Seat Inca consumes antifreeze

A relative has an Inca 1.9 diesel of the year 98 with 270,000 km
for some time the antifreeze is as if it was evaporated, it had to fill in the deposit every week (300-400km apox.), Now it is worse every day has to go down with bottles of water to be able to work with it.
The mechanic does not give it a solution, according to him, one day he changes a sleeve, another that if a pore in the deposit ... In the end he says that it is old,
the case is that he does waters
, what do you tell me?

If you consume antifreeze begins by checking:
antifreeze pump (or water pump) that is not bouncing anticogellant by Ahy.
Fix if steam comes out at the exhaust outlet.
Check the hoses and their connections in case there are filtration.
Check the radiator in case it is broken and the lid of it.
The water seals (in this case antifreeze)
and finally if nothing bad is found in the above you have the last option that would be to check the button packing may be broken .. Note If you see water vapor coming out through the exhaust excessively you definitely have the badly blank packaging and you should change it ... luck

The water or antifreeze does not disappear, it is always somewhere, if it does not fall to the ground then the motor oil has seen how it comes out, whether it is emulted or not, the water line that is not with oil, and checks and controls the amount of steam that is made by the exhaust when it is walking, if it is much it is a cylinder head if it goes down without being walking the engine is running away and you have to look for it.