I already texted a couple of people on here for opinions, but unfortunately I discovered last night that the head to my BMW 318 (M42B18 - 1.8L 16v 4-cyl) is cracked at the #3 cylinder by one of the intake valves and a waterjacket. The headgasket LOOKED to be alright, which the crack would explain why the cooling system was pressurizing and overheating without much in the way of steam out of the exhaust.
I've already dropped it off with Mike @ M&M Head Service in Delaware who rebuilt the 300ci inline-6 in my Ford F100 a few years ago. He said they would disassemble the head and clean the parts/valves, then his cast aluminum welder will look at what it takes to repair the crack. Provided it can be properly welded (grind, weld, oven bake to cool down the head properly), they will machine the head and reinstall everything. Range for entire R&R and repair is $300-$500.
I've gotten guarded responses from people, and I'm certainly aware this can be a risky repair though I do have faith that if someone can fix it, it's M&M. Anyone gone through this process before?