Replacing 2011 Subaru Outback Sparkplugs

A

ARCOgraphite

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N.H, U.S.A.
Since its agreeable out, I decided to pull the #2 plug on the old EJ253 engine to see if I need to replace all 4.
These are high dollar NGK Ruthenium fingernail GND plugs for the PZEV engine.
They SHOULD be fine at 65K miles and 9 years.

Well, I pulled an easy one (DS front) and it looks O.K. given it's age.
I may just re-torque them ALL, as this one wasn't very tight; guess this may be due to some oil
in the plug tube - but not a concerning amount.

Sorry for the sub-optimal, cheap cell phone photos. Tried my darndest to get it focused.

What do you guys think?

Spark plug Hole just above the RED Battery Terminal
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A little bit of oil in there
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Looks O.E. to me
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Never seen an insulator that clean
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Gap just under 0.9mm Fancy Ruthenium ground terminal on the NGK SIFR6A11
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Looks good. I’ve only seen spark plugs last that long once or twice before. If they don’t need replacement I say don’t do it.
 
ammolab said:
Really? Only once or twice seen plugs lasting 65,000 miles? Many auto makers call for new plugs at 90-100,000 miles, and they come out looking pretty good.
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I was referring to years actually. Usually most of my customers load their cars with miles so they are only in there for around 5-6 years most of the time. I always replace at 100,000 usually.
 
HangFire said:
NGK Ruthenium came out in late 2018, so it is not OEM for a 2011 Subaru. I'm not clear what the mileage is on these plugs, but it's not the entire mileage for the vehicle.
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Maybe commercially. I know of no other plug that uses the fingernail GND extension laser welded. These are 20.00- dollar each plugs. I've read that Ruthenium and iridium are usually found together.

I have no documentation that there was ever a tune up done, and the plugs have a fair amount of corona burn near the nut. I've NEVER seen GND electrodes look that sharp. The engine appears to be running lean or the plugs too hot given this is a large chamber with essentially a 4" bore
I bet I have a cylinder not functioning well and its affecting the mixture on the other 3. There is some cylinder imbalance and shifter shake.

Frankly, They don't look 9 years in the hole to me either, but again I have no evidence that they have been changed.
 
Do you guys think the oil in the plug well is a concern?
It doesn't appear to be above the plug nut at least.

I think I'm going to have to pull more coils and look in other holes.

I did the easy one, now on to the hard ones!
 
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ARCOgraphite said:
Do you guys think the oil in the plug well is a concern?
It doesn't appear to be above the plug nut at least.

I think I'm going to have to pull more coils and look in other holes.

I did the easy one, now on to the hard ones!
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You don't have to worry about it yet. Chances are the head gaskets will blow before that oil is a concern, and even then, you have to take off the valve cover to do the head gaskets, so you can replace the valve cover gaskets and spark plug tube seals along with the head gaskets.
 
IS_B thanks for responding!

I don't think there have been SUBSTANTIAL HG issues/failures on Subaru EJ253 since the mid 2000's
But I don't have the data in front of me. And I doubt this data exist out side of Fuji H.Q.
unless NASIOC or Subaruforester.org did a survey of members at some point.

In any event, I'm tracking down some rough running. A bit of an engine roll, So I have to do something.

I've done the miserable PCV. It was fine, clean as a whistle.

I was going to adjust valves, as tight EX valves are a major cause of rough running.
But in conference with my Subaru Master in Exeter, he had not see lash issues unless the heads have been rebuilt.

Regardless, the engine roll seems regular, this points to a tight/ burnt / stuck valve issue in my mental "book".

I also have to check and see if I have an engine with the poorly machined valve guide drills
Might have one cylinder with major buildup in the cc..

I have the Subaru TSB, but my vin is not in the affected range.

NUMBER: 02-115-11R
DATE: 01/31/11

- Ken
 
ARCOgraphite said:
Do you guys think the oil in the plug well is a concern?
It doesn't appear to be above the plug nut at least.

I think I'm going to have to pull more coils and look in other holes.

