Rep Power: 0

Hi I got a 08 civic 1.8 manual and it was driving normally I came to college parked it it was fine. When I came back I stared it and it was squeaking I thought it might me be something with the belt but everything looks fine and the pulleys spin like they should be. Maybe they dried out and need lubrication? Idk. It squeaks kinda loud inside the car but when you come out and pop the hood it's not to loud and it sound like there's some kind of friction somewhere also it get quieter as the rpms go up and not as constant. And I noticed that if I rev it or put it in neutral when I'm driving and let go of the gas it like goes down to around 800rpm then goes to 1500 then to 1000 and then down to like 600rpm. Not sure if that has to do something with it.

 
Rep Power: 175

Is the squeaking a constant thing? Where does it sound like it's coming from?
As for the idle, take a look at this: http://www.ericthecarguy.com/honda-i...s-hunting-idle

 
Rep Power: 519

Got a check engine light on? Got codes?