BMW Z4 Rough Idle & Shakes: Engine Mount or Something Else?

Hey there! Had a similar issue with my 2014 BMW M235i last month, that shaking and rough idle is all too familiar. The symptoms you're describing match exactly what I experienced. Turned out it wasn't the engine mount in my case. The issue was a faulty ignition coil and spark plug on cylinder 3. The garage found the connection between the coil and the plug was corroded, causing misfires. This is actually a common problem after 90k km. The fix wasn't too complex, they replaced the coil pack and all spark plugs as preventive maintenance. While not a super serious issue if caught early, it can damage your catalytic converter if left unchecked for too long. Quick tip: You can confirm if it's a misfire by checking if the shaking gets worse when the AC is on. Mine definitely did. Get it checked soon though, misfires aren't something you want to ignore.

Thanks for sharing your experience! That's super helpful since our symptoms match up perfectly. Probably going to get this checked out next week, I've noticed the shaking does get worse with the AC running, just like you mentioned. Would you mind sharing how much the coil and spark plug replacement set you back? Also, have you had any other issues pop up since the repair? Just want to make sure I'm prepared for any potential related problems.

Hey again! Happy to give you an update. Actually, my case turned out differently than I initially thought, it wasn't the ignition coil after all. When I finally took it to the mechanic, they diagnosed a defective engine mount, which they fixed up nicely. Also had a cable connection issue they sorted out for 95 bucks. Since getting those repairs done, my M235i's been running smooth as butter, no more shaking, no more rough idles, nothing. It's like driving a different car! Haven't had a single problem pop up since then, which is a huge relief. Honestly, getting it fixed was totally worth it. I was worried it might be something more serious (and expensive!), but turned out to be pretty straightforward. If your symptoms are similar to what I had, definitely get it checked out soon. Better to catch these things early before they turn into bigger headaches, you know? Let me know how it goes when you get yours looked at, always interested to hear how these things turn out!

Just got back from the mechanic and wanted to close the loop here! You won't believe it, it was actually a combination of issues. Had a worn-out spark plug like you initially suggested, but also a cracked vacuum hose that was causing the extra vibration. The mechanic showed me the old parts and everything made sense. Total bill came to about 300 bucks, not as bad as I feared. They got it done in a couple of hours, and honestly, the car feels brand new now. No more shaking, engine's purring like it should, and that error code is gone. Really glad I didn't wait any longer to get it checked out. Thanks again for pushing me to get it looked at quickly. The mechanic said catching it early probably saved me from bigger problems down the road. Think I've finally found a trustworthy shop too, they were super transparent about everything and didn't try to upsell me on stuff I didn't need. What a relief!