Had it been sitting when you bought it?
I'd suggest you flush the cooling system AND change the oil. Reassemble everything and see what's what. Without good history on the vehicle, the only thing you can do is start from a good known state with the fluids and see if you get cross contamination and/or overheating.
It's certainly not a good sign, but you never know. __________________
SOLD!!! 1999 332ti //M Sport Titanium Silver
M3 S52 3.2 I-6 Engine, M3 Clutch w/ ti Getrag Trans, Z3 3.15 LSD medium case diff and half shafts, OEM Hatch Spoiler, Eurosport HP Underdrive Pulleys, FDM, 17" DS1 rims, M3 Front Struts & Springs, M3 Instrument Cluster, 3-spoke //M steering wheel with tri-color stitching, SSK, CCFL Angels in Depo projectors with 5k HIDs | 
Hybrid Mode
