300E/M103 high freq. vibration
On the '87, I've got a high frequency rhythmic vibration that's slowly gotten worse over time. Sort of a "droning" or "thrumming" that others have mentioned in other posts. Starts being noticeable around 55-60 mph, eases up around 70, and comes on strong around 80-85 mph. I can feel it in the seat of my pants, through the accelerator, against the door, and through the gear shifter. Have finally decided it's bad enough that it will be the next repair item, once my credit card recovers from a new set of tires and front end work on the '91.
-Suspect engine, which has a slight stumble at idle, and a much lighter version of vibration when revved in neutral to 3000 or so.
-Motor mounts changed a few months ago, helped a little, but not for very long.
-Rotating/balancing/new tires made no difference.
-Center bearing support changed (for a different vibration, which went away, then came back... fun!) a couple of months ago, no difference.
-Vibration worses when accelerating, lightens up as I ease up on the gas pedal. As speed falls away, the vibration goes from high frequency to low frequency, then disappears eventually.
Looking for a place to start..
2000 C 2 3 0 Sport :: 180k