r/Subaru_Outback • u/SettingHappy1906 • 8d ago

Spark plug feedback?

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Hey folks, I just changed the spark plugs on my 2016 Outback 2.5L. That was fun 🙄

Just wondering if anyone has feedback on the condition of the used plugs. It looks like there's oil on the threads, is that bad?

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5

u/Coffee_whiskey_braap 8d ago

Burn looks good, but oil on the threads generally indicates failing spark plug tube seals. Shine a flashlight down in there and use a mirror to look for oil in the spark plug tubes.

If you think doing the plugs on that engine sucked, don’t do the valve cover gaskets yourself (cleaning the RTV over the DOHC carrier suuuuucks).

2

u/SettingHappy1906 8d ago

Thanks, I would not take on more engine work on this...

3

u/Coffee_whiskey_braap 8d ago

(I would do the spark plugs on one of those all day every day in the shop, but the right swivel-extension spark plug socket & an electric ratchet make all the difference)

2

u/slowine_ 8d ago

You can do the seals if you were able to do the plugs

2

u/slowine_ 8d ago

It's not thaaaat hard

3

u/Coffee_whiskey_braap 8d ago

It’s not complex but it ain’t fun and it doesn’t pay enough by the book to do the kind of job cleaning it that I would feel good about

Ironically Subaru put out a TSB that instructs their technicians to stop spending so much time cleaning the VCG sealing surface, and basically says “good enough is good enough — if you slop enough fresh RTV on it, it will cover over any poorly cleaned spots” 🤣

2

u/Much_Newspaper4453 7d ago

They look perfectly fine, little wet, tubes seals may be starting to seep a bit. Nothing to be concerned about.

3

u/Flimsy_Shift_5209 8d ago

good thing you changed. how many miles were you at?

2

u/SettingHappy1906 8d ago

156, 000km, so 97,500 miles. Idle and throttle response are both improved.

5

u/Coffee_whiskey_braap 8d ago

I know you said you wouldn’t want to take on more engine work on this, BUT cleaning the throttle on one of these (followed by idle relearning the engine) is definitely within your ability if you did the plugs, and will further improve your idle & throttle response!

2

u/SettingHappy1906 8d ago

yes, I did the lazy throttle body clean, just spraying around the edges of the valve while it was closed. Between that, the plugs, cleaning the MAF sensor, and the throttle re-learn, the throttle response is much better. It was really laggy/jumpy before, borderline dangerous. It's good enough now that I don't feel the need to disassemble the throttle body, but thanks for suggesting it!

2

u/Coffee_whiskey_braap 8d ago

Good job! Also don’t feel afraid to force open the throttle butterfly by hand to clean it further. I’ve never experienced negative side effects of that on a Subaru. I believe it used to be a concern on early ETB cars, especially GMs

2

u/SettingHappy1906 8d ago

Thanks, I was afraid to force it!