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philippdunkel86

BMW X5 Diesel Stumbles: Turbo Boost Sensor Mystery

Poor fuel economy

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Loss of engine power

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Stalling while idling

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Loud hissing on acceleration

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Check engine light on

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Whistling noise

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Jerking on acceleration

Hi everyone! Having some serious issues with my 2010 BMW X5 diesel (123k km) and need your input. My engine's acting up with jerking during acceleration, making weird whistling/hissing sounds, and stalling at idle. Check engine light is on, and I'm burning way more fuel than usual. Power feels significantly reduced too. I suspect it might be the boost pressure sensor, but after a recent bad experience with a mechanic, I'd like to hear from others who've dealt with similar symptoms. Has anyone experienced this combination of issues? What was the actual problem and how much did the repair cost? Thanks in advance for any help!

4 comment(s)


floriantaylor6

Hey there! I had nearly identical issues with my 2013 BMW X3 35d last year. The symptoms you're describing match exactly what I experienced, the jerking, whistling, and that frustrating power loss. Initially thought it was the sensor too, but turned out the cable harness connecting to the boost pressure sensor was damaged and corroded. The mechanic showed me how the connection had deteriorated, leading to faulty readings and the ECU reducing power as a safety measure. The repair involved replacing the entire cable harness assembly and cleaning the connector ports. While not the most expensive fix, it wasn't something I could've done myself. The fix resolved all symptoms, no more jerking, whistling stopped, and power returned to normal. Fuel consumption went back to standard too. If you're experiencing these exact symptoms, I'd strongly suggest getting the wiring checked before replacing any sensors. Best of luck sorting it out.

philippdunkel86 (Author)

Hey, thanks for sharing your experience! That's really helpful since our issues sound so similar. Quick question, do you remember roughly how much you ended up paying for that harness replacement job? Also, has everything been running smoothly since the repair, or have you noticed any other quirks pop up?

floriantaylor6

Hey again! Glad I could help! Yeah, I got it sorted just a few weeks ago, paid 95 € for the repair which was basically fixing the cable connection that was giving the sensor trouble. Pretty reasonable price, if you ask me, especially considering how much better the car runs now. And you'll be happy to hear everything's been running like a dream since then! The boost pressure sensor was definitely the culprit, once they fixed that dodgy connection, all those annoying symptoms disappeared completely. No more jerking, weird noises, or power issues. My fuel consumption is back to normal too, which is a relief for my wallet! It's funny because I was initially worried it might be something way more serious (and expensive), but it turned out to be a relatively simple fix. Haven't noticed any other issues pop up since the repair, and it's been smooth sailing. The car feels just like it did when I first got it. Just make sure you get a decent mechanic to look at it, they should be able to spot if it's the same issue pretty quickly.

philippdunkel86 (Author)

Thanks so much for all the details! I actually just got back from the mechanic today. You were spot on, it was a wiring issue with the sensor connection. Paid about 120 € for the fix, which wasn't too bad considering all the trouble it was causing. The mechanic was really thorough and showed me exactly what was wrong. Those corroded wires were definitely the source of all my headaches. Had a quick test drive after the repair, and what a difference! No more jerking or weird noises, and the engine's running super smooth now. Honestly, I'm just relieved it wasn't something major with the engine itself. Been worried sick about potentially huge repair bills. Really appreciate you sharing your experience, it helped me push the mechanic in the right direction instead of just blindly replacing parts. Car's running like new again!

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