Whirring/grinding noise 2002 intrigue on startup

[Thornes]

I have a 2002 intrigue and only when i startup after leaving it for a few hours or more, i get a loud grinding/whirring noise from the engine(sounds like an old hard drive spinning up), it lasts about 30 seconds, then it stops (kind of like turning off the old drive). I took it to a mechanic and he said a hose was off and put it back on (and couldn't locate the source because it dropped off so fast), the sound dropped off quite a bit for a while, now the sound is louder than ever (maybe the hose fell off again). I looked around a few weeks ago and found another forum about some kind of air intake fan motor being bad or something (i am not a car guy). The car runs fine, no problems when on the road. Is this something i should be worried about? And should i take it in again to get them to see if the hose fell off again?
Thank you for any help you can give me.