BMW 8 Series Shaking: Engine Mount or Something Worse?

Having experienced similar issues with my 2016 BMW 5 Series diesel, I can relate to your situation. Last month, I had my car at the garage with almost identical symptoms. After diagnostics, it turned out the problem wasn't the engine mount but rather a faulty fuel injector connection. The wiring harness had deteriorated, causing inconsistent fuel delivery to one of the cylinders. The rough idle and shaking were definitely concerning, but it wasn't a catastrophic issue. The repair involved replacing the wiring harness and checking all injector connections. They also cleaned the injectors while they were at it since everything was already opened up. Just a heads up, ignoring these symptoms isn't a good idea as it could lead to more serious fuel system damage. I'd suggest finding a different mechanic if you're not comfortable with your previous one. Ask specifically for them to check the fuel delivery system and injector connections before jumping to engine mount conclusions. This was a moderate repair job, not a quick fix but definitely not engine rebuild territory either. Worth getting it sorted sooner rather than later.

Thanks so much for sharing your experience! That's really helpful information about the fuel injector connection. If you don't mind me asking, what did you end up paying for the whole repair? Also, has everything been running smoothly since then, or have you noticed any other issues pop up? I'm trying to get an idea of what I might be looking at cost-wise and whether this typically solves the problem completely.

Hey again! Just wanted to follow up and give you an update since my last post. Actually, I was wrong about the fuel injector being the culprit, turns out it really was the engine mount after all! When I took it to a different mechanic, they spotted it right away. The repair was way simpler (and cheaper) than I expected, just 95€ to fix a faulty cable connection related to the engine mount component. Since getting it fixed, my car's running like a dream, no more shaking or rough idle issues. Complete night and day difference! It's been about three months now, and I haven't had a single problem since. Really glad I got a second opinion on this one. Sometimes the simplest explanation is the right one, I guess! My 5 Series is back to being that smooth ride I remember. Feel free to ask if you need any other details. Always happy to help another BMW owner out!

Thanks for the update! I actually just got back from the mechanic today. Took your advice and tried a different shop, really glad I did! The issue turned out to be pretty similar to yours. The mechanic found that one of the engine mounts had worn down, causing all that shaking. Got it fixed up right away, and honestly, the difference is incredible. The car's running super smooth now, no more weird vibrations or rough idle. Cost me a bit less than I expected too, around 120 bucks including labor. The whole thing took just a couple of hours. Can't believe I was stressing so much about this! Should've gotten it checked out sooner. Really appreciate everyone's help and advice here, definitely saved me from worrying too much and helped me make the right call on switching mechanics. Think I've found my new go-to shop too. The mechanic was straight up with me and even showed me the worn-out mount. Always good to find someone you can trust with these things!