X5 Trans Sensor Failure: Grinding Gears & Warning Lights

I faced a similar situation with my 2017 BMW X3 30i last year. The symptoms were almost identical, transmission warning, rough shifts, and that annoying grinding noise. Initially thought it was just a sensor, but when my mechanic checked, the gearbox oil level was critically low, which caused the temperature sensor to act up. The oil had been slowly leaking through a worn-out seal. The fix wasn't just topping up the oil, they had to replace the seal and do a proper transmission fluid flush since some metal particles were found in the old fluid. This was actually serious because running low on transmission fluid can cause permanent damage to the gearbox. The car has been shifting smoothly since then, no warning lights. I'd suggest getting it checked soon because these symptoms shouldn't be ignored. Low transmission fluid can quickly lead to bigger problems. Good luck with yours, those symptoms definitely need proper diagnosis at a transmission specialist.

Thanks for sharing your experience! It's actually really helpful since my X5 seems to be showing the exact same symptoms. Been worried it might be something major. You've got me thinking it could be a leak too, especially since I've noticed some small drops on my driveway recently. Do you remember roughly how much the whole repair set you back? Also, has everything been running smoothly since the fix, or have you noticed any other transmission-related issues pop up?

Hey there! Happy to give you an update on my X3 situation. Since getting it fixed last year, the transmission has been running like a dream, no more grinding, no warning lights, nothing! The mechanic nailed it when they diagnosed the faulty transmission oil temperature sensor and low gearbox oil level. Both issues were sorted out in one go. The total repair came to 365 €, not exactly cheap, but way better than having to deal with a completely fried transmission! And honestly, considering how smoothly everything's been working since then, I'd say it was money well spent. Just want to stress, those drops you're seeing on your driveway? Don't wait around on that. That's exactly how mine started, and catching it early probably saved me from some serious transmission damage. The peace of mind knowing it's properly fixed is worth every penny. Haven't had a single transmission problem since the repair. It shifts like new now, just like when I first got the car. Let me know how yours turns out!

Thanks for all the detailed info! Just got back from the mechanic today actually. You were spot on, it was indeed a transmission fluid leak from a worn seal, plus a faulty sensor. The whole thing cost me around 400 €, which isn't too terrible considering what could've happened if I'd left it longer. The mechanic showed me the old fluid and yeah, it was pretty nasty looking. They did a complete flush, replaced the seal, and put in new fluid. The car's running so much better now, no more grinding sounds or rough shifts. Those warning lights are finally gone too! Really glad I didn't put this off any longer. The mechanic mentioned I was lucky to catch it before any serious damage happened to the transmission. Thanks again for sharing your experience, it really helped me understand what I was dealing with and pushed me to get it sorted quickly. Definitely learned my lesson about regular maintenance checks!