whats wrong with this b6 tdi ?

[vw754]

a4 130 tdi coolant problems
car loses water checked usual...no leaks.
water bottle is empty,when i take the cap off coolant bottle,lots of pressure then the bottle starts to fill with water that already in the engine ???????????

 

[evomaster3000]

My guess u got an air lock somewhere, u probabily need to bleed the system (if aplickable)