Q5 EGR Issues, Multiple Symptoms & Performance Drops

I had similar issues with my 2019 Audi Q3 last year and have some experience with EGR valve problems. The symptoms you describe match what I encountered, especially the power loss and rough idle. After noticing these issues, I took my Q3 to a workshop where they diagnosed a faulty EGR valve. The valve was stuck in a partially open position, causing incomplete combustion and the emissions-related problems. The repair included cleaning the EGR system and replacing the valve itself, costing 355 Euro in total. The fix resolved all issues: Restored normal power delivery, Eliminated the rough idle, Fixed the excessive smoke, Solved the jerking during acceleration, Removed the hissing sound, Normalized fuel consumption, Cleared the check engine light Before suggesting specific solutions, could you share: Current mileage on your Q5? Any recent maintenance history? Have you had any vacuum leak tests done? Did you scan for specific error codes? This information would help determine if your situation matches my experience with the EGR valve replacement or if there might be other underlying issues with the catalytic converter or vacuum system.

Thanks for sharing your Q3 experience. My Q5 is at 91383 KM and had its last service 3 months ago. Following your questions, I did get a vacuum leak test done and it came back negative. The error codes point to both emissions and fuel mixture issues. I appreciate the detailed repair cost breakdown. My mechanic mentioned potential problems with either the catalytic converter or vacuum leak, but the symptoms match your EGR valve experience closely. The rough idle and power loss are particularly concerning since they started suddenly. Would you recommend getting a second opinion before proceeding with the EGR valve replacement? The automotive repair shop I usually go to quoted 450 Euro for the complete job.

Thanks for the additional details about your Q5. Since your symptoms match what I experienced with my Q3, especially the rough idle and emissions-related problems, I still lean towards the EGR valve being the culprit. The quoted 450 Euro for the repair actually seems reasonable, considering current parts prices. It is higher than what I paid, but prices have increased since my repair last year. However, given your recent service and the error codes showing both emissions and fuel mixture issues, I would suggest: 1. Request a thorough EGR system inspection for carbon buildup 2. Have them check the intake manifold while testing the EGR 3. Verify the connection between the valve and engine control unit The combination of rough idle, increased fuel consumption, and emission-related codes strongly suggests recirculation system problems. But with those specific error codes, its worth checking the entire emissions system, including the catalytic converter, before replacing parts. In my case, cleaning the EGR system first would have potentially reduced the total repair cost. The automotive repair technician later told me this could have prevented the valve failure in the first place. The quoted price should include cleaning and testing before replacement. Make sure this is part of their service plan.

Thanks for the advice. After considering your feedback, I decided to move forward with the repair but asked my mechanic to perform a complete EGR system inspection first, including checking for carbon buildup and testing connections. The diagnostic revealed heavy carbon deposits in the EGR system. The check engine light and rough idle issues were definitely linked to the faulty valve. Total repair cost came to 475 Euro, slightly more than initially quoted, but included a full system cleaning and new gaskets. After the repair: Vehicle emissions returned to normal, The rough idle completely disappeared, Power delivery is smooth again, No more excessive smoke, Fuel consumption back to standard For others facing similar diesel engine problems, I recommend getting the complete system checked rather than just replacing parts. The thorough cleaning made a noticeable difference in performance. I plan to have the EGR system cleaned during regular maintenance to prevent future issues. Thanks again for helping me avoid potentially bigger problems down the road.