2008 Subaru Outback - heavy oil consumption - Shop may have done wrong?

[trimmike]

My son has a 2008 Sub Outback, 5 spd runs well, adds a quart of oil every 1000-1200 miles since it has 156,000 on it which for this year/model and oil consumption seems normal based on what you read.

The day before he goes to school brings it into shop has the CT emissions check and it passes, has the Connecticut shop change the oil.  4.5 qts 5w30, new Pennzoil filter based on what the receipt says.  Next day leaves on his 800 mile drive to college.  350 miles into his journey CEL comes on steady, cruise control starts to flash and then CEL starts flashing.  He pulls over and pops the hood, engine running rough, lurching all over, a little oil smoke coming from near cylinder 3 .  He turns off engine check oil on and there is none!. 

Gets car towed to New York shop they confirm no oil in crankcase to speak of, there is no obvious leak anywhere under the hood or around the car except what would be expected seepage from the years, nothing fresh.  It sat for 5 days, no oil pool under car.  Coolant level is fine, no oil/frothy mix in anything.  Codes pulled as P0302, P0303, P0028.  First two are miss fire and likely reason for flashing CEL, 028 is oil manifold, bank 2 which was likely due to low oil level

NY Shop says the engine likely blown but need to get into it to diagnose.  I end up spending $500 and get it towed back to CT.  My neighbor is a 30 yr car mechanic so we pull oil plug and about 1qt very dirty black oil comes out.  Pull off filter and, lo an behold, its not a penzoil but a car quest, looks dirty and not very new TBH.  Put some new oil in it, change the filter.  Sounds  bit better but still rocking.  Pull the plugs and all look good except #3, has oil on it.  Compression test show 1,2, & 4 within a few lbs of 175 PSI.  #3 is at 70 PSI.  This is bad..

Back to original CT oil change shop for them to take a look.

Car was running fine before it went into shop for a simple oil change, 350 miles later, miss firing, huge oil consumption w/ no leak (at least 3.5 quarts would show up somewhere one would think?) and compression numbers that suggest the engine needs a rebuild.

What is the likely scenario causing the missfire and no oil??  Shop didn't fill crankcase? Sticky valve pushing oil?.  I think the codes and the dark oil are a symptom of the final issues but not the cause.  What would cause the engine to all of a sudden consume close to 4 quarts of oil in 350 miles?  

[ThosL]

I would scour the online feedback on this shop to see if anyone else had a similar problem; incompetent service rarely happens once, these are lowly paid workers in general.  When I went to the local "Splash" car wash that does oil changes years ago, I had a $250 item in the car go missing during the service!  I had a police report filed and the two employees who worked on the oil change listed their address as the homeless shelter and the other as the oil change place as their "address".  The last person to work on the vehicle is usually the most responsible for what follows.  I had an oil pump go bad on a Subaru once and made the mistake of not having it towed immediately.  

[1 Lucky Texan]

broken ring land? dropped valve guide?

[GeneralDisorder]

Oil smoke near cylinder 3: Failed AVLS solenoid control pressure switch. They like to blow out their diaphragm and leak copious amounts of oil from the switch connector. A Subaru specialty shop will usually notice these are old original style and recommend upgrading them to the updated design. We replace them as a routine every time we do head gaskets. 

It is likely an unfortunate accident that the switch failure went unnoticed and bled out all the oil on a 350 mile freeway run. The switch will only really leak at higher than idle rpm and under a load as the ECU controls oil supply to the AVLS system and only locks in the secondary intake valve rocker to full-lift operation under load. 

GD

[lmdew]

I'll take the simple reliable 90's 2.2 anytime.

[ThosL]

I would trust the experts here, but there remains the possibility of the oil change place messing up.  What is their usual step by step procedure? Pull out oil plug, then oil filter replace oil filter after it is drained then plug then refill with oil.  If an old filter is still in there then the oil change place probably messed up.  

Edited September 4, 2019 by ThosL

[idosubaru]

It’ll be hard to determine whether they made a mistake or you used and blew all the oil or whether it was 75% their fault and 25% not theirs. 

Either way you need a new engine and they’re unlikely to cover it.  Blame is hard to pinpoint and now multiple hands have been into the vehicle, that’s not conducive to good diagnosis and determination for the original shop.  

Oil induced failure probably means lower end issues and not worth putting much money in to diagnose or repair.  Who wants to spend $500 on something that’s got a good chance to blow a rod bearing in 6 months?  

As GD said those oil switches blow oil all the time, I’ve replaced a few myself. 

1 quart every 1,000 miles on a 2008 is usually caused by poor oil changes during some point since mile 1, they don’t routinely use oil but aren’t forgiving either.  

