I noticed in my 02 Cooper (5 spd/13k miles) when accelerating in first gear and second using half throttle or so between 2-3k rpms there is a noticeable vibration felt through the steering wheel and floor. It feels almost like a tire is out of balance. It is a relatively slow feeling vibration. Anyone else experience this?

It has not been affected by switching wheels and tires, and with a new flywheel, clutch, throwout bearing, etc. I do not remember either my 03 or 06 Cooper S exhibiting this behavior. Could it be a Cooper only thing?

I know one of my strut towers is mushroomed pretty good which throws the alignment off slightly (I am waiting until I get a strut brace to pound the tower back). Could that cause it? It is only when accelerating. Thanks!

 

Also, some more things to mention. It happens in a straight line, with the AC off. It might be better to describe it as a wobble instead of a slow vibration. MINI2 posts hint at wheel bearings or a driveshaft/axleshaft.

 

Wow, a new flywheel, clutch, etc. and mushroomed strut towers at only 13K miles.

My 03 MC, (5-speed/10.5K), sometimes has an engine vibration while accelerating that sounds simular to your description. I think it's normal.