I suspect my block is leaking. What do you think if I take out the thermostat (mechanical one leading to the engine block) and do the pressure test after bleeding to find out if my block has leaks. Does this make any sense. The pressure test does not lead to anything now with the thermo in and I loose around a cup a day and see no leaks and pressure drop on hte test. I also blocked the heating matrix out of the circuit to ruel this option out. I am going to fry the engine if I keep on loosing the water. I will forget some day to top it off.