the whirring noise could be you air con on its way out when i had my mazda 626 it did the same and that was the end of it never even bothered to get a quote on how much it would cost to repair
just a quick one for you to look in to on the back of the engine there is a valve pipe just under the manifold as that spilt because i had the same sort of problem on my 2.3 and it cost me