VW Up Power Loss & Black Smoke, PCV Valve Alert

Had similar symptoms with my 2016 VW Polo TSI, black smoke during acceleration, reduced power, and malfunction indicator. Crankcase ventilation system was indeed the culprit, causing excessive emissions and poor idle. The repair involved replacing the PCV valve assembly and cleaning the intake manifold which had oil residue buildup. The maintenance was necessary since a faulty PCV system can lead to serious engine damage if left unchecked. Oil contamination was starting to affect other engine components. The smoke occurs because when crankcase ventilation fails, engine oil vapors enter the combustion chamber instead of being properly recirculated. This creates that characteristic black smoke under load. Main warning signs that confirmed the diagnosis: Rough idle at stop lights, Oil residue inside intake piping, Whistling noise from engine bay, Failed emissions readings While not a major repair if caught early, ignoring these symptoms can lead to increased oil consumption and potential turbocharger issues. The repair resolved all performance issues and the smoke disappeared completely. A qualified workshop with VW diagnostic equipment should be able to confirm if your symptoms match PCV failure through proper testing.

Thanks for sharing your experience. That PCV valve issue sounds exactly like what I am dealing with. The symptoms match perfectly, especially that rough idle and whistling noise. Quick question, do you remember roughly how much the valve replacement and cleaning service cost you? Also curious if you had any similar maintenance issues pop up since getting it fixed? Just want to budget properly and make sure I get the repair done before it causes more serious engine trouble. The excessive emissions and poor performance are definitely concerning.

Since getting the crankcase ventilation valve replaced last year, my Polo has been running perfectly, no more smoke, no performance issues, and the engine idles smoothly. The total repair came to 360€, which included the new valve assembly, intake cleaning, and labor. The fix completely resolved the oil leak and emissions problems. Regular maintenance checks show no unusual oil consumption or residue buildup like before. The whistling noise and rough running disappeared immediately after the repair. Important to note that catching this early prevented damage to other components. A failing valve can lead to serious engine problems if left too long. Getting it fixed was definitely worth the cost to protect the engine and restore proper performance. The repair shop did a thorough job cleaning all affected parts while replacing the valve. No related issues have come up in the 12 months since the maintenance was done. The crankcase pressure is now properly regulated as it should be.

Thanks everyone for the helpful replies. Finally got my Up fixed last week after dealing with that annoying smoke and power loss. The mechanic confirmed it was indeed the PCV valve system causing all the trouble. Ended up paying 420€ total, a bit more than expected but they did a complete job replacing the valve and cleaning out all the oil residue from the intake. Found some serious gunk buildup in there which explained the poor performance. The difference in how the car runs now is like night and day. No more black smoke under acceleration, engine idles perfectly, and that annoying whistling sound is completely gone. Power is back to normal and the malfunction light cleared up right away. Good thing I caught it when I did, mechanic showed me how the old valve was completely gunked up. Could have caused some real engine damage if left unfixed. Lesson learned about not ignoring those early warning signs when they first appeared.