BMW 1 Series Diesel Multiple Issues, Boost Sensor Help

Hey there! I had a similar issue with my 2004 BMW 3 Series diesel. I'm a hobbyist with some basic car maintenance experience, but this one needed professional help. My car showed pretty much identical symptoms to yours, engine light, jerking, weird noises, and that annoying power loss. Turned out to be a faulty cable connection at the boost pressure sensor. Got it fixed at my workshop, they replaced the wiring and connections. Cost me 95 Euro and solved all those problems. Which 1 Series model do you have exactly (116d, 118d, etc.)? That would help me share more specific details about the repair. Also, have you noticed if the symptoms get worse in any particular driving conditions?

Thanks for sharing your experience! I have the 118d with 62585 KM on the clock. The symptoms definitely get worse during highway driving, especially when trying to overtake. I'll have my regular workshop check the wiring connections first, that seems like a sensible starting point considering your experience. Really hoping it's just the wiring and not the sensor itself. The car's been pretty reliable since the last service, so this caught me off guard.

Oh hey again! Glad to help further with your 118d issue. Yeah, my 320d had around 70000 KM when I faced these problems. The highway symptoms you mentioned are exactly what I experienced too, it was super frustrating trying to overtake with that power loss! Just to add to my previous reply, after they fixed the wiring, my mechanic actually showed me the corroded connection. It was pretty nasty, and apparently quite common in these models. The moisture gets trapped there over time and messes with the sensor readings. Quick tip though, after my repair, I got my mechanic to add some dielectric grease to the new connections to prevent future corrosion. It's been two years since then, and I haven't had any issues. Might be worth asking your workshop about doing the same. Also, given your mileage is similar to what mine was, it's probably the same issue. If they do end up saying the sensor itself needs replacing, get them to double-check the vacuum lines too, they're often overlooked but can cause similar symptoms. Keep us posted on what your workshop finds! Always good to know what fixes work for different cases.

Thanks so much for those extra details, especially about the dielectric grease tip! That's exactly the kind of practical advice I needed. I've booked the car in for tomorrow morning, and I'll definitely mention checking the vacuum lines as well. Will ask them about the grease protection too, seems like a smart preventive measure. Really appreciate you taking the time to share your experience so thoroughly. You've made me feel a lot more confident about dealing with this issue!