My o3 impala whines while accelerating. Also does it while stepping on the accelerator while in park. The power steering reservoir is full and does not whine when turning the wheel. Car repair funds are tight so I don't want to buy a new power steering pump if that's not case. How do I check my PS pump and what else could it be that I can check??

 

hard to say without hearing the sound. take the belt off...if the noise is gone....its related to either the belt or something turned by the belt.