BMW M4 Rough Idle & Vibration Mystery Needs Solving

I had similar issues with my 2019 BMW M2 Competition. The symptoms you're describing sound exactly like what I experienced, rough idle, vibrations through the whole car. Turned out it wasn't the engine mount at all. My mechanic found that the ignition coil connectors were loose, and two of the coils were failing. The connector pins had corroded a bit over time, causing poor contact. They had to replace two coils and clean the harness connectors. It wasn't a major repair job, but it definitely needed fixing before it could cause more serious problems down the line. I'd suggest having a professional check the ignition system first before looking at engine mounts. These symptoms are classic signs of ignition system issues in these engines. With your mileage, it's about the right time for coils to start showing problems. Hope this helps narrow down your search. Let us know what you find out.

Thanks for sharing your experience! That's really helpful info about the ignition coils. Just had mine fixed about 2 weeks ago and the symptoms do sound identical. Can't remember exactly how much I paid for mine though. Do you recall what the total cost was for your repair? Also curious if you've had any other issues pop up since getting it fixed?

Hey there! Glad I could help. Just to update you, I actually misdiagnosed earlier when I thought it was the ignition coils. When I took it to my mechanic, they found it was actually a defective engine mount causing all those vibrations and rough idling. They also found a cable connection issue that needed fixing. The total repair came to 95€ for fixing the cable/plug connection component. Since getting these repairs done, the car's running smooth as silk, no more vibrations or rough idling. Haven't had a single issue pop up in the past months. It's funny how similar symptoms can point to different problems, right? That's why it's so important to get a proper diagnosis from a good mechanic. My M2 Competition is purring like a kitten now. Have you noticed a big difference since your repair two weeks ago?

Thanks for the follow-up! Yeah, you're totally right about getting a proper diagnosis. So, I finally got my car back from the shop last week. Turned out my problem was actually a combination of things, bad spark plugs and a worn-out engine mount. The mechanic I found was really thorough and spotted both issues right away. The repair ended up costing me more than your cable fix, around €800 total, but it was worth every penny. The difference is like night and day! No more shaking when I'm stopped at lights, and the engine sounds way healthier. I've put about 500 km on it since the repair, and it's running perfectly. Really appreciate you sharing your experience, it helped me feel more confident about getting it checked out. These cars can be tricky sometimes, but when they're running right, there's nothing better!