Just a thought as I saw a few CVT coolers cause problems. They also look like oil in coolant. Just something else to check.

When you get it back together, you seem like the type to keep an eye on your coolant and oil. Hopefully it can be just OLD coolant as Subaru's Long Life is supposed to be changed at 136K. Maybe this wasn't done and with a lot of hot running, it just broke down.

But I also see all that GOOP on every part you removed.

Best wishes on your repair. Hope you get to enjoy it other than turning wrenches on it.

Edit after thought ..... MAYBE someone replaced the blue Long Life with old green glycerin .... and they don't mix well, especially if they didn't flush the old completely.

 

Thanks for the clarification on "walk away" as you mean sell it and not return it since you bought it in May and it's no longer returnable. ferret is smart and is on the right path with his recommendation.
Thoughts: What if the radiator was leaking then someone poured two or more bottles of Bars Leaks into the system. That would account for the brown color. You are obviously replacing the radiator before making the 'sell' decision, right? When you do this work be sure to do a coolant gas test on the cooling system to be sure of the head gasket issue. Wait on the heater core but do the rest. It may open up with clean coolant and a new radiator and hoses. And be sure to use Subaru blue coolant. If you live in GA (?) there's an excellent shop in the S.E. part of the state called Royalty Auto Service. There are lots of helpful YouTube videos produced from this shop. Mr. Subaru is another source.

 

P.S. If you do dump it then you'll need to at least stop the white smoke pouring out the tail pipe. ATP AT-205 is an excellent leak sealer for fluids like engine oil, diff., power steering. K-Seal is good for cooling system leaks. You have more work to do before you'll get your answer to sell or keep this Subu.

 

If coolant enters a cylinder (usually indicated by white smoke from the exhaust), the spark plug in that cylinder may appear unusually "clean" due to the steam cleaning effect of the coolant.
You can remove all the spark plugs and compare them to see if one looks noticeably different from the others. A single clean plug may indicate a coolant leak into that specific cylinder.


Another possible source of coolant&oil mix—if the vehicle is equipped with a CVT—is the CVT heat exchanger.

 

You probably have two issues here. Unlike the old EJ engine there are no oil passages across the head gaskets on FA/FB engines. All oil is fed independently to each head and the case from the timing cover/oil pump. head gasket fail will get coolant in oil pan but not oil in coolant.
You most likely have the upper oil pan o-ring failure (oil in coolant) and most likely a failed headgasket (coolant in combustion).
My best forensic guess without hands on is that the damaged radiator issue caused an overheat bad enough to fail head gasket. Someone may have used stop leak. In fact that contaminate in the coolant may be stop leak unless you are sure it is oil.
Since you don't see smoke until the engine is warm (common for a MLS gasket early fail) you may not be able to verify the head gaskets with a cylinder leakage test on a cool engine, but I would do it just to see if it showed a fail between cylinder(s) and cooling system. Also Lemotan is right about the steam clean effect, if you have a borescope you could look in the spark plug hole and compare piston tops - there will be less or no carbon on a piston in a leaking cylinder.

 

Thanks folks - really appreciate the feedback.

• Interesting... so the goo in the coolant could just be Stop Leak! There was a lot of gooey / stringy particulate matter in the waste coolant.
• I have a buddy with a scope. I'll investigate the piston heads.

The math I'm trying to do is whether or not I can pull it / reseal it (head gaskets, all RTV, oil pan o rings) and get another reliable 30-50k miles out of it ...or should I cut bait and sell it as a mechanics special for $3k or so?

At the moment it sounds like the engine is still likely recoverable, so I'll press on!

 

You have resources and motivation so your decision to keep going is a good one. It's not always about the money. With your next used vehicle you'll know that a better inspection is warranted. Sometimes it's worth having a second set of eyes on a used one. There are great check lists in print and video about every test/ inspection that needs to be done before forking over the dough.

