Q3 Fuel System Failure Symptoms & Repair Guide

Had identical issues with my 2018 Q5 last month. The symptoms match classic fuel delivery problems. The engine stalling at idle and rough running points to inconsistent gasoline delivery through the system. Initial automotive diagnosis revealed failing fuel injectors, but the real culprit was a loose wiring connection at the fuel pump assembly. The connector had corroded and lost proper contact, causing erratic fuel pressure. This made the engine stall out of nowhere and struggle to maintain proper running conditions. The fix required removing the fuel pump assembly to access and replace the damaged connector. While not a major repair compared to replacing the entire fuel pump, the labor is significant since the fuel tank needs to be lowered. Key points for your situation: Get fuel pressure tested before replacing parts, Have the wiring connectors inspected for corrosion, Request testing of the fuel injectors, Ensure computer diagnostic codes are properly read The intermittent nature of these symptoms often leads to misdiagnosis. A proper automotive diagnosis should include both electronic and mechanical testing of the entire fuel system.

Thanks for sharing your experience! My Audi Q3 experienced very similar issues with engine stalling and poor starting. The fuel pump turned out to be the main problem, just as you described. The symptoms matched exactly, rough running, inconsistent performance, and high fuel consumption. Did you remember roughly how much the repair cost in the end? Also wondering if youve had any other fuel system problems since getting it fixed? My car has been running great after the repair but always good to know what to watch out for with these fuel delivery issues.

After getting the fuel pump connection fixed, my Q5 has been running perfectly with no more engine stalling or fuel system problems. The final repair cost was surprisingly reasonable at 95 Euro, which covered fixing the corroded wiring connector at the fuel pump assembly. Much cheaper than replacing the entire fuel pump unit. The automotive diagnosis was spot on, it was just that damaged connector causing all those fuel delivery issues. The car mechanics did a thorough check of the fuel injectors and pressure testing while they were at it, confirming everything else was working properly. For preventive maintenance, I now regularly check for any signs of rough running or inconsistent idle. Early detection of fuel system problems can help avoid more serious issues down the road. But honestly, since that repair, the engine runs smoothly and fuel consumption is back to normal. Just keep an eye on your fuel pressure and listen for any unusual sounds from the fuel pump area. A properly functioning fuel system should be virtually silent during operation.

Thanks for the helpful advice. Just wanted to share how my repair experience turned out. After getting multiple opinions, I took it to a new auto repair shop that specializes in fuel system diagnostics. The car mechanics found the fuel pump was indeed failing, but also discovered corroded wiring similar to what others mentioned. The total repair came to 780 Euro including parts and labor. They had to drop the fuel tank to access everything properly. The difference in car performance is amazing, no more engine stalling or rough running. Fuel consumption is back to normal and it starts perfectly every time. The shop did a great job with the automotive diagnosis, testing the entire fuel delivery system before and after the repair. For anyone facing similar issues, I learned its worth getting a proper diagnosis rather than just replacing parts. The comprehensive testing helped identify all the problems at once, saving money in the long run. Just hit 1000km since the repair with zero issues. Really glad I got this sorted before it left me stranded somewhere. Thanks again for steering me in the right direction with this!