anyone ever heard of running a quart of tranny fluid, dexron/mercon, in with an oil change that stops lifter clacking on cold starts due to bleed down?

The idea behind using Dexron as an oil additive is that it is supposed to act as a cleaning agent. Intermittant lifter clatter can sometimes be cured by running a thicker oil. I've seen cases where going back to BMW synth has helped on E36 M3's, or you could try Mobil 1 0w40 which is close to BMW's 5w30 blend in terms of viscosity.

i am running 0W-40 Mobile 1 now and morning cold starts start w/clickity clack for less than 2 seconds

tried 5W-30, 15W-40 both Mobile 1, still clikity clack

See BMW TSB 110101

how does one "see TSB 110101?

Go to your BMW dealer and ask for a print out of Technical Service Bulletin #11 01 01

okay

thank you