My 02 Marathon Air is making a funny noise when it compresses, it whistles, almost chirps like a bird. I haven't really noticed any performance differences, but there is a teeny tiny bit of oil leaking (Not even a leak, more like a little residue) from where the stanchion meets the crown. 02 was Zokes "lemon year" so I'm a little worried about what could be going on. To my understanding the air cartridges were just replaced (I bought it used a couple months ago), so I don't think it could be leaking air. Anybody know what could be causing this?