When turning left or right I hear and feel a grinding noise in the steering wheel in my 1999 Buick Prk Ave. Ultra.

It's a good chance that it's either wheel bearings or the CV joints.

the grinding noise is from the steering pump going into overload and the pressure relief valve is working. If you have recently worked on the pump or steering check that the hydraulic lines have correctly installed It appears that when turning right the steering is trying to turn left.

this might help:
Here is the Technical Service Bulletin that maybe of help, worth looking into but can't guarantee that it would fix your problem Steering - Steering Column Clunking When Turning TECHNICAL Bulletin No.: 01-02-32-001P Date: November 25, 2009 Subject: Clunk Felt/Noise Heard From Steering Column, Steering Gear and/or Front Of Vehicle During Turning Maneuver and/or Steering Wheel Rotation (Replace Intermediate Shaft As Directed) Models: 2001-2004 Buick Regal 2005-2008 Buick Allure (Canada Only), LaCrosse 2000-2008 Chevrolet Impala 2000-2007 Chevrolet Monte Carlo 1998-2002 Oldsmobile Intrigue 2004-2007 Pontiac Grand Prix Supercede: This bulletin is being revised to add the 2008 Buick LaCrosse/Allure. Please discard Corporate Bulletin Number 01-02-32-001O (Section 02 - Steering). Condition Some customers may comment on a clunk type noise coming from the front of the vehicle while driving during a turning maneuver.
1. Locate a large area (parking lot) where the vehicle can be turned in a tight circle. 2. Turn the steering wheel to the right and/or left all the way to the steering lock, then off the steering lock a 1/4 turn. 3. Drive the vehicle approximately 5 km/h (3 mph) in a circle, preferably over rough pavement or seams on the road surface. 4. Drive the vehicle straight ahead at idle speed while applying and releasing the brake pedal. Listen/feel the steering wheel for the clunk/noise condition. 5. If a clunk is felt in the steering wheel, the MOST likely cause is the I-shaft - not the steering gear. Continue with the correction. Correction DO THIS - Replace the intermediate shaft DON'T DO THIS - DO NOT lube the intermediate shaft Replace the existing intermediate shaft

Check front tyres & wheel bearings espesially the R/H/F. Feel tyre for high / low spots on inside & jack up & spin wheel if you get noise while jacked up it is not the tyres but wheel bearing or brake pads but more than likly a crook bearing by the sound of it. It needs to be tended to ASAP

I would first of all check the power steering fluid.

possibly your ball joints, or a wheel bearing starting to go

Have your CV joints inspect.

sounds like a wheel bearing if you don`t hear a clicking it is a bearing

if you feel it in steering wheel it could be your front axels. jack up the front end of your vehicle and turn the steering wheel to which ever way you hear it most, roll the wheel with your hand and see if you hear any noise [email protected]

there is a recall from the dealer that they will fix this