Originally posted by Bill
I don't know how you can sleep at night knowing there's a loose nut floating around your motor...
First thing I would do is pull the pan and check for the nut. As for the ticking, if you just replaced the nut without specing the lash, that would be the culprit.
In hindsight, before pulling the pan I'd simply drain the oil and poke around in it with a magnetic probe. If that doesn't find the nut, then I'd yank it.