I had exactly the same problem with my VS,
Whenever the wheel is turned it would make like a moan or a groaning noise.
I spoke to a holden dealer and they told me that its a common problem, its caused by a rubber boot on the steering column drying out.. All you have to do is get under the car and spray the column and the boots with CRC or WD40 or something like that.
I think the boot many be a pinkish red colour? im not too sure.
Anyway, it worked for me
Give it a go, its the cheapest solution!
Scott