I have experience also, some ideal :)
1.) check steering oil level enough or not?
2.) check there's any rubber torn, specially the pump area, sand might go in.
3.) or sometime if turn the steering to dead end dun release, it will sound like that also, any how the steering pump should have problem...time for service :D but seldom mechanic wan to do that, coz need to dismantle many parts, try flush the entire power steering system lo :)
4.) another scene is slow turning in the conner the sound (klo klo..) will come, those might b drive shaft rubber have torn & the oil inside have leak, better get to service faster if not need to change entire drive shaft, kao eh XD
5.) and also when slow turning in the conner with some bumping road, there some sound (ek ek...) like metal rubbing, the steering rod which connect to lower arms rubber might torn, need to change :)
Hope this help.