BMW 3 Hybrid Transmission Grinding & Warning Lights Issue

Hi there! I have some experience working on cars and faced something very similar with my 2015 BMW 5 Series Hybrid (also had a 7 Series before). Had the exact same symptoms, transmission warning, check engine light, and that awful grinding noise. Took it to my regular workshop and turns out the gearbox oil level was critically low. They did a complete oil level check and top-up, plus they found some metal particles in the old oil which indicated wear. Total cost was 365 Euro for the service, including the new oil and labor. Since then, it's been shifting smoothly with no warning lights. Before I share more specific details, can you tell me: Current mileage on your car? When was the last transmission service? Are you noticing any oil leaks under the car? This could help pin down whether you're dealing with the same issue or something else entirely.

Thanks for your detailed reply! I'm at 17345 KM and just had my regular service last month. I haven't noticed any oil leaks under the car, which makes me wonder if it's something else. Your experience with the oil level issue is really helpful though, I'll definitely have that checked first. The grinding noise is exactly what I'm experiencing too, especially during gear changes. Did you have any issues with the car going into limp mode before you got it fixed?

Hey again! Yeah, my BMW actually did go into limp mode before I got it fixed, very similar to what you're describing. Mine acted up the same way at around 18000 KM, so we're talking about similar mileage here. Since you mentioned you had your regular service last month and aren't seeing any leaks, I'm starting to think it might not be the oil level in your case. You know what? After reading your latest update, I'm remembering something else, before I discovered my oil level issue, I initially thought it was the transmission temp sensor too. The symptoms can be really similar. But here's something interesting, when my -in-law had his BMW 3 Series (same generation as yours), he had identical symptoms, and it turned out to be a faulty valve body in the transmission. Cost him a bit more than my oil issue fix, but it sorted everything out. Given that you've just had a service and there's no visible leaking, I'd suggest getting the transmission temp sensor and valve body checked specifically. The workshop should be able to run a proper diagnostic to pinpoint exactly what's going on. Have you noticed if the problem gets worse after the car's been running for a while? That might help narrow things down a bit.

Thanks for all this helpful information! That's really interesting about your -in-law's valve body issue, it does sound very similar to what I'm experiencing. And yes, actually, I've noticed the problem does get worse after about 15-20 minutes of driving, which now that you mention it, could point toward either the temp sensor or valve body. I think I'll take it to the workshop tomorrow and specifically ask them to check those components you mentioned. Better to get it sorted quickly before it potentially causes more damage. The fact that you faced something similar at around the same mileage is quite reassuring, at least I know I'm not dealing with something completely unusual. I'll definitely update the thread once I get it diagnosed and fixed. Really appreciate you taking the time to share your experience and help me narrow down the possible causes. It's given me a much better idea of what to discuss with the mechanics.