 

[GeneralDisorder]

2008 is definitely worth fixing though - get a reman short block from Subaru. 3 year / 36k warranty. 

And replace those AVLS switches when you do the short block replacement. 

You can't prove the oil change shop is at fault. The remaining oil was black and nasty because the remaining oil was overheating due to there not being enough oil in the system and the complete volume of the pan was being circulated through the engine more often than if the full capacity was present. 

GD

[trimmike]

12 hours ago, GeneralDisorder said:

Oil smoke near cylinder 3: Failed AVLS solenoid control pressure switch. They like to blow out their diaphragm and leak copious amounts of oil from the switch connector. A Subaru specialty shop will usually notice these are old original style and recommend upgrading them to the updated design. We replace them as a routine every time we do head gaskets. 

It is likely an unfortunate accident that the switch failure went unnoticed and bled out all the oil on a 350 mile freeway run. The switch will only really leak at higher than idle rpm and under a load as the ECU controls oil supply to the AVLS system and only locks in the secondary intake valve rocker to full-lift operation under load. 

GD

but no oil visible on the ground nor on the frame.  Or does the leaking diaphragm leak internal and the oil burns?

[idosubaru]

26 minutes ago, trimmike said:

but no oil visible on the ground nor on the frame.  Or does the leaking diaphragm leak internal and the oil burns?

It leaks externally.  Front drivers side top of head and rear passengers side back of the head.

Youll need an engine. call the shop and ask what you should do.

proving beyond a shadow of a doubt whether it was improperly filled with oil or consumption burned it all up will be challenging if that’s the goal. 

[GeneralDisorder]

Could be a failed or aftermarket PCV valve, or a ring/piston issue. If everything is *completely* dry then could have easily been severe consumption. I've seen brand new aftermarket PCV valves eat 4 quarts in 300 miles. It certainly can happen. MUST use only OEM Subaru PCV valves and proper full synthetic oil or the 05+ engines will burn oil when the oil control rings get plugged with varnish and carbon. 

GD

[ThosL]

On 9/4/2019 at 2:34 PM, idosubaru said:

It leaks externally.  Front drivers side top of head and rear passengers side back of the head.

Youll need an engine. call the shop and ask what you should do.

proving beyond a shadow of a doubt whether it was improperly filled with oil or consumption burned it all up will be challenging if that’s the goal. 

You would probably need strong evidence and a licensed professional with a strong record in substantiating bad service.  Somewhat forensic in requirements.  Then do a small claims court action if you have enough evidence.  But without 100% certainty there is no case.  

[logic23]

Really these engines are all junk from the get go.

They have bad ring failures, AVLS sensor failures and the original crappy headgaskets that subaru has been putting on the engines since 99. 

They are over designed and under engineered. 

I see tons of these engines failing around 90K.

After 05 subarus quality dropped off and the cars have tons of issues.

 

 

[GeneralDisorder]

We really don't see a significant difference in 05+ engines. Actually the 00 to 05 engines with the 7mm and 9mm oil pumps have more problems. The AVLS pressure switches are only $24 and insignificant labor to replace. The 05+ engines use the STi rings - they DO NOT tolerate non-synthetic oil and poor maintenance. Give them what they want and they are fine. 

All the Subaru EJ engines back to 90 suffer from eventual rod bearing oil pressure loss due to increased main bearing clearances. This is a function of the block being made of piss-poor cast aluminium that's soft like Parmesan cheese. The main bearing bores in the block oval out and the excessive clearances drop the rod bearing oil pressure. The harder they are run, and the more specific power they are asked to make, the sooner this occurs. One only has to look at the design of the Subaru diesel engine to see that Subaru knows this very well. In these special blocks the main bearing bore's are cut out and replaced with steel or iron inserts to spread the crankshaft load. The design is honestly terrible for longevity. And people wonder why I drive Chevy Small Block's. 1950's tech. Cast Iron. With modern oil technology - virtually indestructible. Subaru engines are like religion - quickest way to become an Atheist is to read the bible. Likewise - tear-down and build Subaru engines for a decade and shine wears off. 

GD

Edited September 12, 2019 by GeneralDisorder

[idosubaru]

8 hours ago, GeneralDisorder said:

All the Subaru EJ engines back to 90 suffer from eventual rod bearing oil pressure loss due to increased main bearing clearances.

Would installing a larger oil pump at 200-250,000 miles mitigate that a little bit?

Are lower powered engines less prone to this...EJ18, EJ22, EJ25, or it's a wash over time/miles?

[GeneralDisorder]

58 minutes ago, idosubaru said:

Would installing a larger oil pump at 200-250,000 miles mitigate that a little bit?

Are lower powered engines less prone to this...EJ18, EJ22, EJ25, or it's a wash over time/miles?

