A view under the valve covers - 145k 2015 Subaru Outback 2.5

[Skeet6]

Here's a look under the valve covers of my (new to me in Dec 2025) 2015 Outback. Needed plugs and found leaking spark plug seals and valve covers. Here's the inside. From the Carfax, looks like most oil changes done at Subaru dealerships. Now on second OCI of Valvoline Restore and Protect.
Mike B

 

[slacktide_bitog]

Looks good

 

[Passport1]

Given what it takes to get a valve cover off, great. Subie on!

 

[matrass]

Looks pretty nice in there .

Good luck on your ride !

 

[SubieRubyRoo]

Driver’s side intake cams always seem to accumulate “junk” the fastest. If you’re using synthetic oils of high quality, this will likely be the only time you’ll need to do the VCs & plug tubes.

Of the used EJs I’ve bought over the years, all of them past 7 years old by the time I got them needed seals by maybe 9-10 years. However, the ones I got before 5 years old and used synthetic only on have not needed them regardless of going past the 10 year mark under my ownership.

My current Ascent will be a good test; I got it right at 6 years of service and 55k; it’s now at 7 years and almost ready to hit 100k. It’s been on HPL exclusively (although different tiers) since right at 56k, so we’ll see how long the proper amount of cleaning agents and seal-swellers will keep this set alive.

 

[Reloader59]

It does look nice in there.

 

[ClutchDisc]

Looks pretty good to me!

 

[CleanSump]

Nice!
I was expecting a sludge thread. I guess I go back to googling Hyundai sludge for that.

 

[Trav]

Looks good, make sure the ground straps from the heads to the frame are in good shape. This is a common problem with big consequences if they are left broken too long.

 

[SubieRubyRoo]

Looks good, make sure the ground straps from the heads to the frame are in good shape. This is a common problem with big consequences if they are left broken too long.

This. Back when I bought my first used EJs, I had read Trav’s numerous posts on rotted ground straps being one of the true root causes of the failure of the EJ’s SLS gasket design. I took heed, did some research, and bought a set of custom OFC 10ga stranded with heatshrunk gold-plated ring terminal ground straps that linked both strut towers, the intake manifold, block, and transmission housing on every “new” EJ I’ve owned since.

Either Trav actually found Subaru’s real issue that wasn’t truly HG since some that had HGs replaced with MLS and then failed again, or he just happened to say that and I just happened to buy 4 more used Subarus with EJ253s on original HGs and they managed to stay that way out of pure luck. But I doubt it on the latter one.

Thanks for helping out, @Trav ! The ~$500 total I spent for those 5 sets of ground strap kits was more than covered by avoiding just one HG replacement job, many times over. Even after all the gasket revisions and even architecture change, are the FA/FBs that susceptible to both ground strap and HG corrosion/erosion issues?

 

[KCHOPS]

I still have nightmares about changing valve covers and oil seals on the EJ25 in my old Impreza. Smaller car and less room, I had to raise the engine to put everything back together .

 

[dkryan]

This. Back when I bought my first used EJs, I had read Trav’s numerous posts on rotted ground straps being one of the true root causes of the failure of the EJ’s SLS gasket design. I took heed, did some research, and bought a set of custom OFC 10ga stranded with heatshrunk gold-plated ring terminal ground straps that linked both strut towers, the intake manifold, block, and transmission housing on every “new” EJ I’ve owned since.

Either Trav actually found Subaru’s real issue that wasn’t truly HG since some that had HGs replaced with MLS and then failed again, or he just happened to say that and I just happened to buy 4 more used Subarus with EJ253s on original HGs and they managed to stay that way out of pure luck. But I doubt it on the latter one.

Thanks for helping out, @Trav ! The ~$500 total I spent for those 5 sets of ground strap kits was more than covered by avoiding just one HG replacement job, many times over. Even after all the gasket revisions and even architecture change, are the FA/FBs that susceptible to both ground strap and HG corrosion/erosion issues?

“Even after all the gasket revisions and even architecture change, are the FA/FBs that susceptible to both ground strap and HG corrosion/erosion issues?”

As the owner of a 2019 Outback, I would love to hear a knowledgeable answer to Subie’s question.

 

[GSCJR]

This. Back when I bought my first used EJs, I had read Trav’s numerous posts on rotted ground straps being one of the true root causes of the failure of the EJ’s SLS gasket design. I took heed, did some research, and bought a set of custom OFC 10ga stranded with heatshrunk gold-plated ring terminal ground straps that linked both strut towers, the intake manifold, block, and transmission housing on every “new” EJ I’ve owned since.

Either Trav actually found Subaru’s real issue that wasn’t truly HG since some that had HGs replaced with MLS and then failed again, or he just happened to say that and I just happened to buy 4 more used Subarus with EJ253s on original HGs and they managed to stay that way out of pure luck. But I doubt it on the latter one.

Thanks for helping out, @Trav ! The ~$500 total I spent for those 5 sets of ground strap kits was more than covered by avoiding just one HG replacement job, many times over. Even after all the gasket revisions and even architecture change, are the FA/FBs that susceptible to both ground strap and HG corrosion/erosion issues?

+1

As soon as I bought my '12 Legacy, I noticed broken grounds, and thanks to @Trav, I knew to take care of those right away.

Looks good @Skeet6

 

[sw99]

The boxer looks good!

 

[mt23]

“Even after all the gasket revisions and even architecture change, are the FA/FBs that susceptible to both ground strap and HG corrosion/erosion issues?”

As the owner of a 2019 Outback, I would love to hear a knowledgeable answer to Subie’s question.

while ground strap corrosion is a contributor to the coating failure of the single layer steel gasket EJ, the main head gasket stressor is the heads and block cooling unevenly to each other.

The EJ block cools quickly compared to the heads. The heads receive coolant from the block so the head gasket is continuously thermally stressed.

The FB block receives 15 percent of coolant from radiator while the heads receive 85 percent of coolant from radiator through dedicated passages. Additionally the FB head gasket is a better designed gasket. I have replaced and seen FB head gasket failure from combustion chamber to coolant but it is not common or widespread at all like the single layered steel gasket EJ.

EJ coolant temperature fluctuates much more compared to FB while driving. You can get a sense of the cooling system stability when watching data from both engines

 

[dkryan]

while ground strap corrosion is a contributor to the coating failure of the single layer steel gasket EJ, the main head gasket stressor is the heads and block cooling unevenly to each other.

The EJ block cools quickly compared to the heads. The heads receive coolant from the block so the head gasket is continuously thermally stressed.

The FB block receives 15 percent of coolant from radiator while the heads receive 85 percent of coolant from radiator through dedicated passages. Additionally the FB head gasket is a better designed gasket. I have replaced and seen FB head gasket failure from combustion chamber to coolant but it is not common or widespread at all like the single layered steel gasket EJ.

EJ coolant temperature fluctuates much more compared to FB while driving. You can get a sense of the cooling system stability when watching data from both engines

Thanks!

 

[slo town]

Those are some wide cam lobes! The cams should last forever.

Scott