I have used the Nikon 55-200mm VR and the 70-300mm VR. Both made some noise, a soft clunk for the 55-200, and a more pronounced click for the 70-300.
My Sigma 150-500 OS is also audible.
So some noise is normal on VR/OS lenses.
The only precaution that I use with VR lenses is to make sure that the VR switch is 'off' before I turn the camera off. Otherwise the VR mechanism can apparently move about.
Edward