I have an Audi A6 2.7T and when the temp was below 0 the car started smoking and leaking oil, now that the temp is a little warmer it has stopped smoking and the oil is not leaking out anymore. Has anyone ever had that happen before. It is puzzling!!! My mechanic had a VW with the same problem on the rack and could not find a leak, he tried dye and nothing was exsposed.

 

This is a complete guess...but how about a crack in a hose that contains oil? its cold so the hose contracts causing the crack to open slightly letting oil slowly drip out...when warm the hose expands sealing said crack and no oil can escape. Just some food for thought.