 

Scoping to come. In the meantime, here’s a snap of the waste coolant that has sat for a while. Looks like it’s NOT oil in the coolant as it has not separated, but Bars Leak or something similar as suggested earlier.

So: how did the head gasket come to fail? A cracked radiator leading to an overheat by prior owner? 🤔

 

Unless the previous owner listened to some BAD Advice about the older EJ25 engines that did have head gasket failures and tried to Prevent it on the newer FB engines which do not exhibit this. Just another Guess.

I would just clean out as best you can, fill it fresh with new oil and the proper coolant and keep an eye on it. After which you can make your decision to keep it or sell it.


EDIT .... Even after refilling, if there was that much crap in the cooling system, you still may see SOME come thru after driving. Just be prepared for that weather it alarms you or not.

 

Interesting. So I’ve flushed the system at least 3-4 times with water. It is currently filled with distilled water.

I will start it up and run it on idle for about 30-45 seconds but it still puts out more white smoke than I’d like to subject my suburban neighbors to 😅

Are you suggesting that it may still be driveable? I don’t quite understand how coolant could be getting into the exhaust without there being a head gasket breech.

 

You might also consider a used engine. When working in a garage we sourced from LKQ with good results. When I put in a 2015 Crosstrek CVT ( since you have a Limited ), I come up with a few from 2015 Imprezas and Crosstreks... all under $1500.

LKQ Online

LKQ Online is North America's largest online provider of recycled original equipment (OE) auto parts for cars and light-duty trucks requiring collision or mechanical repair.

www.lkqonline.com

 

Thanks for the tip!

 

The radiator cap hard crystalline deposits isn't oil since oil doesn't dry out and form crystal deposits in motor vehicle environments. The worst diesel/bunker oil powering container ships is semi solid, needs to be heated to liquify it before feeding into those huge diesel engines. K-seal is one brand of cylinder head gasket sealer and one video shows a youtuber pouring it into the radiator; brown fluid. A popular tv duo (Roadkill) used this sealer to see how cheap they can get away with driving a sketchy engine to a destination for some abuse on an off road. These are last ditch repairs with no guarantees of short or long term use. My guess is cylinder head gasket damage. Past threads can help with model years of affected engines.

Even before bore scoping, removing spark plugs should reveal coolant droplets on them since water/coolant doesn't mix well with fuel or oil. You should see which plugs are fouled and may determine which cylinder head(s) were damaged. Bore scoping will show more inside each cylinder. Another guess is when this brown coolant concoction was drained, flushed with water, sealer that hardened around the damaged head gasket may have broken off and allowed coolant, in this case plain water, to re-enter cylinders and turn into steam. Water is incompressible but will turn into steam when the air fuel mixture ignites under compression pressures.

 

No matter how you go about getting it back on the road, get the proper coolant in there ASAP. Distilled water will just make internal engine rust and corrosion worse!

 

Before you going spending un-necessary money. It is most likely NOT the head gaskets causing this. A true head gasket failure on a FA/FB engine is very, very rare.

So what is it you ask, there are a few things that can cause oil to enter the cooling system. Since you said your car has no other symptoms it is most likely due to the 3 coolant passage o-rings located in the upper oil pan that allow oil to enter the cooling system. This is a common failure AND a common misdiagnosis for head gaskets.

To repair the engine need to be pulled, front timing cover removed and upper oil pan removed. Then replace the 3 o-rings, reinstall the upper oil pan and timing cover (and associated seals, o-rings & sealant). Flush the cooling system and you'll be good.

I've repaired countless Subaru's with this same "issue" this way, all are still running great and loyal customers after other shops gave them head gasket quotes.

Mr Subaru talks about it here:

 

Thanks Opie! Love to hear from pro Subaru wrenches. I am aware of this and was planning on replacing those upper oil pan rings as well since I’ll have the engine out.

But riddle me this: how am I getting white smoke out of the tailpipe if it’s not also the head gasket?

We determined earlier that there is at least some sort of Stop Leak in the coolant. I cannot actually confirm oil in the coolant.