My 00'L is making some weird type of noise when it idles no matter whether it be when it is first started or driven for an hour. The noise can be described to be some kind of hissing sound. It kinda sounds like if the truck had a novi 1000 or a procharger. This sound is really worrying me and would like to know what the hell is going on. Ohh by the way I thought It might have been the belt slipping but it isnt because I do not lose boost.