Welcome to the North American Subaru Impreza Owners Club Monday September 27, 2021
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > FB Series Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 07-08-2021, 11:09 AM   #1
Hobbes2.2
Scooby Newbie
 
Member#: 143350
Join Date: Mar 2007
Chapter/Region: MAIC
Location: Va
Vehicle:
2006 Impreza OBS 5mt
Red

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
* Registered users of the site do not see these ads.

Last edited by Hobbes2.2; 07-08-2021 at 11:26 AM.
Hobbes2.2 is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 07-09-2021, 08:04 PM   #2
Elbert Bass
Scooby Specialist
 
Member#: 283429
Join Date: May 2011
Chapter/Region: South East
Location: Down yonder.
Vehicle:
2016 Fuji Sunfire 03
Silver

Default

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.
Elbert Bass is offline   Reply With Quote
Old 07-11-2021, 05:08 PM   #3
Hobbes2.2
Scooby Newbie
 
Member#: 143350
Join Date: Mar 2007
Chapter/Region: MAIC
Location: Va
Vehicle:
2006 Impreza OBS 5mt
Red

Default

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!
Hobbes2.2 is offline   Reply With Quote
Old 07-13-2021, 07:01 PM   #4
Elbert Bass
Scooby Specialist
 
Member#: 283429
Join Date: May 2011
Chapter/Region: South East
Location: Down yonder.
Vehicle:
2016 Fuji Sunfire 03
Silver

Default

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.
Elbert Bass is offline   Reply With Quote
Old 07-14-2021, 02:10 PM   #5
neg_matnik
Scooby Specialist
 
Member#: 132389
Join Date: Nov 2006
Chapter/Region: BAIC
Location: SF Bay Area
Default

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.
neg_matnik is offline   Reply With Quote
Old 07-20-2021, 11:17 AM   #6
Jack
Add Lightness
Moderator
 
Member#: 13699
Join Date: Dec 2001
Chapter/Region: NESIC
Location: Hopkinton, MA
Vehicle:
2021 Building
It Better

Default

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.
Jack is offline   Reply With Quote
Old 07-26-2021, 02:19 PM   #7
Geebees
Scooby Newbie
 
Member#: 525753
Join Date: Jul 2021
Vehicle:
2011 Forester

Default

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?
Geebees is offline   Reply With Quote
Old 07-27-2021, 01:46 PM   #8
Angelus911
Scooby Specialist
 
Member#: 89967
Join Date: Jun 2005
Chapter/Region: NESIC
Location: MA
Vehicle:
2012 Impreza Sport
DGM

Default

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
Angelus911 is offline   Reply With Quote
Old 08-10-2021, 04:14 PM   #9
Jack
Add Lightness
Moderator
 
Member#: 13699
Join Date: Dec 2001
Chapter/Region: NESIC
Location: Hopkinton, MA
Vehicle:
2021 Building
It Better

Default

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.
Jack is offline   Reply With Quote
Old 09-07-2021, 08:15 PM   #10
Jack
Add Lightness
Moderator
 
Member#: 13699
Join Date: Dec 2001
Chapter/Region: NESIC
Location: Hopkinton, MA
Vehicle:
2021 Building
It Better

Default

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.
Jack is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 03:13 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2021 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.