VW Nivus Smoking Exhaust Points to PCV Valve Failure

Had a similar issue on my 2021 VW T-Cross with the 1.0 TSI engine. After some basic troubleshooting, the symptoms matched yours, check engine light, reduced power, and smoke from the exhaust, especially during acceleration. The PCV valve was indeed the problem, causing excessive crankcase pressure and oil consumption. This led to unstable idle and those smoke emissions you mentioned. The repair involved replacing the complete valve assembly and cleaning the intake manifold. Total cost was 360€, including parts and labor. The workshop completed the job in about 3 hours. Since the fix, the engine runs smoothly with no smoke or power issues. To better assist, could you share: Engine size and type, Current mileage, Color of the exhaust smoke, Any unusual engine sounds at idle, When the symptoms first appeared These details would help confirm if your issue matches what I experienced. A faulty PCV system can lead to more serious problems if left unchecked, so getting it diagnosed properly is important.

Thanks for sharing your experience. My last service was 2 weeks ago, but this malfunction started showing right after, at 100059km. The smoke is grayish-white and appears consistently during acceleration. No odd sounds at idle, but there is a noticeable power lag when pressing the gas pedal. Your repair experience is helpful. My emissions issue does sound similar, and the crankcase ventilation symptoms match exactly what Im seeing. Did you notice any oil leak around the valve area before the repair? This could help me confirm if Im dealing with the same problem before taking it to a mechanic.

Thanks for the additional details. Yes, when I had the PCV valve issue on my T-Cross, there was a small oil leak around the valve housing. The oil residue was most noticeable on the top side of the engine cover, which is a classic sign of PCV failure. The grayish-white smoke and power lag you describe match my experience exactly. The smoke during acceleration was caused by oil being pulled into the intake due to the faulty valve. When the PCV system fails, it cant properly regulate crankcase pressure, leading to these symptoms. At 100000km, this is fairly common timing for PCV issues. My repair was done at 95000km, and the mechanic mentioned these valves typically need attention around this mileage. One thing to check, does your oil consumption seem higher than normal? In my case, I was adding about 1L between services. The leak and excess consumption stopped completely after the PCV replacement. The idle behavior is interesting, mine had a rough idle, but since yours is smooth, the valve might be in an earlier stage of failure. Getting it checked soon would prevent any increased oil consumption or potential catalytic converter damage.

Thank you everyone for the input. After checking my engine cover, I found a small amount of oil residue just like you described. Given the similar symptoms, especially the emissions and crankcase pressure issues, Im fairly confident its the PCV valve. The timing makes sense too since Im right at 100000km. Ill get it checked this week to prevent any additional problems. The stable idle is somewhat reassuring, but the power loss and smoke during acceleration definitely need addressing. Ill monitor the oil level closely until the repair. Thanks for the maintenance tips and sharing your repair experience. The 360€ cost estimate helps with planning. Hopefully a valve replacement will resolve these symptoms like it did in your case. Anyone know a good way to clean the intake manifold after the repair? Id like to ensure any oil residue is properly cleared out once the new PCV is installed.