Cooling System for BMW TI 318

[Michael Can]

I am trying to find out the name of a part in the cooling system. It is on top of the block under the fuel rail & or manifold.It is plastic & has one small coolant hose attached to it.The part broke while the car was @ idle,the car has not ran hot or had any other problems until this.There is a little over an inch of a nub left & it has one groove left in it.I can get to it without having to take every thing apart to replace.I am wondering what made this do this in the first place & if I am able to reattach the hose as is would it hold.Nevertheless @ this point I need to find out what this part is.I am grateful for any & all help.