Hi,
Have a 97 sable that screeches when standing still or moving when the steering wheel is turned all the way to the end either left or right.
It's intermittent. It sounds like metal against metal. I've taken it to the mechanic... and they are thinking it's the power steering pump bearings are the cause. The problem is they are not sure that if they replace it.. the sound will go away and it could be caused by something else.

Any thoughts?
Thanks

 

A lot of times the high pitch screech it caused by the airbag 'clockspring' or called the sliding contact behind the steering wheel..

 

Being a 97, has the belt ever been replaced? Turning the wheel all the way to the stop blocks and not releasing a little exerts additional hyrdraulic pressure on the P/S pump and causes an additional load on the drive belt. The sqealing may also be caused by a polished belt.

 

After reading the post again, I'd be inclined to agree with Use Common Sense.. If the 'squeal' is more noticed against the stops, or with the steering wheel cranked over center and the throttle snapped and it then gives you a squeal/chirp then it's probably a belt or a tension issue.. A clockspring noise would be a high pitch 'screech' or scrapping sound when the steering wheel is rocked back and forth, or noticed over the full rotation of the wheel and only heard from the vehicle interior..

If the belt is aged, glazed, rib cracked, it would be suspect.. Then with the belt removed during the change or for a noise diagnosis, inspect the pump, idlers, tensioner.. If the pump bearings were failing it may generate a growl or whirring sound at higher engine speeds even when not turning..