Hello and welcome to the forum.
The tappets are adjustable,although I'm not sure what system of adjustment is used on this engine.
The clearances (with a cold engine) should be;
Hope that helps.
I'd rather push my Alfa than drive a BMW....
Currently in Lagdti's garage:
2003 Alfa Romeo 156 2.4 JTD Sportwagen (estate to you and me!), 2002 Alfa Romeo 147 2.0TS Lusso soon to also be in many pieces,and now a 1994 Land Rover Discovery 300Tdi with a 2'' lift kit and some girt knobbly tyres on it....