Cheverolet impala 2004 with a 3.8 engine whining noise (power steering)

Is it full of fluid ?

Air in the power steering pressure line. Is the power steering reservoir full? Check for leaks or breaks in the pressure line to ensure air is not getting into the system.

hi robin.
The first sign of fluid leaking from the power steering is a pump whine, because the fluid is low, the pump will start to make a whine noise, especially when turning the steering wheel.
If you think you may have a car power steering leak, the first thing you should do is check the power steering fluid reservoir, if the fluid level in the reservoir is low, you just might have a leak in the power steering system.
Power steering fluid has a very distinctive smell, it smells like a burnt marshmallow, that is my opinion on the smell, and I'm sure you will not find that documented anywhere on the internet or any repair manual.

If you feel the steering in your vehicle binding up, or the power steering pump starting to make whine noise, it's a good sign your power steering fluid level is getting low or it's empty. Running the power steering pump with low or no fluid could be very damaging to the entire power steering system because metal particles from the pump enter the system and cause internal failure of the steering rack and to its valve body or to the steering gear box.

The fact that you have to add fluid suggests that the pump has run dry, and been damaged. You are going to have to fix the leak and replace the pump.

hi Eva.
As you turn your steering wheel it is this fluid pressure that aids in turning the wheels of your car. ... If the pump impeller is trying to move power steering fluid and starts catching air bubbles it can cause whining noises and vibrations to occur.
Maybe you've heard it at a stop light. Maybe you've heard it as you pass a car on the freeway. Or maybe you've heard it in the parking lot at work when someone is leaving. The unmistakable whine of a power steering pump can make even the most confident mechanic wonder when that car will breakdown.
Power steering pump noise is a unique noise that your car may make and once you've heard it you always know what it is. The noise is a mix of a whirring and a whining and will always vary with the speed of your engine whether your car is driving or in park. This whining noise can be subtle or extremely loud and may be worse in colder weather, or right when you first start your car.
Power steering pumps are most often vain style centrifugal pumps that are tasked with pressurizing the power steering fluid and pushing it down to your power steering gear or rack. As you turn your steering wheel it is this fluid pressure that aids in turning the wheels of your car.
There are a few reasons why you are hearing power steering pump noise from your car. First, it may simply be due to the design of the pump. Sometimes, noisy power steering pumps can continue to work flawlessly for years after they start making noise. This may simply be due to the manufacture's design or a tight tolerance in that particular pump. In this case, you would hear the noise but not see any other adverse effect like a loss in power steering, leaking fluid or a wobbly pulley. In this case, you may be able to help reduce your power steering pump noise by choosing a different type of power steering fluid, like a synthetic fluid.
Your power steering pump may also be making noises due to air trapped in the system. If the pump impeller is trying to move power steering fluid and starts catching air bubbles it can cause whining noises and vibrations to occur. Even tiny air bubbles you cannot see that are trapping in the power steering fluid may be causing the whining you are hearing. In this case, the best thing to do is flush your power steering system to try and remove the air from the system. Having air trapped in your power steering system can be difficult to diagnose so you may need to simply try a power steering flush to see if it solves your problem.
Power Steering pump noise may also be due to a failing power steering pump. As the bearings on the impeller go bad it will start to make noise as the pump is turning. If you have a bad power steering pump you usually will also experience leaks from around the pulley, a wobbly pulley, or difficulty turning the steering wheel when you are stopped. If you have multiple of these symptoms together, it is probably time to replace your power steering pump.
Lastly, and most usually, a whining power steering pump is an indication of a low fluid level. Your power steering fluid is probably something you have rarely if ever checked, so it often comes as a surprise if the level is low. Your power steering fluid reservoir is also relatively small so even a slow leak will cause a low fluid level relatively quickly. To confirm this is your problem it is as simple as checking your power steering fluid level. Some power steering reservoirs are clear so you can see through them to check how full they are. You may have to wipe away some dirt and grime to find the "full" line, but it should be easy to check. If you have an opaque power steering fluid reservoir there should be a small dipstick under the cap that will help you measure the fluid level. If it is low, then you have a leak somewhere and topping off the fluid should quite down your power steering pump.
If you discover a power steering leak, rather than simply continuing to add fluid every time it gets low, you should fix the problem permanently so you don't have to continue to check your power steering fluid level. Replacing lines or seals can be a surprisingly difficult task due to the location of your power steering pump and steering gear or rack. The easiest way to seal your leak is to do it from the inside out!

or check this link out for more info on this matter.
Power steering whining sqreeching Google Search

grinding on front wheel is caused by 2 things. a bad or loose wheel bearing,or worn out brakes, have them both checked You might also want to check the level of fluid in the power steering reservoir - low or lack of fluid will also cause a noise (although more of a whining than a grinding).
This can also be caused by worn or damaged central velocity joints if the vehicle is front wheel or four wheel drive.

Check the level in the power steering fluid reservoir. You most likely need a top up. The noise is caused by the pump effectively pumping air through the system. Top up to the level marked in the reservoir then turn on the engine and move the steering wheel around for a wile then turn off an re top up to the level marked in the reservoir and all should then be OK. Make sure you use the correct fluid for the car – usually a Red Dexron Hydraulic Fluid.

Checking the level of the power steering is a good start. The pump is mechanical, driven by the serpentine belt, and cannot be turned off. Your steering may seem normal but if you let it go, low fluid can destroy the pump.

the suspect part for a power steering whine is the power steering pump, flush (very important) the system and replace the PS pump..