Audi Q2 Diesel Glow Plug Issues Causing Multiple Alerts

I experienced very similar issues with my 2019 Audi Q3 diesel. As someone with moderate experience working on diesel engines, I recognized these symptoms immediately since they matched my situation perfectly. The constant preheating lamp and engine warning lights pointed to problems with the heating element system. During cold starts, my vehicle would struggle and occasionally stall. The excessive smoke during acceleration was particularly concerning. I took it to a workshop where they performed a diagnostic test. They found a loose cable connection at the glow plug control unit, which was causing intermittent electrical contact. The repair involved securing the connection properly and testing the entire glow plug system. Total cost was 95 Euro including diagnostic work. The fix completely resolved all symptoms, no more warning lights, proper cold start behavior, and normal exhaust. To provide more specific advice for your case, could you share: Current mileage on your Q2, Whether issues occur more during cold starts, If you notice any engine misfire or rough idling, When these symptoms first appeared, If any recent work was done on the engine This information would help determine if your situation matches what I encountered.

Thanks for the detailed insight. My current mileage is 151614 KM and last service was done at 145000 KM. The engine misfire mainly occurs during cold starts, making the diesel engine run quite rough for the first few minutes. Car maintenance records show no previous glow plug issues. The symptoms started about 2 weeks ago when temperatures dropped. I notice the heating element system takes longer than usual to warm up now. This definitely sounds similar to your experience with the loose connection. Will book a diagnostic test to confirm if its the same glow plug control unit problem.

Thanks for providing those details. The symptoms you describe match my Q3 situation even more closely than I initially thought. The cold weather correlation is particularly telling, as thats exactly when my glow plug system issues became most apparent. The mileage point is interesting, my problems started around 148000 KM, very close to your current reading. The heating element system showing delayed warmup combined with rough cold starts strongly suggests a glow plug control unit issue, just like in my case. After my repair, I learned that the control unit connections can gradually loosen due to engine vibration. The diagnostic test revealed that while the glow plugs themselves were fine, the control unit wasnt sending proper signals consistently. The engine light came on because the system detected these irregular signals. One additional tip from my experience: while they check the control unit, have them inspect all glow plug wiring. My mechanic found slight corrosion on one connector that could have caused problems later. Have you noticed if the smoke color during acceleration is black or blue? In my case, it was black smoke, which helped confirm it was a fuel combustion issue related to the glow plug system rather than an oil problem.

Thanks for that feedback about smoke color and the wiring inspection tip. Yes, the smoke is definitely black in my case, especially during morning startups. After hearing about your similar experience at almost the same mileage point, I feel more confident about the likely diagnosis. The vehicle stalling and engine misfire symptoms match exactly what you described. I just scheduled a diagnostic test for next week. The shop quoted 80 Euro for the initial diagnosis, which seems reasonable based on the price you mentioned. They said theyll thoroughly check the control unit connections and wiring harness while running the tests. Hopefully its just a loose connection like in your case rather than needing a full control unit replacement. Will update once I get the results back. Really appreciate you sharing your repair experience, it helped narrow down the probable cause and gave me a good idea of what to expect during the diagnostic process.