"那个泪珠在里面一层" ?

I would send it in now. Nikon has a service center in Melville, NY. I don't know if they do walk-ins there but if they do I will bring in the lens in person and give them an earful. Who knows they might as well do it under warranty. In the meanwhile you can pick up a cheap nifty-fifty so you don't totally miss out the fall colors.