Crafter Diesel Intake Manifold Issues & Performance Drop

I dealt with nearly identical symptoms on a 2015 Transporter TDI last year. As someone with moderate experience working on diesel engines, the symptoms you describe instantly reminded me of my situation. The engine performance problems started similarly, jerky acceleration, increased fuel usage, and that distinctive hissing noise. The engine light eventually came on, indicating an airflow control issue. After diagnosis, it turned out the intake manifold flap control unit had failed completely. Took it to a workshop where they confirmed the flap control mechanism was stuck, disrupting proper airflow management. The entire intake manifold assembly needed replacement. Total cost was 465€ including parts and labor. Since the repair, engine performance returned to normal and fuel economy improved significantly. To provide more specific advice about your case, could you share: Have you had any diagnostic codes read? When did the symptoms first appear? Has the engine light activated? What is your current mileage? The intake manifold design is quite similar between these models, so your repair approach might be comparable. Just make sure to have a proper diagnosis done before proceeding with any repairs.

Thanks for sharing your experience. Last service was done 3 months ago at 75466KM. I just got the codes read and it shows P2015 along with reduced airflow codes. The hissing under load has gotten worse since my initial post. The engine light started flashing yesterday during highway driving. Based on your repair cost details, this seems like a manageable fix. My main concern was potential internal engine damage from running with compromised intake system performance. Good to hear your engine runs fine after the repair. Will schedule a workshop visit this week to have the intake manifold assembly checked. Did your workshop mention any preventive measures to avoid future intake flap failures?

Thanks for the follow-up. The P2015 code matches exactly what I experienced with the intake manifold flap failure on my Transporter. When my engine light started flashing during highway driving, I reduced speed immediately to prevent potential damage. The workshop actually mentioned a few key points about preventing future manifold flap control issues: 1. Regular oil changes are crucial as carbon buildup can affect flap movement 2. Using high-quality fuel helps minimize deposit formation in the intake system 3. Occasional high-rev driving helps keep the flaps moving freely My engine has been running perfectly for 25000km since the repair with no reduced power issues or warning lights. The workshop cleaned the entire intake system while replacing the manifold assembly, which probably helped prevent reoccurrence. Your mileage is similar to when my issue occurred. The flashing engine light suggests getting it fixed soon is important. Extended driving with faulty intake flaps can lead to increased stress on other engine components. The loud hissing noise you mentioned getting worse matches the progression I experienced, it became more noticeable just before the flap control failed completely.

Based on this thread, I can reply in the voice of: Appreciate the detailed preventive tips. The hissing noise has gotten even more pronounced today, so I made an urgent workshop appointment for tomorrow morning. Your experience with similar symptoms and the complete fix is reassuring. A quick update, noticed significantly reduced power output during my morning commute. Engine performance seems especially affected during cold starts, and the jerking during acceleration has become more pronounced. The flashing engine light and these worsening intake manifold flap symptoms convinced me not to delay repairs any longer. Will make sure to discuss the preventive measures with my mechanic, particularly about the high-rev driving and intake system cleaning. The airflow control issues are clearly affecting overall engine performance now. Good to know the repair solved all issues in your case, hoping for similar results with mine. Will update this thread after the workshop visit with the actual diagnosis and repair outcome. Thanks for all the helpful information about your experience with the manifold flap replacement.