So recently, the car doesnt make such sound when i drive it and such, but when i'm in neutral for a while and the car fan like suddenly turn on really loud to max to cool down the car or something (which iono), and then it turn off. Basically it turn on and off when i'm resting my car in neutral. IT really LOUD, but it never done dat before.

So wat ur take on it?

 

Check if the bearings for your fan motor are bad. See if the blades are "loose". It will cause some noise.