I am having something unusual happening on my Fabia (2000 8v). Sometimes, maybe once in a week, a noise appears from the engine compartment that rises/falls with the revs, it happens when in gear and when the clutch is depressed. It's a very low pitched whine, like a cat's growl. Thats probably the closest thing I could compare it too. It's simply stopped by switching the engine off and back on again

I wouldn't worry about it, my VRs makes loads of odd noises, as long as your fluid levels are ok i'm sure you'll be ok.