Audi Q2 Turbo Issues: Whistling and Power Loss Alert

Having dealt with almost identical symptoms on my 2018 Audi Q3 diesel last summer, I can share my repair experience. The check engine light and performance issues you describe match my situation perfectly. My initial symptoms also included power loss and that characteristic whistling noise during acceleration. After proper diagnosis, the workshop identified a defective wastegate valve on the turbocharger as the root cause. The boost pressure was inconsistent, leading to the performance issues you mentioned. The diagnostic process involved: 1. Computer scan of error codes 2. Boost pressure testing under load 3. Physical inspection of the turbocharger assembly 4. Checking all intercooler connections and hoses The total repair cost was 860 Euro in my case, including parts and labor. There were no effective temporary fixes, the wastegate needed proper replacement to resolve the issues. To provide more specific advice for your Q2: What mileage is currently on your vehicle? Have you noticed any blue smoke from the exhaust? Does the whistling sound occur at specific RPM ranges? Have you had any recent work done on the turbo system? This information would help determine if your issue matches what I experienced or if it might be something different in the boost pressure system.

Latest service was at 135000 KM about 2 months ago, and current mileage is 137192 KM. No blue smoke issues in my case. The whistling sound starts around 2000 RPM and gets louder with acceleration. Turbo system has not had any previous work done. The boost control and turbo lag symptoms seem a bit different from your Q3 experience. My whistling is loudest at mid-range RPM whereas yours seemed consistent across all ranges. The stalling at idle also suggests it might be a different issue with the turbocharger system. Good point about checking intercooler connections first. Will have the workshop inspect those before jumping to wastegate replacement. That 860 Euro repair cost gives me a helpful reference point for budgeting.

The symptoms you describe do sound different from my Q3 case, especially the RPM-specific whistling and idle stalling. After fixing my wastegate issue, I had a similar problem return 6 months later, but it turned out to be a cracked pressure sensor and loose intercooler hose, a much cheaper fix at around 280 Euro. The mid-range RPM whistle often points to boost leaks rather than wastegate failure. Given your mileage is similar to when my sensor failed, I recommend having the workshop specifically check: 1. All boost pressure sensors 2. Intercooler connections and clamps 3. Turbocharger seals and mountings The stalling at idle wasn't present in my wastegate case, which makes me suspect you might have a combination of issues. The check engine light codes should help pinpoint if its boost-related or something else in the turbocharger system. The good news is that if its just sensors and hoses, you are looking at a much lower repair cost than a full wastegate replacement. Worth getting a proper diagnosis rather than assuming the worst case scenario. Would you mind sharing the specific error codes when you get them? That would help confirm if your issue matches my second repair experience rather than the more expensive first one.

Thanks for the suggestions about checking the boost pressure sensors and intercooler connections first. I will definitely have the workshop start there rather than assuming a full wastegate repair is needed. Unfortunately I dont have the error codes yet, the earliest workshop appointment I could get is next week. Will make sure to request the full diagnostic report and error codes. The fact that your second repair with the cracked pressure sensor had similar symptoms but cost significantly less at 280 Euro gives me hope this might be a simpler fix. The turbo lag and boost control issues still concern me, especially since they happen most noticeably around 2000 RPM. But you make a good point that the idle stalling makes this seem different from a pure wastegate problem. I will update once I have the diagnostic results. If it turns out to be just boost leaks or a bad sensor that would be ideal. The full intercooler and sensor inspection seems like the smartest first step before replacing any major components.