My daughter has a 2004 r50 mini, which keeps on overheating. I have changed the rad, cooling fan, pump, temp sensor, pressure cap, & 2 x thermostats. I bleed the system through all 3 bleed screws, & the heater blows hot. But after a run the engine has pushed coolant into the header tank, above the max mark. As the car cools it does not draw the coolant back into the system. Eventually after a few runs, it will overheat & put the warning light on. There is no evidence of oil/water contamination. Cylinder compression 1=15bar, 2=17 bar, 3=17 bar, 4=16.5 bar. Pressure tested the rad at 1.1 bar & left overnight, the loss was negligible.
I have run out of ideas, help!
