Did you find out what it was?
Chris

 

I had the same thing. ended up being an exhaust leak on the #6 primary

 

well, i pretty much eliminated the engine, although i did get to do a valve job and inspect the push rods. its something in the transmission, although not the flex plate or torque converter lugs/bolts. when i pull the trans. relay the noise stops, i guess because the torque converter doesnt lock up? maybe a bad selenoid or some thing? valve body? i don't know. i'm just relieved that its not the engine, though, as i was planning on replacing the trans. anyhow. now all i need is another 2 to 3 grand in the bank. i tryed to call some trans. guys(hts, goerend) but they were all closed due to the holidays, i assume.

 

oh yeah, it not the wastegate either. i re-torqued all the exaust manifold bolts, and didn't see any obvious signs of exaust leak, but i guess the gasket could be bad? any good way to check other than replacing it? i can't see any soot or anything around it.

 

you could try a stethoscope.