Hi All,
I've contacted pentax, and they said it sounded strange and that I should send it in...so...I'm on the bench for 15-20 days.
As for "dark frame subtraction" the fizzing noise is definitely there for long exposures, but I switched to 1/4000 and still heard it after the mirror clicked back down. It is even there when I put the camera into "sensor cleaning" mode so I don't know if "dark frame subtraction" would be taking place then.
It isn't the same noise as the rattle of dust removal. It is fainter and sounds like static/fizzing I wish I could record it and put it on the forums.
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I'll just pay for the shipping and have a tech look at it and advise. Thanks everyone for your help!