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Old 07-08-2021, 11:09 AM   #1
Hobbes2.2
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Have a Nice Day? FB oil consumption and short block cost

Hello all, it's time for me to finally look into getting a newer Subie. I'm looking for an efficient daily driver with good gas mileage under $9.5k and the 2012-15 Imprezas and a handful of higher mileage XVs fit the bill.

My major concern with these is, of course, the oil consumption issue often leading to a new short block. Of course this raise a number of questions/concerns for me that I've not found answers for in my searches, so I'll list my question here:
1.) Now I've seen talk of dealers covering this, but is that only for cars under warranty?
2.) How will this affect me buying a FB with anywhere from 130k to 200k miles?
3.) Will the shortblock cost be on me, or is Subaru treating it like a recall?
4.) If not, how much will a new short block run me, how difficult would it be to swap out myself? (For reference I've pulled EJ engines and done head gaskets myself).
(added):
5.) Will a stuck PCV valve throw a code? How would I go about checking for/fixing that?

Answers will likely bring more question, so I'll thank y'all in advance for your advice and patients while I do my best to understand these new-to-me engines/vehicles.
~Kevin

Last edited by Hobbes2.2; 07-08-2021 at 11:26 AM.
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Old 07-09-2021, 08:04 PM   #2
Elbert Bass
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Past 100,000 miles you are SOL as far as Subaru paying for a short block for oil consumption. No, normally a clogged PCV will not set a code.

FB engines are a little different than an EJ engine. The process for timing the cams is really odd and involves turning the crank backwards and forwards to install the left bank chain. Get it wrong and you have one side of the engine timed incorrectly. Couple that with the fact that some of the service manuals have the procedure written wrong and you have a real conundrum.
There is a lot more cleaning of Fujibond and reapplying during assembly - just the right amount in the right places - very easy to clog an oil passage and starve a cam.
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Old 07-11-2021, 05:08 PM   #3
Hobbes2.2
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Yeah, that doesn't sound fun. Good to know, thanks for info.

So I do end up need a new block down the road, is there anyway I can verify that the new block won't end up having the same issues? (I guess what I'm asking is: is this oil leakage a ware-and-tear on the block over time, or an actual defect in the block?)

I've read a couple places that say the issue stems from poor quality factory oil rings, and others that say it's a defect in the block itself.

I've also read that Subaru supposedly fixed this issue later in the FB20B line, but am getting conflicting dates on said fix. Some sources say 2014, others 2016. Oh nm on this last one, I just found Blktrax's post on that from back in 2018.

"Block Part# Interchange
10103AC650 = 2014-2015MY Forester & 2013-2014MY Legacy & Outback
10103AC760 = 2013MY XV Crosstrek 2.0L CVT & 2013-2015MY XV Crosstrek 2.0L MT
10103AC750 = 2012-2013MY Impreza 2.0L CVT & 2012-2015MY Impreza 2.0L MT
10103AC660 = 2011-2013MY Forester

Everything after these models have the revised rings from the factory." (cred. Blktrax)

But my curiosity about the block defect vs crap oil rings still exists. It feels like a chicken/egg thing from my knowledge-limited perspective, one problem would lead to the other overtime? Any insight on this? Also curious, any idea what about the oil rings is bad (was it just poor quality material, or poor manufacturing Q/A, or other)?
Same question for the block defect: what was said defect?

Thanks again!
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Old 07-13-2021, 07:01 PM   #4
Elbert Bass
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Quote:
Originally Posted by Hobbes2.2 View Post
Yeah, that doesn't sound fun. Good to know, thanks for info.

So I do end up need a new block down the road, is there anyway I can verify that the new block won't end up having the same issues? (I guess what I'm asking is: is this oil leakage a ware-and-tear on the block over time, or an actual defect in the block?)

I've read a couple places that say the issue stems from poor quality factory oil rings, and others that say it's a defect in the block itself.

