Power steering noise 98 Deville

My 98 Deville has a horrendous noise in the steering column when I turn the wheel to the right or left. It sounds like pressure cavitating as the wheel is turned either way. It's a very loud, pulsating noise. I don't know if it's the pump or whatnot. There is fluid in the power steering pump. Can anyone offer some advice as how to diagnose the power steering pump or system? The car has 100,000 miles, I've never seen a PS pump go out on a dozen GM cars that I've owned. Help! Thanks!

Is the serpentine belt slipping due to wear or is the belt tensioner not exerting tension on the belt? Also, relieve the tension on the belt with a breaker bar and spin the pump pulley by hand. Does it appear to be binding up?

Yeah, I'll look deeper today, I don't think the belt is slipping. When I turn the wheel either way, the PS pump vibrates and makes a terrible noise, it only stops when the wheel is straight ahead. I think I have a bad pump since that's where the vibration is. The good news is that the PS pump is located perfectly right on top of the engine and Autozone has them for about $65 so if that's the problem, I'm home free. Will post when I find out what happens. Thanks.

My 98 Deville has a horrendous noise in the steering column when I turn the wheel to the right or left. It sounds like pressure cavitating as the wheel is turned either way. It's a very loud, pulsating noise. I don't know if it's the pump or whatnot. There is fluid in the power steering pump. Can anyone offer some advice as how to diagnose the power steering pump or system? The car has 100,000 miles, I've never seen a PS pump go out on a dozen GM cars that I've owned. Help! Thanks! Hi.. your powersteering pump is more than likely PUGGED...One day it's going to just quit...It's not fun trying to steer a big hog....