1993 2.5 L 5 speed - whole car shakes when the fan starts. Is there supposed to be balancing weights on the fan blades? Feeling the fan it doesn't seem to be a bearing out and the motor has a bit of a squeek, but turns freely.

Sounds like the fan is out of balance. Is it a metal fan? If so, you should be able to bend it a little.

Could the idle be set too low, then when the fan kicks on the drag of the alternator takes it even lower momentarily, and the shaking is the engine trying to recover?

Fan motor bearing was shot. Got a new one at the wreckers. Shake is gone. Thanks.

Thanks for the fix.