Subaru Engine Smoke + Power Loss Points to PCV System

Had similar symptoms on my 2015 Subaru WRX with the gasoline engine. The rough idle and power loss pointed to a clogged positive crankcase ventilation valve. The smoke during acceleration was a clear indicator of oil being pulled through the system incorrectly. The crankcase ventilation system needed thorough cleaning and valve replacement. Found significant oil residue buildup blocking proper ventilation. This caused increased pressure in the crankcase, forcing oil past the seals and into the combustion chamber. This is a serious issue that requires proper attention. Leaving it unchecked can lead to increased engine wear, damaged seals, and potential catalytic converter problems. The repair involved: Cleaning the entire ventilation system, Replacing the PCV valve, Checking connecting hoses for damage, Testing crankcase pressure After the repair, the idle smoothed out immediately and the smoke issue resolved completely. The engine regained its normal power and the check engine light cleared. Regular maintenance helps prevent this from recurring. Would recommend getting it checked soon, as continuing to drive with these symptoms risks more expensive damage.

Thanks for sharing your experience with the PCV system repair. I had nearly identical symptoms on my Exiga last year, the smoke and rough idle were quite concerning. The fix cleared up my malfunction completely. Been meaning to ask, do you recall the total repair cost? Also curious if youve had any new leaks or related issues pop up since the work was done? My mechanic mentioned something about monitoring the crankcase pressure periodically but I havent noticed any problems myself.

Just got back from having this ventilation issue fixed at the shop last week. The total came to 360€ for the complete repair, this included replacing the faulty valve and cleaning out the whole system. Since clearing up that malfunction a month ago, the engine runs perfectly with no idle problems or leaks. My mechanic did a thorough job testing the crankcase pressure after the repair. No issues have come up since then. The smoke is completely gone and power delivery is back to normal. While monitoring pressure is good practice, a properly fixed PCV system shouldnt need frequent checks. The valve replacement seems to have fully resolved the ventilation problems.

After dealing with this issue for weeks, I finally got it sorted at my local shop. The whole repair came to 420€, bit more than expected but worth every cent. The PCV valve was completely clogged, just as suggested here. The maintenance took about 3 hours total. The mechanic showed me the old parts, the ventilation system was badly gunked up with oil residue. No wonder there was smoke coming from the exhaust. They cleaned everything, replaced the valve, and tested the system thoroughly. Been driving for 2 weeks now and the difference is night and day. No more rough idle, no smoke during acceleration, and power is back to normal. The engine light cleared right after the repair. Definitely glad I got it fixed before any serious damage occurred. For anyone reading this later, dont wait if you notice similar symptoms. A simple PCV system issue can lead to bigger problems if left unchecked. Getting it properly diagnosed early saved me from more expensive repairs down the line.