Yes - the lower the power, the longer this process takes. Larger oil pumps don't seem to make any difference because it's not a lack of oil in the bearings, it's the design of the crank and the forces being applied to it due to cylinder pressure. The crankshaft has some amount of deflection - even being forged there are too many journals in too tight of a space. This has several effects - for one the journal width and therefore the ability of the journal to spread the load over a large surface area is compromised, also the lack of material between the journals and the counter-weights makes the crank really.... "floppy" - like a wet napkin. So that over time the natural deflection in the crankshaft deforms the aluminium of the case through repeated hydraulic loading of the main journal webbing. 

I have had occasion to tear down a few low mileage '09-'14 WRX short blocks. The one's that are now part of the class-action suit due to premature rod bearing failure. One in particular came from a 2014 WRX with 24,000 miles on the clock. The car was essentially stock. It had intake, exhaust, and an Access Port running a stage 2 off the shelf map from COBB. Was not driven particularly hard. I tore down the short block and measured the journals with a mic and a bore gauge. Now mind you - the specs are 0.0004" to 0.0012". All three of the center journals were over 0.002" which is WAY out of spec. 

Keep in mind while considering these specs that this is COLD assembly clearance. Which will effectively double at operation temp because the aluminium block expands at twice the rate of the steel crank.

The really insidious part of this is that if you go by Subaru's factory service manual, this is NOT REPAIRABLE. If it measures out of spec the whole engine block goes in the dumpster. Now - in my world we can "fix" it with a line hone. But it will happen again and you can only line hone the case ONE time - after that you have problems with oil pump fitment. The service life is directly proportional to the specific power output and how often full power is used. Obviously if you drive like grandma all the time this will never occur. But most of us don't buy/build 300 AWHP cars to not use it. We generally give people a rough sliding scale - there is no way to know what the service life will be because it depends on usage and mileage is a very poor indicator of WOT full power usage. So if I build you an STI with say... ~500 AWHP  I will make it clear that you can expect 30-40k miles from such an engine. Or two to three race seasons if you are lucky. 

It is also interesting to note that Subaru offers Reman engines - but ONLY for the NA models that make about 165 crank HP. This is because the turbo engine blocks aren't rebuildable without a line hone, which is not a procedure that Subaru recognizes is possible. They KNOW this. Why else would they not offer reman blocks for these cars (there is clearly an enormous demand - in fact they are offering re-manufactured turbochargers now), and why else would the diesel boxer have the main bearing webs replaced with steel inserts? 

These engines were designed in the mid-80's. They were designed with a maximum displacement of 2.2 liters, and a maximum HP of 275 on the EJ20 turbo. Everything that has come after that has been pushing the envelope of the engineering to it's max. 

The fix is simple - but I doubt we will ever see it. Cast the block from iron. Problem solved. 

*edit* - I re-read your post and yes a larger oil pump can help offset the larger clearances. Also thicker oil. On loose engines (and by that I mean we build them with close to the max factory main journal clearance - I usually aim for *exactly* 0.001" when cold) we run 15w50 race oil and 11mm STi oil pumps. On some clapped-out 250-300k EJ25 I would probably run SAE 50 or 60 in it and put on a 12mm pump. Honestly I would. The clearances are usually ENORMOUS on the mains. I've measured high mileage 25D blocks and seen over 0.003" on the center mains. 

GD

Edited September 12, 2019 by GeneralDisorder

[idosubaru]

43 minutes ago, GeneralDisorder said:

Yes - the lower the power, the longer this process takes.

*edit* - I re-read your post and yes a larger oil pump can help offset the larger clearances. Also thicker oil. On loose engines (and by that I mean we build them with close to the max factory main journal clearance - I usually aim for *exactly* 0.001" when cold) we run 15w50 race oil and 11mm STi oil pumps. On some clapped-out 250-300k EJ25 I would probably run SAE 50 or 60 in it and put on a 12mm pump. Honestly I would. The clearances are usually ENORMOUS on the mains. I've measured high mileage 25D blocks and seen over 0.003" on the center mains.

Hey thanks for that GD, very good stuff. 

[FerGloyale]

45 minutes ago, GeneralDisorder said:

 

These engines were designed in the mid-80's. They were designed with a maximum displacement of 2.2 liters, and a maximum HP of 275 on the EJ20 turbo. Everything that has come after that has been pushing the envelope of the engineering to it's max. 

 

GD

I toatlly agree here.  This is what I tell people all the time.

