when the clutch is engaged there is a loudish whirring noise. on 2007 Kia Sportage

It isn't hard to shift - but it's definitely making a that the master or slave cylinder - or the actual clutch?

Asked by for the 2007 Kia Sportage
It's most likely the throw out bearing. If this is the case the transmission will need to be removed to access the bearing. Once you are in there it's better the replace the entire clutch assembly.
1 more answer
Possible release bearing, however the trans. will have to be removed to replace this part so if that is your trouble, replace entire clutch assembly.