I did the easy one, now on to the hard ones!
Click to expand...
You can usually fix the oil in the plug wells by replacing the seals which are under the valve cover they come with the valve cover gasket sets usually.
 
Yeah, AM, It's bigger job on a subaru since the rocker covers are facing the "frame" rails.

If I decided to replace the cover gaskets, I would do new plugs, and a valve adjustment too. My Subaru master tech talked me out of it.
Not that that would stop me, but its really a job to be done on a lift. I don't even have a garage. And pricey classics and hot rods are jamming up the barn workshop this winter with no room for me!

I guess I'll just have to pull and read more plugs to see if I have a bad hole causing the vibration.
 
ARCOgraphite said:
Yeah, AM, It's bigger job on a subaru since the rocker covers are facing the "frame" rails.

If I decided to replace the cover gaskets, I would do new plugs, and a valve adjustment too. My Subaru master tech talked me out of it.
Not that that would stop me, but its really a job to be done on a lift. I don't even have a garage. And pricey classics and hot rods are jamming up the barn workshop this winter with no room for me!

I guess I'll just have to pull and read more plugs to see if I have a bad hole causing the vibration.
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Leave it to Subaru that’s why I hate working on them. Don’t feel bad I don’t have a garage either I do go to where I went to school occasionally and use the lift I just can’t do it while students are there so it’s usually later in the evening. Hopefully when I get another job I will have a lift again lol.
 
AutoMechanic said:
Leave it to Subaru that’s why I hate working on them. Don’t feel bad I don’t have a garage either I do go to where I went to school occasionally and use the lift I just can’t do it while students are there so it’s usually later in the evening. Hopefully when I get another job I will have a lift again lol.
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Well, I pulled the other three plugs and they all read the same and GOOD, though the gap is tighter than spec at 0.8mm. But with old coils and plugs, no way was I going to open it up.

Now, I'm going to replace the MAF.

But Everytime I take apart the airbox the car runs differently. Almost like there is a unseen split in the post meter plastic intake air tubing.

A bit of a mystery here.
 
ARCOgraphite said:
Well, I pulled the other three plugs and they all read the same and GOOD, though the gap is tighter than spec at 0.8mm. But with old coils and plugs, no way was I going to open it up.

Now, I'm going to replace the MAF.

But Everytime I take apart the airbox the car runs differently. Almost like there is a unseen split in the post meter plastic intake air tubing.

A bit of a mystery here.
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Wow. I’ve had cars run different several times when you take the air box apart when you do that on my van it makes like a sucking in sound then it runs away and revs up.
 
I meant take it apart and put it back together :)
I changed the air filter to a different brand.

After that, the box closed tighter and there was better bottom end grunt.
(Whoa !that sounds a bit like, you know .... )

The other filter must have had thinner plastic around the margin. I didnt measure it.

engine Still have a cyl balance issue and it gets weak when realy warmed up. Ill check the intake bolt tightness next.

Then I will be a valve adjustment - like it or not. Gotta keep those exhaust valves loose enough.
 
ARCOgraphite said:
I meant take it apart and put it back together :)
I changed the air filter to a different brand.

After that, the box closed tighter and there was better bottom end grunt.
(Whoa !that sounds a bit like, you know .... )

The other filter must have had thinner plastic around the margin. I didnt measure it.

engine Still have a cyl balance issue and it gets weak when realy warmed up. Ill check the intake bolt tightness next.

Then I will be a valve adjustment - like it or not. Gotta keep those exhaust valves loose enough.
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Oh ok lol. I’ve never noticed that happening when I change to a different filter.
 
ammolab said:
Really? Only once or twice seen plugs lasting 65,000 miles? Many auto makers call for new plugs at 90-100,000 miles, and they come out looking pretty good.
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In both my Audi's, B5 S4 and B6 A4 both cars called for 40k plug changes. Though my old 95 Pathfinder called for something like 105k if I remember correctly. My 2 new Subarus call for 60k/60m replacement. If I have to follow that schedule, 60 months will happen long before 60k. My wife's Honda goes by the MM and I think it popped on around 105k.
 
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