VW Scirocco PCV Issues: Smoke and Power Loss Fix

I had a very similar issue with my 2014 Golf GTI which presented the same symptoms you described, reduced power, check engine light, and exhaust smoke. After noticing increased engine oil consumption, I discovered it was indeed a faulty PCV valve causing crankcase ventilation problems. The symptoms pointed to a malfunction in the ventilation system, which was allowing oil vapor to enter places it shouldnt, causing those emissions issues you mentioned. My workshop diagnosed a significant leak in the PCV system, requiring a complete valve replacement along with some related seals. The total repair cost came to 360€, which included parts and labor. Since the fix, the engine has been running smoothly with no more smoke or power loss issues. To prevent future problems, regular oil changes and keeping the PCV system clean are crucial. However, before suggesting more specific maintenance tips, could you share: Current mileage on your Scirocco, Type of oil being used, Service history, particularly recent oil changes, Any other unusual sounds or symptoms This information would help determine if your case matches what I experienced and allow for more targeted advice.

I recently had the oil changed at 12614km during regular service. Running fully synthetic oil as recommended by manufacturer. When I first noticed smoke and ventilation malfunction, I checked the oil level which was normal, but the crankcase seems to be building excessive pressure. No unusual sounds besides a slight whistling during acceleration. The PCV issue seems very similar to what you experienced, did your repair also include cleaning the entire ventilation system or just replacing the valve?

Thanks for the additional details. Yes, my repair on the Golf GTI involved a complete system service, not just a valve replacement. The workshop performed a thorough cleaning of the entire ventilation system since oil residue can accumulate in the lines, causing further maintenance issues down the line. The whistling sound you mention is quite telling, I had the exact same symptom. Its typically a clear indicator of a leak in the PCV system, often caused by a cracked valve or deteriorated seals that cant handle the crankcase pressure properly. The good news is your regular oil changes and proper oil type usage should have minimized any potential engine damage. However, with these symptoms persisting despite proper maintenance, its crucial to address the ventilation malfunction soon to prevent more severe emissions problems. In my case, the complete service included: PCV valve replacement, Cleaning of all ventilation lines, Replacement of associated gaskets, System pressure test The thorough approach resolved all symptoms, including the whistling noise and smoke issues. Based on current parts costs, you should expect a similar repair cost to what I paid, assuming no additional complications are found during the service. Would be interested to hear if the pressure build-up youre experiencing fluctuates with engine temperature?

Thank you for the follow-up information about the ventilation system service. The pressure build-up does seem to vary with engine temperature, its notably worse when the engine is fully warmed up. Just scheduled an appointment with my regular workshop for next week to have them inspect the PCV system and clean the entire ventilation setup. Given the similar symptoms to your case, especially that distinct whistling and increased crankcase pressure, Im fairly confident were looking at the same issue. Really hoping its just the valve and basic system cleaning needed rather than any additional emissions components. Will update once I get the final diagnosis and repair completed. At least its somewhat reassuring to know this is a relatively straightforward fix based on your experience.