Smoking Audi A3 with Multiple Issues Points to EGR Valve

Having dealt with a similar issue on my 2011 Audi A4. I can share some relevant experience. As someone with moderate automotive repair knowledge, the symptoms you describe strongly point to EGR valve problems, which matches my own experience. My car showed nearly identical issues, rough idle, significant power loss, and that characteristic hissing sound. The excessive fuel consumption and smoke from the exhaust are typical indicators of a failing EGR valve, often caused by carbon buildup blocking proper valve operation. The repair process at my workshop involved: Complete diagnostic scan, EGR valve removal and inspection, Cleaning of the surrounding intake system, Installation of new EGR valve, System reset and testing Total cost was 355 Euro, which included parts and labor. After the fix, fuel economy returned to normal and the rough running completely disappeared. Before proceeding further, could you share: Current mileage on your A3? When was the last time you had a major service? What type of fuel do you typically use? Any modifications to the engine? This information would help determine if there might be related issues requiring attention, as EGR problems can sometimes indicate other underlying vacuum leaks or catalytic converter issues.

Thanks for the detailed reply. My A3 just clocked 115002KM and had its last major service 6 months ago. All maintenance has been done by certified workshops using manufacturer specs. Your experience sounds similar, but my check engine light also flashes occasionally during acceleration. Could this indicate something more serious than just the EGR? Im concerned about potential catalytic converter damage from the rich fuel mixture. During the last emissions test, readings were borderline acceptable. The smoke from the exhaust has a slight blue tint, which seems different from typical exhaust gas recirculation issues. Planning to have it checked next week, but wanted to gather more insights from the community first.

Thanks for the additional details about your A3. That flashing check engine light during acceleration, combined with the blue-tinted smoke, definitely raises some red flags beyond just EGR valve issues. In my case with the similar A4, I initially thought it was just the EGR, but it turned out to be a combination of problems. The blue smoke likely indicates oil entering the combustion chamber, which wasnt present in my initial EGR problem. After further diagnosis, my shop found a failing turbo seal contributing to the issues. The total repair ended up including: EGR valve replacement, turbo seal replacement, vacuum line inspection and replacement of cracked hoses, full system diagnostic scan. The final cost came to about 890 Euro, but it resolved all symptoms including the rough idle and power loss. The flashing check engine light in your case could indeed point to catalyst-damaging misfires, which I also experienced before the complete fix. Given your borderline emissions test and the blue smoke, I strongly recommend having both the EGR system and turbo checked. The symptoms overlap significantly, and addressing just one might not solve the complete problem. Would definitely monitor oil consumption closely until you get it checked. Has your oil level been dropping more quickly than usual?

Thanks for the feedback. The oil consumption has definitely increased, Im now adding about 1L every 1000km, which is way more than normal. Your experience with the turbo issues makes a lot of sense given my symptoms. The rough idle and power loss match what you described, and the vacuum leak symptoms align with what Im experiencing. Im going to have them check both the EGR valve and the turbo seals during next weeks appointment. My main concern is passing the next emissions test, especially given the borderline results last time. The shop quoted me 950 Euro for a complete diagnosis and potential EGR valve replacement. Based on your experience, I should probably budget for additional repairs if the turbo seals need work too. Will update the forum once I get the final diagnosis and repair completed, hopefully it helps others with similar issues troubleshoot their cars.