I had a racket like that on my PSD. Kept putting it off to find out what it was. Sure as hell it was what I suspected, the nuts where loose on the TC to flexplate, then it cost me a new TC because one of the bolts actually tore out of the TC. Why don't you eliminate that, don't cost a thing except 20 minutes, 10mm wrench for the cover, 13mm for the nuts or 1/2", a large screw driver to turn the engine over.