VW Tiguan Diesel: PCV Issues Causing Power Loss

Having dealt with almost identical symptoms on my 2010 VW Touareg diesel, I understand your concern. The rough idle and power loss combined with smoke are classic signs of a failing PCV system and crankcase ventilation issues. After noticing similar problems, I took my Touareg to a certified workshop where they diagnosed a defective crankcase ventilation system. The symptoms match yours exactly, the engine would run rough at idle and lose power during acceleration, with visible exhaust smoke. The total repair came to 360€, which included replacing the PCV valve and related components. The fix resolved all symptoms, and the engine returned to normal operation. Most importantly, it prevented potential long-term damage to the engine. This is definitely something that needs prompt attention, as a faulty PCV system can lead to: Oil consumption issues, Vacuum leaks, Increased internal engine pressure, Potential turbo complications Before offering more specific advice, could you share: Current mileage on your Tiguan, Whether you notice any oil consumption, If there are any specific error codes showing, When the symptoms first appeared This information would help determine if your case is similar and whether additional components might need inspection.

Last service was 3 months ago, and I want to thank you for the detailed response. The error codes are P0171 and P2279, and the symptoms started about 2 weeks ago. Oil consumption seems normal, no noticeable loss between checks. The idle gets particularly rough after the engine warms up, and the crankcase ventilation issues seem worse during cold mornings. The emissions smoke has a slightly bluish tint. The PCV valve makes a slight rattling noise, which I noticed while checking the engine bay. Given the similar repair cost you mentioned, this definitely seems worth addressing before it causes more extensive problems.

Thanks for the additional details. Those error codes (P0171 and P2279) along with the symptoms you described match exactly what I experienced with my Touareg before the PCV repair. The rattling noise from the valve is a definitive sign the system needs attention. The bluish smoke and rough warm idle further confirm the crankcase ventilation issues. My vehicle showed the same pattern, particularly with the cold morning symptoms being more pronounced. After my PCV valve replacement, I noticed: Smoke completely cleared up within 2-3 drives, Power returned to normal, Idle smoothed out significantly, Engine ran noticeably quieter The fact your last maintenance was recent but didnt catch this suggests the PCV failure progressed rapidly, which is common with these units. The good news is addressing this now, before winter maintenance needs kick in, will prevent oil contamination and potential turbo wear. The repair is straightforward and the 360€ I mentioned included labor. Some shops might charge less depending on their rates, but the important thing is using proper OEM parts for the ventilation system to prevent future issues.

I appreciate all this information about the PCV valve repair and outcomes. Based on what you shared about the repair cost and the visible improvements after fixing it, I will schedule a workshop visit this week. My particular symptoms with the smoke, rough idle, and ventilation issues align perfectly with what you experienced. The cold morning problems and error codes matching your case make me confident about the diagnosis. Since the maintenance costs seem reasonable at around 360€ and the repair prevents more serious engine damage, moving forward with the fix makes sense. My main relief is knowing this is a common issue with a straightforward solution. The blue smoke and valve noise had me worried about more severe problems. Now I can get this addressed before the crankcase ventilation failure causes any lasting engine damage. I will make sure to request OEM parts as suggested to avoid future complications.