Subaru Outback vehicles (2011-2015) with the FB25 engine may experience excessive oil consumption due to faulty piston rings, leading to premature engine wear and potential damage if ignored.
Reviewed by SubaruReview Editorial Team · Last reviewed 2026-05-15 · Editorial standards
How this problem ranks against the other documented Outback failures — cost, severity, and DIY difficulty at a glance.
| Problem | Years | Severity | Repair cost | DIY |
|---|---|---|---|---|
| Excessive Oil Consumption (this page) | 2011-2015 | Major | $3,500–$5,500 | 1/5 |
| EJ25 SOHC Head Gasket Failure | 1999-2009 | Major | $1,800–$3,200 | 4/5 |
| Catalytic Converter Failure (P0420) | 2010-2019 | Major | $1,500–$2,500 | 3/5 |
| Subaru Outback DPF Regeneration Failure & Clogging | 2010-2015 | Major | $800–$3,500 | 4/5 |
| Outback PCV Valve Oil Leak | 2010-2019 | Minor | $30–$250 | 1/5 |
This is one of several documented Outback problems we track, and it fits inside the broader Engine Guides guide. If you're weighing repair against replacement, cross-check the Subaru repair-cost database and any open NHTSA recalls on your VIN before booking a shop.
The FB25 engine in these Outbacks can consume oil at an accelerated rate, often much higher than expected. This is typically due to poorly manufactured or designed piston rings that fail to properly seal the combustion chamber. Over time, this leads to lower oil levels, which can cause increased friction and wear on internal engine components, potentially resulting in catastrophic engine failure if oil levels aren't meticulously maintained.
The primary root cause is defective piston rings that allow engine oil to bypass the piston and burn in the combustion chamber. The oil control rings, in particular, may be prone to sticking or failing to maintain adequate tension against the cylinder walls.
The primary root cause is defective piston rings that allow engine oil to bypass the piston and burn in the combustion chamber. The oil control rings, in particular, may be prone to sticking or failing to maintain adequate tension against the cylinder walls.
National average $3,500–$5,500.
Difficulty 1/5. Engine rebuild with updated piston rings and gaskets
Frequent need to add engine oil (every 1,000-3,000 miles); Blue smoke from the exhaust, especially on start-up or deceleration; Illuminated low oil pressure warning light; Check Engine Light with P0420 (Catalyst System Efficiency Below Threshold Bank 1) due to oil fouling the catalytic converter; Rough idling or misfires (less common, but possible with severe oil fouling)
Owners typically pay $3,500–$5,500 at an independent Subaru shop, parts and labor included. Our Subaru Oxygen Sensor Replacement Cost guide breaks the job down by parts, labor hours, and where the money actually goes.
The same generation also sees EJ25 SOHC Head Gasket Failure and Catalytic Converter Failure (P0420). Both are documented with symptoms, cost, and a permanent-fix walkthrough — see the full list in the Outback hub.
We rate it 1/5 on our DIY scale. Confident wrenchers can tackle it in a weekend using the permanent-fix steps above. Cross-reference the reliability & common problems hub for related jobs worth bundling while you're in there.
It's part of our Engine Guides cluster, which collects every article covering the same system as this failure.
Same failure mechanism documented on a different Subaru — shares components with this article.
Same failure mechanism documented on a different Subaru — shares components with this article.
EJ, FA, FB, and EZ boxer deep-dives — the engine background this failure sits inside.
Dig into the Problems Database to plan your next maintenance sprint, or browse every model hub for buyer's guides, generation breakdowns, and known-issue lists.