VW Crafter PCV Issues Causing Power Loss and Smoke

Had the exact same symptoms on my 2008 Volkswagen LT35 diesel last winter. Based on my experience with several diesel engines, this definitely sounds like a PCV system issue causing excess emissions. The symptoms match perfectly, rough idle, power loss, and oil-heavy smoke under load. My engine was basically inhaling its own oil mist due to the failed crankcase ventilation. Took it to my regular workshop after attempting basic diagnostics. They confirmed a completely clogged PCV valve and found an additional small vacuum leak in the ventilation lines. The full repair included: New PCV valve assembly, Replacement of degraded ventilation hoses, System cleaning, New gaskets Total cost was 360€ for parts and labor. Engine ran like new afterwards, no more smoke, proper idle, and power restored. The repair eliminated the emissions problems completely. To help diagnose your specific case, could you share: Current mileage, Any engine oil consumption changes, Whether the smoke is black or blue-gray, If you notice any unusual engine sounds at idle These details would help determine if your symptoms truly match the PCV malfunction I experienced.

Last service was done at 168000KM and I am seeing increased oil consumption since then. The smoke is definitely blue-gray and there is a slight rattling at idle that was not there before. The ventilation symptoms you described match my situation exactly. Seeing the maintenance costs broken down is really helpful. My regular maintenance never included a PCV check, so a clogged valve makes sense with the high mileage. My main concern was the repair cost ballooning if there were other emissions-related issues, but 360€ seems reasonable for fixing the crankcase pressure problems. Will get it checked at a shop this week before the leak gets worse. Thanks for confirming this is likely just the PCV system. Very helpful to hear from someone who resolved similar symptoms successfully.

Good to hear you are getting it checked soon. The blue-gray smoke and rattling you described matches my PCV valve failure symptoms exactly. The increased oil consumption after your last service also points clearly to crankcase ventilation issues, my oil levels were dropping faster before the repair too. For reference, my valve was completely blocked when they removed it, causing dangerous crankcase pressure. The maintenance technician showed me how the old valve was stuck closed from oil deposits. A blocked PCV system will definitely cause those emissions problems you are seeing. Just keep in mind that with these engines, a bad valve can sometimes damage related components if left too long. In my case, we caught it early enough that only the valve itself and some hoses needed replacement. The full repair took about 3 hours of labor. Let us know what the workshop finds. The symptoms are textbook for PCV failure, but having them verify the exact cause is important for proper maintenance. That rattling noise should clear up once the ventilation system is working correctly again.

Update: Got the van checked today and you were spot on. The PCV valve was completely clogged just like yours was. Workshop confirmed the ventilation system malfunction was causing all my symptoms. Total repair came to 380€ including a few extra seals they recommended replacing. The smoke issue is completely gone now and that annoying rattle at idle has disappeared. Engine feels much stronger and the oil consumption has normalized. Really glad I caught this maintenance issue before it caused more serious problems with the crankcase pressure. The repair took about 3.5 hours, pretty close to what you mentioned. They showed me the old valve and it was totally blocked with oil residue. Makes sense why the leak was getting worse during acceleration. Thanks again for helping identify the problem. Having your repair experience as reference made me confident enough to get it fixed before any major damage occurred.