely wearing, but, as I said, they look pretty good. Remember, these are not plugs that are mid-life. They're currently well over their life and should have been changed nearly 10,000 miles ago - and were 681 miles from end of life when I took the pic. So, in relation to the number of miles, they "look good".

COBB recommends no changes to stock whatsoever, when running any of the OTS tunes.
 

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Gotcha...I guess what I meant is that the OEM tune would likely yield plugs that were slightly darker (rich) than the Cobb tune. A custom tune would likely yield an even lighter color...but the most important thing is the evenness of it. That is likely due to DI...as its almost impossible to do with port injection...then you end up indexing plugs to get the gap facing the intake valve, etc. Fun times!

My last forced induction DI engine was the 3.5L Ford Ecoboost in my F-150. I had that thing making 400 wheel hp and 550+lb-ft at the wheels. That thing ate plugs like it was no one's business, so its good to see we can get 50k to 60k out of a set considering the PITA it is to change them. Plugs/ignition systems have come a LONG way but are a vital system to an engine running right. I still remember the days of going out on the road, doing a nitrous run and shutting the engine off and coasting to a stop, only to pull a plug and read what was going on during the nitrous run!
 

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Yeah, I am really impressed with how the things have done on mostly factory tune miles. It's a FAR cry from what my plugs in older cars used to look like in half the miles, lol!
 
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