I'm sure this will be a common problem and forgive me if it's been solved somewhere here before but I'm new to the forum. I have a whirring noise behind my glovebox- sounds kinda like a CD changer swapping a CD (but it's not...mines in the boot). It cycles about every 8 seconds or so. Also, in the 4 or 5 weeks I've owned the car there has been a constant noise from behind the central blowers, it sounds like when you used to peg a playing card to your bike spokes! I just assumed something was catching on the fan motor but now I'm thinking it's linked to this other noise.
search heater recirc, mine does the exact same thing. most annoying. there are a few threads regarding tghis.
98, Executive turbo estate in aluminum silver. The stealth wagon! Now departed, New project Xsara VTR-8 in progress, Next Project, 406 D8 / JAP. So will be looking for a 406 again when the xsara is done!
Just stick "recirc" in the search box, it brings up 6 pages... Sounds like whir whir whir of the motor spinning, couple with the click click click of the gears slipping.