What goes wrong
The positive crankcase ventilation (PCV) system is designed to vent crankcase gases. A failing PCV valve can lead to improper crankcase ventilation, causing oil to be drawn into the intake and burned, or pressure to build up, leading to oil leaks and potential damage to seals and the turbocharger. In severe cases, this can lead to detonation due to oil in the combustion chamber.
Symptoms to watch for
- Increased oil consumption
- Rough idle
- Check Engine Light (CEL) with P051B, P0171, or P0172 codes
- Oil leaks, particularly around valve covers or front timing cover
- Blue smoke from the exhaust on acceleration
Root cause
The PCV valve assembly on early FA24 engines can become clogged or seize due to a design flaw that allows excessive oil vapor to pass through, leading to carbon buildup and restricted operation.
Buy time with these
- • Regular oil changes with high-quality synthetic oil can help reduce the buildup of contaminants in the PCV system.
- • Monitoring oil consumption closely and addressing any increases promptly.
Permanent fix
- Replace the PCV valve assembly with the updated part (if available from Subaru) that features an improved design for better oil separation and flow.
- Perform an oil change and inspect for any other oil-related issues.
Related recalls / TSBs
FAQ
What causes pcv valve failure (fa24)?
The PCV valve assembly on early FA24 engines can become clogged or seize due to a design flaw that allows excessive oil vapor to pass through, leading to carbon buildup and restricted operation.
How much does it cost to fix?
National average $300–$700.
Is this a DIY repair?
Difficulty 3/5. Replace the PCV valve assembly with the updated part (if available from Subaru) that features an improved design for better oil separation and flow.
What are the symptoms?
Increased oil consumption; Rough idle; Check Engine Light (CEL) with P051B, P0171, or P0172 codes; Oil leaks, particularly around valve covers or front timing cover; Blue smoke from the exhaust on acceleration