A5 EGR Issues: Smoke, Poor Performance & Rough Idle Fix

Recently dealt with nearly identical EGR valve issues on my A3 with the 2.0 TFSI engine. The symptoms matched perfectly, rough idle, power loss, and that distinctive hissing noise during acceleration. The root cause was carbon buildup causing the EGR valve to stick partially open. This created a constant vacuum leak, leading to improper air-fuel mixture. The recirculation system was basically forcing exhaust gases back when it shouldn't. The repair required: Complete EGR valve removal and replacement, cleaning of the EGR passages, clearing fault codes, testing the new valve operation. This was a serious issue that needed immediate attention since it was damaging the catalytic converter due to improper combustion. Letting it go longer would have led to more extensive engine damage. Key things to watch for during repair: make sure they properly clean all connected passages, check if the EGR cooler is also affected, verify proper diagnostic testing after replacement, ensure they use OEM or high-quality parts. The fix resolved all symptoms completely, restored proper idle, eliminated smoke, and brought back normal power delivery. Just make sure to use a reputable shop that specializes in automotive repair, specifically with experience on these engines.

Thanks for sharing your experience. Dealing with similar vehicle emissions issues on my A5 right now. Really worried about getting ripped off, so its helpful to hear how your repair worked out. Did you remember roughly what the total repair cost came out to? Also curious if youve had any recurring problems with the EGR valve or vacuum leaks since getting it fixed? My current recirculation problems are causing me a lot of stress and Id like to avoid dealing with this again in the future.

The repair cost came to 355 Euro total when I had the defective EGR valve fixed last month. The price covered both parts and labor for a complete EGR valve replacement and system cleaning. Since having the automotive repair done, my diesel engine has been running perfectly with no more rough idle or emissions problems. The fix completely resolved all the prior issues, no more check engine light, normal power delivery restored, and fuel economy back to standard. Its been a relief not having to deal with those recirculation system problems anymore. The key was getting the entire EGR system properly cleaned along with installing the new valve. To avoid future EGR valve issues, regular maintenance and using quality fuel really helps prevent carbon buildup. Its now been several thousand kilometers of trouble-free driving with no recurring vacuum leaks or valve problems. The repair was worth every cent considering how much better the engine runs now.

After getting multiple recommendations, I finally took my A5 to a certified repair shop last week. The mechanic confirmed it was indeed the EGR valve causing all those issues. They did a complete system inspection and found heavy carbon deposits blocking proper recirculation. The total repair came to 420 Euro, which included: new OEM EGR valve, full system cleaning, diagnostic testing, labor costs. The results were immediate, no more smoke, hissing stopped completely, and the engine runs smooth again. Passed the emissions test easily afterwards. The fuel economy has improved significantly too. Looking back, I was right to be cautious about choosing a repair shop. The mechanic took time explaining everything and showed me the old valve with all its carbon buildup. For anyone facing similar issues, getting it fixed properly the first time is worth the investment. Really glad I didnt try any quick fixes or put it off any longer.