My 98 gtp did that too the exact same thing .i changed lim gaskets and still did it.so i said f-it.one of my friends was selling a eaton m90 snout that he got rebuilt,got lazy and never put it on,then sold the car.mine was starting to rattle so i replaced it with the rebuilt one and it stopped.So i think it was somehow burning the supercharger oil.not only that when i checked the fluid it was always a little low with no visible leaks. Im not saying this is your problem,just telling you what happened to me.hope this helps you out.
