Audi A6 Fuel Pump Woes: DIY Testing and Solutions

Having experienced similar fuel system issues with my 2003 Audi A4, I can relate to your situation. As someone with moderate automotive diagnosis experience, these symptoms definitely suggest fuel delivery problems. In my case, the rough running and stalling were actually caused by a loose wiring connection at the fuel pump. The cable connection had deteriorated over time, causing intermittent fuel pump operation. After proper diagnosis at a workshop, they found the faulty connection was creating similar symptoms to a failing pump. The repair was relatively straightforward, costing 95 Euro for labor and materials to repair the connection. This was much cheaper than replacing the entire fuel pump assembly. Before jumping to conclusions about pump failure, you might want to: 1. Check the fuel pressure using a gauge 2. Listen for the pump priming when turning the key 3. Inspect all visible fuel system connections 4. Get the specific error codes read and documented To provide more targeted advice, could you share: The engine size and type, Current mileage, Specific error codes stored, Whether the problem occurs more when the tank is low on fuel These details would help determine if your issue matches what I experienced with the wiring problem or if it might be something else in the fuel system.

Thanks for investigating my fuel delivery issue. Had my latest service at 71000 KM and currently at 73875 KM. The mechanics did a fuel pressure test which showed the fuel pump is operating below normal pressure levels. The distinctive whirring sound when turning the key is also much quieter than usual, further suggesting fuel pump failure. The engine stalling symptoms have gotten worse since posting. When idling, the engine now cuts out completely unless I maintain slight pressure on the accelerator. The fuel injectors were cleaned during my last service, so I am fairly confident the fuel pump needs replacement. Would appreciate guidance on expected labor hours and whether I should replace the fuel filter at the same time.

Based on your symptoms and test results, I can definitely confirm my earlier suspicion about fuel pump issues. In my A4, I was fortunate to only have a wiring problem, but your case shows clear signs of pump failure with the low pressure test results and that quieter priming sound. When my mechanic replaced the fuel pump on another A4, the job took about 3-4 hours labor. The pump assembly cost around 450 Euro, plus about 200 Euro for labor. Since access to the fuel pump requires dropping the fuel tank, absolutely replace the fuel filter while everything is apart, it only adds about 25 Euro to the total cost but saves future headaches. The below-normal pressure readings from your test match classic fuel pump failure symptoms. Your need to keep the accelerator pressed to prevent stalling is exactly what happens when the pump cant maintain proper fuel delivery at idle. A quick tip from my experience with auto repair: make sure they inspect the wiring harness and connectors during installation. Poor connections can cause premature pump failure, and you want to avoid repeating this repair. The increasing frequency of your stalling issues suggests getting this fixed soon before you risk getting stranded somewhere. When my pumps pressure dropped, it also led to catalytic converter issues from running too lean.

Thanks for the detailed breakdown of the fuel pump repair. This additional information really helps confirm my suspicions. Those pressure test readings definitely point to the pump being the culprit, especially combined with the quieter priming sound and constant stalling issues. The cost estimate sounds reasonable, 450 Euro for the pump plus 200 Euro labor is in line with what I expected for this kind of automotive diagnosis and repair. I agree that adding a new fuel filter for 25 Euro makes perfect sense while the tank is already dropped. No point saving a small amount now only to pay full labor costs again later. Given how quickly the car performance is degrading and the increased fuel consumption, I will schedule the repair for next week. The tip about checking the wiring harness during installation is particularly valuable, I will make sure to mention this to the mechanic to prevent any future issues. Will need to be extra careful driving until then since the stalling is getting worse. Finding myself having to ride the gas pedal constantly just to maintain idle, which cant be good for the engine or catalytic converter.