94 Civic LX squeling Noises Problem

I drive a 94 Civic LX, and recently had the transmission fluids changed with my last oil service a week ago. Moreover, I am familiar with the "squeling" that accompanies Civic semi-metallic brakes over time.

During this past week, however, there is a highpitched whirring/squeal that comes and goes when I am driving/accelerating, and not when I brake.

I am wondering if perhaps there is a belt loose/some slippage in the transmission (shifting is fine), or if this is a brake issue.

Any ideas would be great...

Thanks,
Will Simple; Drive it for about 20 minutes. Park and go from wheel to wheel if it is hot or hotter than the others then you have braking problems. Probably a bad cylinder.