I've also read that Subaru supposedly fixed this issue later in the FB20B line, but am getting conflicting dates on said fix. Some sources say 2014, others 2016. Oh nm on this last one, I just found Blktrax's post on that from back in 2018.

"Block Part# Interchange
10103AC650 = 2014-2015MY Forester & 2013-2014MY Legacy & Outback
10103AC760 = 2013MY XV Crosstrek 2.0L CVT & 2013-2015MY XV Crosstrek 2.0L MT
10103AC750 = 2012-2013MY Impreza 2.0L CVT & 2012-2015MY Impreza 2.0L MT
10103AC660 = 2011-2013MY Forester

Everything after these models have the revised rings from the factory." (cred. Blktrax)

But my curiosity about the block defect vs crap oil rings still exists. It feels like a chicken/egg thing from my knowledge-limited perspective, one problem would lead to the other overtime? Any insight on this? Also curious, any idea what about the oil rings is bad (was it just poor quality material, or poor manufacturing Q/A, or other)?
Same question for the block defect: what was said defect?

Thanks again!
Any new or reman short block currently sold by Subaru will have the revised rings. The issue was ring tension. In order to reduce friction Subaru reduce both ring thickness and ring tension in FB engines compared to EJ engines. So much so that in Subaru engine class you could unbolt the rod caps on a new engine, turn the block on it's side, give the rod a nudge and the piston would slide right out of the block. Even a worn out EJ would not do that.

They also went to a lighter weight oil (0w20) so the rings wouldn't "float" and pump oil into the cylinders. The problem was the early engines had so little ring tensions the rings still "floated" and pumped oil into the cylinder where it was burned. They tried replacing rings but they had a problem with techs breaking the rings or scoring the cylinders while installing them. They finally went to replacing short blocks. There never was a block defect, just the lack of "old school" mechanical experience of Subaru dealer techs.
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Old 07-14-2021, 02:10 PM   #5
neg_matnik
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From my experience with FB25 in a 2011 Forester, if the rings are bad, the block will consume oil from day 1. It may get progressively worse over time, but, again, from the get-go, with bad rings, you will notice oil level dropping on the dipstick.
An FB25 short block with good rings will consume very little to no oil.
In fact, once Subaru replaced the original short block of my Forester after 59,800 miles (in Sept 2015), I kept using the 7500 miles oil service interval on the new block and I couldn't detect ANY level drop on the dipstick.
Believe me, I ran the car HARD with that new block; not a drop of oil missing on the dipstick.
Also, I realized that, in comparison, the car wasn't running properly with the old short block, it was definitely down on power because it was guzzling so much oil.
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Old 07-20-2021, 11:17 AM   #6
Jack
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I experimented along the way with my 13 Crosstrek that I bought new. Run the water...I mean 0W 20 oil and from around 15k miles, the oil light would go on somewhere near 4k miles. Run 5W 30 and it never went on and the drained oil equaled the poured in oil, for me 5k miles earlier. I saw a list (maybe google it) with cars that have oil consumption issues and the severity of the problem. Subaru was maybe #15 on the list. These are all caused for the quest to get the MPGs high enough to meet EPA requirements. Loose tolerances and water for oil and sure. You're going to burn some oil. I knew my car was over the spec for oil consumption so to get a new short block, I waited until 94k miles, brought it in, got the test, failed and got a new short block. To be honest, if this had been Honda, who fights to the death before fixing anything, I would have not even cared. One quart or less for 5k miles? Who cares. I would not be concerned with this so called problem in buying an FA or FB.

Now, perhaps my car was unusual or not that bad. If you're drinking a quart every 500 miles, then sure. That's both a problem with the engine in a big way and it's going to kill the cat converter, which is probably the biggest money problem. I suppose for the turbo cars, you could use the broom stick fix on the cat and tune your way out of it. Then use thicker oil and call it a day.
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Old 07-26-2021, 02:19 PM   #7
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New here and battling through the 3 legit replies to even post.
I've acquired an '11 Forester 5-speed for next to nothing and it needs an engine.
Looking for good info on what year/model range FB25's are "the same" as what is in the '11.

