VW Touran Diesel: Power Loss and Smoking Exhaust Fix

Had the same issues on a 2011 VW Passat diesel. The crankcase ventilation malfunction caused similar symptoms, reduced power, smoke from exhaust, and engine warning light. The idle was notably rough and unstable. The ventilation system failure allowed oil vapor to enter places it shouldnt, causing the smoke and performance issues. The mechanic found that the PCV valve was completely clogged and the breather hose had deteriorated. This turned out to be a serious issue requiring immediate attention. Left unfixed, it can lead to increased engine wear, oil consumption, and emissions problems. The repair involved replacing the complete ventilation assembly and cleaning the intake manifold that had become contaminated. The symptoms you describe match exactly what happened with my Passat. Would strongly suggest getting it checked soon, as driving with a faulty crankcase ventilation can cause additional engine damage. Best to have a professional diagnose it properly since several components in the system could be at fault.

Thanks for sharing your experience with the PCV valve issue. Mine got fixed about 2 months ago and the smoke problem cleared up right away. The rough idle is completely gone too. I was wondering how much you ended up paying for the complete repair? My bill seemed a bit steep and Im curious if theres been any other issues popping up since your fix? These emissions-related repairs can sometimes reveal other problems.

The complete ventilation system repair on my Passat cost 360€, which included replacing the valve and cleaning the affected components. Since getting it fixed, the engine has been running smoothly with no additional issues or leaks. The maintenance really solved all the problems, no more smoke, rough idle, or check engine warnings. It was worth every cent considering how the crankcase ventilation malfunction could have caused more expensive engine damage if left unfixed. Just keep an eye on your oil levels during routine maintenance checks, but you shouldnt see any related problems now that its properly repaired. Getting the complete fix done in one go prevented any cascade of issues that sometimes happen when only partial repairs are made. Two years later and the ventilation system is still working perfectly.

Thanks for the advice. After your responses, I took my Touran to the mechanic last week. The inspection confirmed a faulty crankcase ventilation system causing the smoke and power issues. The total repair came to 420€, including parts and labor. The mechanic showed me the clogged valve and explained how it was affecting the emissions system. They also found a small leak in one of the connecting hoses that needed replacement. The whole job took about 4 hours. Now the engine runs perfectly, no more smoke from the exhaust and power is fully restored. The check engine light cleared up immediately after the repair. Really glad I got it sorted before it caused any serious engine damage.