46 minutes ago, GeneralDisorder said:

 

*edit* - I re-read your post and yes a larger oil pump can help offset the larger clearances. Also thicker oil. On loose engines (and by that I mean we build them with close to the max factory main journal clearance - I usually aim for *exactly* 0.001" when cold) we run 15w50 race oil and 11mm STi oil pumps. On some clapped-out 250-300k EJ25 I would probably run SAE 50 or 60 in it and put on a 12mm pump. Honestly I would. The clearances are usually ENORMOUS on the mains. I've measured high mileage 25D blocks and seen over 0.003" on the center mains. 

GD

And I don't disagree here, but I would like to note my own experiences.

I have not had to stop driving a motor due to large Main clearances.  That isn't what fails.  Usually the scraper rings are coked up and it's burning oil, and ROD bearings begin to  suffer form loss of oil pressure (admittedly made worse as mains wear)

Now, unlike the mains, the rods are steel, they don't oval like the case, the hang in until the bearing spins then start knock knock..Who's there...A spun bearing that's who.

With this all in mind, I have rebuilt nearly a dozen 2.2 and a few 2.5 engines.  1 EJ18.  all NA.   Mains in the case have all been mostly in spec, a few slightly over......but It's almost a non issue on NA motors.  I just fit recon the rods and crank.  Thrust clearance is the most important, especially for Manual trans cars.

[GeneralDisorder]

16 minutes ago, FerGloyale said:

And I don't disagree here, but I would like to note my own experiences.

I have not had to stop driving a motor due to large Main clearances.  That isn't what fails.  Usually the scraper rings are coked up and it's burning oil, and ROD bearings begin to  suffer form loss of oil pressure (admittedly made worse as mains wear)

Now, unlike the mains, the rods are steel, they don't oval like the case, the hang in until the bearing spins then start knock knock..Who's there...A spun bearing that's who.

With this all in mind, I have rebuilt nearly a dozen 2.2 and a few 2.5 engines.  1 EJ18.  all NA.   Mains in the case have all been mostly in spec, a few slightly over......but It's almost a non issue on NA motors.  I just fit recon the rods and crank.  Thrust clearance is the most important, especially for Manual trans cars.

I don't really do any NA engines, though I have in the past. Mostly 25D's. I don't recall doing any 2.2's or 1.8's...... mostly because it's not economically viable when they are $400 used. The 25D's I have done the mains were way out of spec. Anything over 2 thou and they are toast IMO. 

As far as the failure mode - understand I am NOT saying the main bearings are failing. They have excessive oil clearance and the rod bearings are ENTIRELY fed off the mains. If the mains are squirting oil out like a garden hose then you won't have any rod bearing oil pressure and you lose the rod bearings - you ALSO lose the piston cooling effect of proper oil delivery to the rods which slings oil into the cylinders and keeps the rings from coking. 

All of this, to one extent or another, is related to excessive main journal clearances. At operating temp a journal with a clearance of 0.001" is going to be 0.002" - which is exactly where you want to be. If the cold clearances starts at 0.002", then at operating temp you are looking at a clearance of 0.003-4" as the aluminium expands more than the crank. This is WAY too much for the narrow Subaru rod bearings to get proper oil pressure. 

GD

[1 Lucky Texan]

could a diesel block be used to build a more reliable turbo gas engine?

[GeneralDisorder]

No - by the looks of the EE20 they are a completely different animal. And interestingly the EE20 suffers from crankshaft's breaking and the block inserts fracturing also. The boxer diesel attempt really didn't work. 

GD

[trimmike]

I am making some headway w/ the shop and they agreed to replace the engine if I buy a replacement he will pick up the labor.  What should I be looking for in a used engine and what should I have done to it before I have them replace it? New head gaskets, valve cover gaskets, AVLS switch, timing chain and stuff it in?  ANything else to keep in mind?  Also, where to buy one?  Suggestions please?  Thanks!. 

[GeneralDisorder]

Just get a reman short block from Subaru - 3 yr/ 36k warranty. About $2250. Don't even bother with used engines. The pricing on used engines and the warranty on the reman's make used engines a poor choice. Read about the main journal clearances that I posted above - you really want to put in a 150k engine? 

GD

Edited September 13, 2019 by GeneralDisorder

[trimmike]

Since the shop I am using is paying to pull the engine and put in a new one they wont rebuild anything inclusive, not that I would really trust them to do a good job so, i am thinking about a re-manufactured engine from gearhead engines (www.gearheadengines.com).  They are quoting a 2.5L remanufactured engine for $2700 after core is returned that includes the 2 way shipping.  Has anyone used these guys before?  based on research they sell a lot of engines and since its completely reman I dont have to do anything but buy it, supply new plugs, wires, cap, as it has new alternator, full gasket set come with (re-use valve covers and oil pan)  Images of the rebuild attached

[GeneralDisorder]

Too much paint. Nope. 

GD