VW Transporter Smoking: PCV Valve Symptoms Alert

Had almost the exact same malfunction on my 2011 VW Caddy last winter. Having some experience with basic maintenance and repairs, I first noticed similar symptoms, rough idle, decreased power, and exhaust smoke. The PCV valve and crankcase ventilation system were indeed the root cause. After the initial symptoms, the engine started running even more erratically at idle. The workshop confirmed the diagnosis through a pressure test of the ventilation system. The repair involved: Complete PCV valve replacement, New ventilation hoses, System cleaning, Labor costs Total cost was 360€, which included parts and labor. The repair took about 3 hours, and the symptoms disappeared completely after fixing it. Before giving more specific advice though, could you share: Current mileage on your Transporter, Engine size and type, Any recent maintenance history, Whether the smoke is white, blue, or gray, If the rough idle happens more when the engine is cold or warm This information would help determine if your case is similar and whether there might be additional issues to look out for.

Thanks for sharing your experience. My Transporter just had its annual service last month at 34318km. The smoke appears blue-grayish and the rough idle is most noticeable when the engine is warm. The emissions and engine performance issues started right after a period of heavy rain, which makes me think moisture might have affected the ventilation system. This matches what you described about the PCV valve failure. A repair cost of 360€ sounds reasonable if it resolves all these symptoms. Did you notice any leak from the valve before replacing it?

Thanks for those details. The blue-grayish smoke and timing after heavy rain matches exactly what I experienced with my Caddy. There was a visible oil leak around the PCV valve housing which I only noticed after specifically checking the area. The moisture from the rain likely accelerated the deterioration of the valve seals. The symptoms occurring more when warm also points strongly to PCV issues, as the ventilation system operates under higher pressure at operating temperature. In my case, the blue smoke was caused by oil being pulled through the failing valve into the intake system. The workshop found small traces of oil residue in the intake manifold due to the faulty ventilation system. The cleanup of these deposits was included in my quoted repair cost. Given your mileage and the recent rain exposure, you're likely facing a very similar scenario. One additional tip, make sure they check the intake manifold thoroughly for oil contamination during the repair. A proper cleaning prevents future performance issues and ensures the new PCV system works correctly. The 360€ repair completely resolved the emissions issues and restored normal engine operation. No related problems have occurred in the year since the fix.

My Transporter has 34318km on the clock and it's a 2.0L diesel. The smoke looks blue-grayish and gets worse when the engine is warm. Thanks for mentioning about checking for oil leaks, I just looked around the PCV area and noticed some oily residue, which seems to confirm your diagnosis. The timing with the heavy rain and the similar symptoms are quite convincing. Given the reasonable repair cost you quoted at 360€ and the fact it solved all issues, I think I will go ahead and book it in for the repair. Will make sure to ask them about checking and cleaning the intake manifold as well. Since the valve malfunction seems to be causing oil to enter places it should not be, I want to get this fixed before it creates more serious problems. I appreciate you sharing your maintenance experience, it has helped me understand what I am dealing with and what to expect from the repair process. I will update once I get the ventilation system repaired and confirm if it resolves the rough idle and smoke issues.