I have a 2006 Sedona that has power steering whining. Mechanic is stumped, they have cleaned the screen out, bled the system, used a vacuum pump on it to make sure there is no air in the system. It still whines and you can hear it more inside the cabin than outside. Any ideas? It gets louder when turning or turning the steering wheel to it's limits on both sides. There is no issue with steering, as in, it is not difficult to turn but it is so annoying to listen to. Fluid levels are also good, no leaks. Thanks in advance!