Rough-running W124

[smharr4]

My 1993 300E2.8 has been as solid as a rock the past few years, but the past few days it's been behaving oddly.

Yesterday while I was waiting for a friend in a parking lot it sounded like it misfired briefly, but continued running as normal.

The next time I started it up, it was really running roughly with really strong vibrations, as if it was about to stall out on me.

I got the car home, noticing that the vibrations seemed to go away once the car was above 35mph. I started the car up again this morning and the vibration was still there.

Any ideas, anyone?