Car: 2009 Subaru WRX
Cobb Accessport (Stage 2+...low wastegate duty map)
Cobb SF Intake & Airbox Combo
Process West TMIC
SPT Turbo Heatshield
Turbo XS High Flow Catted Downpipe
Turbo XS Catback Exhaust
The only recent changes have been a change in ambient temps with the end of summer beginning of fall.
When my engine is cold, the BPV and/or intake do not sound as though they are operating properly. This happened overnight coincidentally with the change in ambient temps. I now have a flutter that I didn't have before. I would describe it as a hesitation, not the normal deep breath in and deep breath out. Although the car FEELS fine. I make a point to stay out of boost until the engine is up to temp, but even staying out of boost I normally hear the intake/BPV sucking/blowing air respectively. Once the engine is warm, and I go into boost, they sound normal and I'm boosting fine. I don't know if at this point is has to do with my stock spark plugs and my power level or whether my intake is in a dire need of a good cleaning or if the BPV spring is failing or what.
My apologies if this is something stupid and obvious, but I'd rather be safe than sorry. Just thought it was alarmingly different in sound and I've been at this same power level for over a year. Last year's change in seasons I did not have the same issue.
. . .