Steering Wheel Shimmy

I just started a new job. My commute has gone from 2.7miles one way to 15miles one way. I have noticed a mild shake in the steering wheel on occasion. It doesn't happen all the time and when it does, it's not violent.

Is this likely to be an engine or transmission issue? Perhaps it's just the road in spots? Am I being a hypochondriac?

Does it happen under load only (acceleration) or braking? Year and model would help.

2001 330xi. It seems to happen during acceleration around 3000 or 4000rpm but I've only noticed it at high speed and even then, it's not consistent.

Had a similar problem in the 03 xi. I had two problems:

1) drivers side control arm was shot
2) passenger side caliper was frozen

I would rule out the engine. Before the dealer (parts changed under CPO except for the arm) fixed my problem they thought it could be either the differential or the driveshaft.

Autohaus - with a sticking or frozen caliper, would it pull a bit to one side while driving?

I guess I could just look to see if a caliper has seized, yes? Just look behind the tire?

If a caliper is sticking, is there something I can do to it to stop it or would I need to replace the caliper?

I didn't notice it, however, I noticed lots of brake dust on the passneger side wheel.

The caliper would need to be replaced.

If it only happens at a certain speed, it might just be that the wheels need to be balanced again.

Thanks for all of the replies. Turns out the wheels were out of balance after all.