Check the wheel bearings
if it is only when you turn, you may want to check the backing plate as if it gets bent or warped, it can rub on the rotor as you turn. I had that problem, and a simple bend into shape and it was fixed.
Check out the bearings in the steering column and the knuckles in the steering shaft
most grinding noises that come from turning is usually a cv axle that needs to be replaced. Can also be a bad wheel bearing. If you hear the grinding when turning to the right then the left front wheel bearing is bad.
Bad wheel bearings usually cause a grinding noise, and are known to only cause it when turning.
The steering gear box, probably. If it's power steering, it may be coming from the pump itself. This answer could be one of many things, if the grinding only happens while you are driving. Check to make sure your power steering fluid is full. Mine has a leak and every couple weeks it starts to grind when I turn right.
Many things can cause that, the simplest cause being lack of power steering fluid.
A bad alternator. Turning the steering wheel all the way is very demanding on the power steering which draws power from the engine and can cause the idle to dip down. A weak alternator is usually the cause for the stalling.
Low steering fluid can cause a steering wheel to whine when turning. A worn steering belt can also cause a steering wheel to whine when a car is being turned.
ummm power steering
Possible causes of popping/grinding noises when turning:Wheel bearingsCV joint / axleBrakesSee "Related Questions" below for more
Have your brakes checked, rust or wear on brakes can cause grinding when turning.
Check and see if your power steering fluid level is low.
Anytime I've ever heard a humming noise when turning the steering wheel on any vehicle,It has always been due to low power steering fluid