I've read various things searching the www about sensor differences and coilpack height differences which seem minor to me. The car comes with the original engine so I can swap whatever is different over to make it work.

I also understand I'm supposed to be engine shopping based on a VIN code.
This happens to be a VIN B car which appears to vault me into the $3k engine league...which is why I ask about what my options are.

Can anyone point me in a direction where there is copious FB25 info?
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Old 09-27-2022, 10:58 AM   #8
kendogg41
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Quote:
Originally Posted by Geebees View Post
New here and battling through the 3 legit replies to even post.
I've acquired an '11 Forester 5-speed for next to nothing and it needs an engine.
Looking for good info on what year/model range FB25's are "the same" as what is in the '11.

I've read various things searching the www about sensor differences and coilpack height differences which seem minor to me. The car comes with the original engine so I can swap whatever is different over to make it work.

I also understand I'm supposed to be engine shopping based on a VIN code.
This happens to be a VIN B car which appears to vault me into the $3k engine league...which is why I ask about what my options are.

Can anyone point me in a direction where there is copious FB25 info?

I'm in the same boat. Supposedly there is a bunch of interchange, but these motors used for ~$3500-$4500 is wild. Shortblocks seem to be in the ~$2k range though like the old EJ motors were.
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Old 07-27-2021, 01:46 PM   #9
Angelus911
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My '12 Impreza drank 1.2 qts in 1200 miles.

IMO, between oil consumption and CVT, I would steer away from high mileage Subie's in that range unless you like to gamble. Hard due to your budget, but if the CVT goes out you're basically looking at $$$$ to replace
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Old 08-10-2021, 04:14 PM   #10
Jack
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In that same 13 XV, I mentioned, our CVT took a dump at 53k miles. Dealer replaced, new is $8k. (I asked). Mine was replaced about 2 weeks before the extended warranty was applied by Subaru. In that 2 week time period, I was actively looking to get rid of the car before the 60k mile mark. Once it came, I exhaled and stopped. Fast forward to today, I just changed the oil and my younger son drives it probably 35-40k miles a year. Now at about 142k miles. NO oil light since 94k mile short block change between oil changes and the CVT has been fine.
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Old 09-07-2021, 08:15 PM   #11
Jack
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I was reading on another forum. Owner owns a Kia that goes through 1 quart every 1000 miles. Kia says that's normal, have a nice day. That's 3 times the amount Subaru fails FB's for. If you buy a used one, use 5W 30 and stop worrying about it.
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Old 11-14-2021, 01:08 PM   #12
Hobbes2.2
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Lots of solid info here, thanks for the feedback all!

Managed to snag a '12 Impreza 'Sport' with 127k (manual trans). Carfax said new longblock at 103k. One owner, dealer maintained, etc. Awesome find really....except the engine is already drinking oil close to the questionable range at times. I did test out the effect of driving style on consumption and the difference was considerable: more than double the consumption. (~0.5qt/1000miles lead foot vs <0.25qt/1000miles feather pedal)
ed: Oil = 0w20 Mobil One

(Fun side story, the dealership owner is a friend of my pop's, and cuts out most of the stealership fees for us, even replaced the bad coil pack for no extra charge. So the carfax was 7 pages, the engine replacement note being near the bottom of page six. Pop and I never actually went in at the same time during the dealings until we went to pick it up, and without communicating on it somehow neither of us brought up the replaced engine. Got it for $9090.xx, tagged, titled, etc. Right after we shook hands, dad mentioned how the replaced engine was really what sealed the deal. The owner stopped mid-line on the paperwork "What??". Seems he never actually read the full carfax himself. Owner: "We already shook on it, didn't we?" "Yep!". In this market, where I live, he could have easily gotten $12k for it. )

Last edited by Hobbes2.2; 11-14-2021 at 01:27 PM.
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