Where does water pass to oil in Opel Corsa 1.2?

Hello everyone.
I just checked that water is happening to the oil in my car's engine. It has 200,000 kms. The water expanding vessel was empty. I am looking for possible causes. In principle I think it could be for the Board. However, the car had no warmth, a habitual cause of the joint.
How can I check where it happens? I would not like to lift the cylinder head. I have read that it can be for the Agua-Iceite exchanger, if it carries it. But I think the Corsa does not have it.
Any other place to go to? I repeat that it is water in the oil, not vice versa.
Thanks and greetings

Hi Maliayo, it is easy to be for the Board, although you say that it did not have Calenton (unless you know), but it may have happened to it if it happened ... to see if there is a new sleeve, the thermostat ... the radiator for some blow etc ... if it were the exchanger (which does not carry it) would be oil throughout the refrigeration circuit (for which I have seen). Raising the cylinder head to that engine is very simple, it is the best way to see if the Board is burned (surely) and take advantage of valve and tree seals, and find valves (it has kmts and would stay new). The water if it passes to the oil, this is "with cream" that is said and degraded, it can also be that it is only consumed by going to the combustion camera (through the joint) and another possibility is that you have a fissure in the butt and mix there. It looks like the Board. Greetings!