BMW N20 Turbo Whistling: Charge Air Sensor Alert

Had the exact same issue on my 2011 BMW 1 Series last month. The symptoms matched perfectly, reduced power, whistling noise, and CEL. Initially thought it was the turbo failing, which got me worried. Turned out the charge air temperature sensor connector was loose and partially melted. The wiring harness had some wear too. The sensor itself was actually fine, but the connection was the culprit. Wasn't a major repair, just needed new connectors and a harness repair. Not a serious issue if caught early, but ignoring it could lead to bigger problems with the turbo system. My car runs like new now, back to full power with no weird noises. Best to get it checked soon, these symptoms usually don't fix themselves. The whole diagnostic process was pretty straightforward for my mechanic. Just make sure they check the connections thoroughly before replacing parts.

Hey, glad you got that sorted out! Your symptoms did sound exactly like what I experienced. Been really curious, would you mind sharing what you ended up paying for the repair? Just trying to get an idea since I'm planning to take mine in soon. Also, has everything been running smoothly since the fix, or have you noticed anything else pop up? My car's been sitting in the driveway while I figure out what to do, and I'm just trying to avoid any surprise costs.

Hey again! Happy to give you an update. After taking it to the mechanic, they found the exact same problem, it was indeed the charge air temp sensor giving trouble. Got it fixed last month and it cost me 95 € to repair the faulty cable and plug connection. Pretty reasonable, I'd say, especially since I was worried it might be something more serious with the turbo! The car's been running absolutely perfect since the fix, no more whistling sounds, full power is back, and the check engine light hasn't shown its face again. Trust me, I know that feeling of leaving the car sitting there while trying to figure out the best move, but you shouldn't worry too much about this one. It's a pretty straightforward fix. I'm actually glad I didn't wait any longer to get it sorted. The mechanic mentioned that leaving these sensor issues unchecked could lead to more expensive problems down the line. The repair was quick too, they had my car back to me the same day. Definitely worth getting it checked out sooner rather than later!

Thanks so much for all that detailed info! Just got back from the mechanic actually. You were spot on, it was the same issue with the sensor connection. Paid a bit more than you did, around 120 for parts and labor, but I'm just relieved it wasn't the turbo! The repair was quick, just like you said. Dropped it off in the morning and picked it up after lunch. Car's running beautifully now, that annoying whistle is completely gone and it's got all its power back. The mechanic was really thorough too, checked the whole system to make sure there weren't any other potential issues lurking around. Really glad I didn't put this off any longer. After my last mechanic experience, I was pretty nervous about taking it in, but this turned out to be a straightforward fix. Definitely learned my lesson about getting these things checked out sooner rather than later! Thanks again for sharing your experience, really helped me make the decision to get it sorted!