What would make a whirring vibration in the front passenger side of the car?

I have a loud whirring vibration in the front passenger side of my car. You can also feel it in the gas pedal when it makes the noise and its loud enough that someone standing 15-20 ft away can hear when it does it. It doesnt have a vibration or pull in the steering and it seems to do it it whether ur pulling out or already in motion and it does it every 30 sec estimated, maybe a little longer. However, it doesnt seem to do it when slowing down and it isnt a hum like a wheel bearing and it isnt a whine like a power steering pump.