For the last couple of weeks my 98 prelude has been making strange noises. The noise isn't always there its just sometimes when i start the car up in the morning (when the engines cold) and also when i come out of class and its really hot outside i will hear the noise. the noise sounds very similar to a garbage disposal, but its not as loud as one. the noise will be there for a few minutes and then it will go away. you can only hear it when your idling and at really low rpm's and its coming from the engine bay. There is nothing caught in the fans or anything i ran a compression test and i got 205, 200, 210, and 205. Im not throwin a CEL or anythin and the car runs great, I just hear that weird noise from time to time. does anyone know what it could be?