RS7 Fuel System Issues: Common Fixes & Solutions

Had a very similar situation with my 2015 RS6. Started with rough idling and progressed to serious performance issues. After checking various fuel injection components, my workshop found the high pressure pump was failing, causing inconsistent fuel delivery and engine misfires. The car sensors were throwing multiple codes related to fuel pressure, which initially made us think it was just the fuel regulator. However, the complete diagnostic revealed the bigger issue with the pump. The fix involved: Full diagnostic scan, Pressure testing of the fuel system, Replacement of the high pressure pump, System reprogramming, Extended testing to ensure proper fuel delivery Total cost came to 1510 Euro including parts and labor. Since the repair, the engine has been running smoothly with no more rough idling or power loss issues. Before suggesting specific solutions for your case, could you share: Current mileage on your RS7? When did these symptoms first appear? Have you noticed any fuel consumption changes? Any recent maintenance work done? Are you getting specific error codes? This information would help determine if your issue matches what I experienced with my RS6.

My RS7 has 43250KM and had its last service 3 months ago. The car sensors readings definitely sound similar to your experience. Since you mentioned high pressure pump failure, I am wondering if my rough idling could also be caused by this. The engine misfire and performance issues match exactly what you described. I did get error codes P0087 and P0191, both related to fuel rail pressure. The check engine light started flashing intermittently before staying on permanently last week. Based on your repair costs, I should probably budget around 1500 Euro for the fix. Would you recommend getting the fuel pressure tested first before replacing any parts? The symptoms seem to align perfectly with your case.

After our last exchange about the fuel system issues, I can definitely confirm that your symptoms match my RS7 experience almost exactly. When I got those same error codes (P0087 and P0191), the fuel pressure test was absolutely crucial in confirming the high pressure pump failure. The rough idling and engine misfire patterns youre describing are textbook signs of inconsistent fuel delivery. The check engine light behavior, going from intermittent to constant, followed the exact same progression in my case before the pump completely failed. Regarding your question about testing: Yes, absolutely get a proper fuel pressure test done first. When my high pressure pump was failing, the test showed pressure dropping well below spec during idle, which explained the rough idling and power loss. Getting this diagnostic data helped avoid replacing parts unnecessarily. Looking at your mileage (43250KM), its actually quite similar to when my pump failed (around 45000KM). The repair cost estimate of 1500 Euro is realistic based on current parts prices, though labor rates might vary. Quick tip from my experience: while they are servicing the high pressure pump, have them check the low pressure fuel system components too. In my case, we found a partially clogged fuel filter that could have eventually caused similar issues.

Thanks for all the detailed feedback on the fuel system problems. The similarities between our cases are really helpful, same error codes, similar mileage, and identical symptoms with the rough idling and performance issues. Based on your experience, I will definitely get the fuel pressure testing done first before replacing anything. The car maintenance history at 43250KM matches closely with when your pump failed, so that makes sense as the likely culprit affecting fuel efficiency. I will also take your advice about checking the entire fuel injection system while they are working on it. No point having to deal with a clogged filter issue later when they can inspect everything during the same service. I will schedule the pressure testing this week and set aside around 1500 Euro for the potential repairs. The fact that your car has been running perfectly since the fix gives me confidence this is the right approach to resolve these fuel system problems. Will update once I get the test results and confirm if its indeed the high pressure pump causing all these issues with the rough idling and engine performance.