The mechanic looked into it with a plumbers camera and didn't see anything behind or on top of the tranny. He's almost certain that there is a leak under the bell housing on the tranny and is planning on removing it to see whats going on under there. I did read some other comments that there is a coolant hose that can't be reached unless the tranny is out. Thanks for your responses

I've always said this...if you're around 100k, you need to replace EVERYTHING that coolant touches. Hoses, waterpump, thermostat, radiator, expansion tank, valley pan gasket, etc. 5 and 7 owners have learned that doing parts here and there repairs on the V8 is more of a headache. Once one part wears out and is replaced w/ something new, another part of the system is soon to follow. A complete cooling system overhaul may be the most expensive option, but it's cheaper to spend $1000 now that $12,000 on a blown engine when it overheats....ask myself and tons of others on the other boards.