Giulia's Turbo Boost Sensor Causing Multiple Issues

Had identical symptoms on my 2016 Alfa Romeo Stelvio diesel last month. The whistling sound combined with power loss strongly indicated a boost leak, which was confirmed when the engine light came on. The boost sensor was actually fine, turned out there was a loose connection at the intake manifold, plus a small crack in one of the intercooler pipes. These issues caused inconsistent turbo boost readings, making the engine run rich and struggle with power delivery. This type of boost leak is a known weak point on these engines. The repair involved replacing the damaged pipe and properly securing all intake manifold connections. While not a major mechanical issue, it needed immediate attention to prevent further performance degradation and potential damage to other components. The symptoms match your situation perfectly, whistling noise, rough acceleration, increased fuel consumption, and power loss. Would suggest getting the entire boost system pressure tested rather than just replacing the sensor straight away. A proper diagnosis will save both time and parts.

Thanks for sharing your experience. Those infamous boost leaks are really tricky to diagnose. Your symptoms match what my Giulia went through last year, the check engine light, power issues, and that distinct whistling from the turbo system. Did the air intake and intercooler pipe replacement fix everything for good? Would be helpful to know what you paid for the repair job. Just wondering since I am dealing with occasional stuttering again, though not as severe as the first time.

After my previous post, I took the car back to the shop since the issues came back. Unlike my first repair which involved the intake system, this time it actually was a faulty boost sensor causing the problems. The check engine light triggered again, but the mechanic quickly identified that the boost sensor had a damaged wire connection. The repair was straightforward, they fixed the defective cable connection to the boost pressure sensor for 95 Euro. Since that repair, the turbo boost and engine performance have been perfect. No more power loss or stuttering like you described. This shows how similar symptoms can have different root causes in these turbo systems. While my first issue was related to the air intake and boost leak, the second time it was purely an electrical problem with the sensor. Getting proper diagnostics is crucial since boost-related issues can be tricky to pinpoint.

Thanks everyone for the helpful replies. I finally took my car to a reputable shop that specializes in turbo systems. The mechanic found that the check engine light was indeed triggered by a failing boost sensor, just like some of you experienced. The total repair came to 280 Euro including diagnostics and parts. They also discovered and fixed a small crack in the intake manifold while they were at it. After the repair, the turbo boost is working perfectly again, no more whistling sounds or power issues during acceleration. What a relief to have this sorted properly. The car runs better than ever and fuel consumption is back to normal. Definitely worth getting it checked by specialists who know what they're doing with these setups rather than trying quick fixes.