Hi. I have a 2013 skoda vrs 2.0tdi. With 83 thousand miles. Full history. It looses water every two weeks. Maybe half a litre. So I’ve got the timing belt and water pump changed and still the same. No visible leaks anywhere. Are these cars given to head gasket problems. I opened the bonnet one evening and could see a trace of water around the expansion bottle. Any help would be great 

Locate that leak then and fix it. 

If that is where there is a leak in a pressurised system.

 

The Water Pump is the usual cause of the leak but seeing as done and if done properly then you need to check the expansion bottle and the pipes / clips.

Are these cars given to head gasket problems 

Not one of their common faults.

Check out the simple stuff before having someone pressure test the car for you, 

like the person that did the water pump could have.

After having the original water-pump fail within my 2014 VRS, it’s replacement failed just a week after fitting. Is it possible you had one duff pump replaced with another?