This may sound stupid, but, try driving the car hard for a few days and see if it goes away..... I get some intermittent ticking that sounds just like that right after changing oil, however, once the oil has a chance to shear a bit it goes away completely till next oil change. I am 99% convinced it is just valvetrain noise!
2011 E90 M3 ZCP - Individual Moonstone/Individual Amarone Extended/Individual Piano Black With Inlay:LINK!!!
1994 Euro E36 M3 Sedan - Daytona Violet/Mulberry:LINK!!!