After opening up my 2013 R56 N18, I pulled off the head and had it rebuilt. When it was returned, they had removed all the pumps that I'd left attached, it had 3 small bolts I didn't recognize. Silver in color, cylindrical torx head. (you can see one in the attached Pic, resting on the heat shield, blue arrow).

After reassembly, and filling the coolant. I got a leak out of a threaded hold in the head. I put on of the bolts into this hole, and the leak stopped. (you can see the bolt in the hole in this Pic, yellow arrow.)

Any ideas where these two boys should be, or if I'm supposed to use something else to plug this hole?

Thanks for any tips.