Reading about potential problems with parts of your car can really help when they start to make noise and indicate a potential fault. Then you can decide whether it is an immediate problem, or one that can wait for a service.
Low or Contaminated Fluid
A whine, which is changing when doing cornering and increases when steering is locked is a clear sign for low oil or contaminated oil. The steering pump is unable to move the oil effectively in the hydraulic system.
Air in the System
A gurgling or even a groaning noise when you apply locking into a turn indicates air in the system. Here we have a problem that is easily identified by looking for cracks in the hoses for the steering pump. Will often develop near the clips where the hoses sit on the pump itself.
Worn Drive Belt
This sound can also be caused by a slipping or glazed drive belt. The intermittent squealing noise usually disappears when the belt has warmed up.
Internal Wear
A whine of a constant pitch, often getting louder as you go faster, can be caused by a worn steering pump’s vanes and/or rotors. These parts are designed to wear over time, leading to heavier and noisier steering. Details of how a hydraulic power steering system works and how internal wear can cause a lack of pressure to develop, resulting in the pump becoming noisy, can be found here.
Bearing Failure
A rumbling or knocking sound, particularly if it is constant and not dependent on steering position, can be caused by a failing bearing within the pump. There is more on Skoda Fabia Steering Pump at https://westernpowersteering.co.uk/vehicles/skoda/skoda-fabia-steering-pump-2000-2015/.
Identifying the noise you are hearing saves time and could prevent you from ordering the wrong part for your car.