The FB25 replaced the head-gasket-prone EJ25 in 2011 - and introduced a new problem: piston ring oil consumption. The Yaeger v. Subaru class action (settled 2016) extended warranty coverage on 2011-2014 Outback, Forester, Legacy, and Impreza. 2015+ models got revised rings.
Mixed. 2011-2014 FB25 burns oil from piston rings (class-action covered). 2015+ FB25 has updated rings and is much more reliable. Direct-injection FA-series carbon issues still apply.
Same root cause as Toyota 2AZ-FE - oil-control ring channels are too narrow and clog. Yaeger v. Subaru class-action settled 2016. Subaru extended warranty to 8yr/100K on affected VINs.
View P0507 Diagnosis →Active Valve Control System solenoids fail or stick from oil sludge. Throws P0011/P0021 and cam position codes. Often cured by an oil change with a thinner viscosity.
View P0011 Diagnosis →Subaru issued TSB 11-167-15 for cracked flexplates on CVT-equipped FB25. Causes intermittent ticking that follows engine RPM.
The newer direct-injection FB25 builds carbon on intake valves by 60K-80K. Port-injection FB25 (2011-2018) does not have this issue.
View P0171 Diagnosis →Standard age-related boxer-engine weep on both banks.
Knock sensor on top of the block fails. Throws P0328.
View P0328 Diagnosis →Run a free AI diagnosis tailored to your exact Subaru. Get the most likely cause in under 30 seconds.
Run a Free Diagnosis on My FB25100% free · No signup needed · Powered by NHTSA + AI
2011-2014 FB25 in Forester, Outback, Legacy, Impreza - high oil consumption rate. 2012-2014 CVT models with risk of cracked flexplate.
2015+ FB25 (updated rings). 2019+ FB25 direct injection is solid mechanically but needs walnut blast at 80K.
On a 2015+ FB25, expect very low ownership costs - just oil changes and a $400-$800 carbon clean at 80K if it is the DI version. On a 2011-2014 with documented oil consumption, you may need ring service ($2,500-$3,500) unless the class-action goodwill applies.
If your FB25 is throwing a check engine light, these are the codes most often associated with the problems above. Click any code for full diagnosis steps and typical repair costs.
The 2011-2014 FB25 has too-narrow oil control ring channels that clog with carbon and stop scraping oil off the cylinder walls. Subaru redesigned the rings starting in 2015.
Yes for affected 2011-2014 vehicles under the Yaeger v. Subaru settlement (2016) - extended powertrain coverage to 8 years/100,000 miles. Most claim periods are now closed but some goodwill remains.
2011-present Forester 2.5L, 2010-present Outback 2.5L, 2010-present Legacy 2.5L, 2012-present Impreza 2.5L (some markets), 2018-present Crosstrek 2.5L, 2019-present Ascent (different displacement but same family).
2015+ FB25 is dramatically better - no head gasket problem and fixed oil consumption. 2011-2014 FB25 traded the EJ25's gaskets for oil consumption - a different problem of similar severity.
2015+ examples are routinely going 200,000+ miles with regular service. 2011-2014 examples vary widely depending on whether oil consumption was addressed early.
Timing chain - one of the biggest improvements over the EJ25's timing belt. No scheduled replacement.