VW Phaeton Diesel Power Loss & Stalling: Fuel Reg Issue

I had a similar situation with my 2013 VW Passat diesel about a year ago. Having some experience with diesel engines and automotive repair, the symptoms you describe match exactly what I encountered. The check engine light was persistent and the rough idling became worse over time. Initially, car sensors were indicating a fuel pressure issue, and after a comprehensive diagnosis, the workshop confirmed a defective high pressure pump. The repair involved: Complete fuel system diagnostic check, Replacement of the high pressure pump, Recalibration of fuel injection system, System bleeding and testing Total cost was 1510€ including parts and labor. The repair resolved all issues, no more stalling, power loss disappeared, and fuel efficiency returned to normal. Before suggesting specific solutions, could you provide: Current mileage, Service history details, Any recent fuel system maintenance, Specific error codes from check engine light, Whether you notice any unusual fuel consumption This information would help determine if your Phaeton is facing the same issue. Since our vehicles share similar fuel system architecture, knowing these details would enable more targeted advice.

Last service was completed at 17500km, so relatively recent. Got all the error codes from the workshop yesterday: P0087, Fuel Rail/System Pressure Too Low P0401, Exhaust Gas Recirculation Flow Insufficient P2291, Injector Control Pressure Too Low The fuel consumption has definitely increased by about 15% over the past month. Regarding the car maintenance history, this is the first major issue since purchase. Worth noting the rough idling gets especially bad after the engine warms up, which might help pinpoint the problem. The local workshop quoted 1900€ for a complete fuel injection system overhaul, which seems steep. Looking for second opinions before proceeding with such an expensive repair.

Thanks for those detailed error codes and symptoms. After successfully fixing my Passat with similar issues, I can suggest a more targeted approach that might save you money. Those error codes, especially P0087 and P2291, strongly indicate a fuel delivery problem, matching my experience exactly. The increased fuel consumption paired with rough idle after warmup mirrors what my car exhibited before the repair. Rather than a complete system overhaul, I would recommend: 1. High pressure fuel pump inspection and testing (likely the main culprit) 2. Fuel pressure sensor verification 3. Basic injector performance test In my case, replacing just the high pressure pump and its associated sensors resolved all three error codes, including the EGR flow issue. The engine misfire and poor fuel economy issues cleared up immediately. My repair was 1510€ versus your quoted 1900€ for a full system overhaul. Based on the matching symptoms and error codes, you might not need the complete overhaul. Consider getting a second quote focused specifically on the high pressure pump and associated components. Would be helpful to know if you have noticed any metallic sound when idling, as this could further confirm if your issue matches what I experienced with the fuel system.

Thanks for the thorough explanation about the error codes and repair costs. The metallic sound you mentioned is definitely present, especially during cold starts. Its a distinct ticking noise that seems to come from the front of the engine. After comparing repair quotes from three different workshops, I found one that will diagnose and potentially replace just the high pressure fuel pump for 1600€. They mentioned the rough idling and fuel efficiency issues should resolve once the pump is fixed, and they will verify the fuel injection system operation before and after the repair. Going to book the repair for next week and will make sure they perform the sensor verification you suggested. The targeted approach focusing on the pump rather than a complete system overhaul makes more sense given the symptoms match your experience so closely. Will update once the repair is completed to confirm if this resolved all the issues.