A5 Fuel Pump Problems: Diagnosis & Cost Guide

As someone with some hands-on experience working on cars, I had a very similar issue with my 2016 Audi A4. The symptoms you describe match what I experienced, engine stalling, rough idling, and increased fuel consumption. After taking it to my regular workshop, they diagnosed the problem through a comprehensive check of the fuel system. The issue turned out to be a faulty connection in the fuel pump wiring harness, rather than pump failure itself. The repair cost was 95 Euro, which included diagnostic time and fixing the cable connection. The mechanics checked: Fuel pressure readings, Electrical connections, Pump relay function, Error codes from the engine control unit Before you commit to replacing the entire fuel pump, which would be significantly more expensive, make sure your workshop thoroughly checks all electrical connections. Car performance issues like these can often be traced back to simple electrical faults. To help provide more specific advice, could you share: Current mileage on your A5, Any recent work done on the fuel system, Specific error codes from the check engine light, Whether the issues occur more during cold starts or when the engine is warm

Thanks for the detailed response. My A5 just had its service 2 weeks ago, and these issues started shortly after. The fuel system problems seem most noticeable during cold starts. My mechanic pulled error code P0087 which points to low fuel rail pressure. The car performance has definitely gotten worse, and fuel injector diagnostics might be needed too since the workshop mentioned that as a possibility. Having done some research, I am worried that a complete fuel pump replacement might cost upwards of 800 Euro if parts and labor are included.

Thanks for the additional details about your A5. Since you mentioned these issues started after the recent service, this triggers a red flag based on my A4 experience. Low fuel rail pressure (P0087) was exactly what I faced too. In my case, after the initial wiring fix I mentioned, the problem actually came back. The full fuel pump did end up needing replacement, but the root cause was traced to contaminated fuel that had damaged both the pump and injectors during routine service work. A few key points from my repair journey that might help you: The car performance issues were most severe during cold starts, just like yours, The auto repair shop found metal particles in the fuel filter, Complete fuel pump replacement with parts and labor came to 750 Euro, They also cleaned the fuel injectors as a preventive measure Before you proceed, have your workshop check: Fuel filter condition, Fuel tank for any contamination, All injector readings The fact that these problems started post-service suggests possible fuel system contamination. While pump failure is likely given the error code, addressing any contamination is crucial to prevent repeat issues.

Having my car back from the shop now, I wanted to update this thread to help others with similar fuel system problems. The issue was indeed related to the fuel pump and injectors, just as discussed. The car mechanics found significant contamination in the fuel system, likely from poor quality gas or debris that got in during the service. The workshop did a complete diagnostic check of the gasoline delivery system. They ended up replacing the fuel pump, cleaning all fuel injectors, and installing a new filter. Total cost came to 920 Euro including parts and labor. While expensive, the engine stalling issues are completely gone now and the car runs perfectly. For anyone facing similar symptoms, rough running, stalling at idle, and high fuel consumption, make sure your workshop checks for contamination before just replacing parts. The proper diagnostic steps saved me from having to deal with repeat issues. The complete fuel system inspection was worth the extra diagnostic time. Now I make sure to always fuel up at reputable stations and will be more vigilant about potential contamination during service work. Thanks everyone for the helpful advice!