I have a 98 Ls and My intake manifold is making a humming noise that you can hear at idle. It is comming from inside the manifold, I have all new gaskets(tb,manifold gaskets). I do have an short ram intake. I know about the whistle that the intakes make, but it is not a whistle it is a loud humming noise. It only happens at idle. I haven't a clue what it could be. Someone pleas help!