2006 BMW 530i overheats, what is the most common cause, is there any recalls involved ?

there could be a few reasons!
1)Start with the expansion tank( make sure that the water system is bled properly and there is no airlocks in the system and DON'T FORGET THE ANTI FREEZE!!
2)The thermostat housing , this is normally a problem on the M54 engine!
3)In general have a look at the cooling system for signs of a leak, heater hoses,supply and return radiator hoses and under the intake manifold.
4)if the engine has over heated to the point that it would not star or stopped running ! well then you would not be looking at all of these things and should pull the motor and look at the damage from a better angle and possible replacement? there could be a few reasons! 1)Start with the expansion tank( make sure that the water system is bled properly and there is no airlocks in the system and DON'T FORGET THE ANTI FREEZE!! 2)The thermostat housing , this is normally a problem on the M54 engine! 3)In general have a look at the cooling system for signs of a leak, heater hoses,supply and return radiator hoses and under the intake manifold. 4)if the engine has over heated to the point that it would not star or stopped running ! well then you would not be looking at all of these things and should pull the motor and look at the damage from a better angle and possible replacement?