cozza

I've been having a issue with coolant loss on the 1.6tdi 2015 occy ive had it about 2-3 months. The water slowly drops around 200-500 miles i get the check coolant error, i check under the bonnet and its either low or almost 1cm from the bottom (its always checked when cold when possible) So after a few errors i contacted skoda they booked me in for a pressure test he said it could be the water pump he fitted it but stil no joy.. i called again the techs kept saying it might be a air lock etc.and that the expansion tank will naturaly move with the pressure when the cars hot as the coolant moves to the radiator, So i gave it a few more weeks as i was moving house. I then called again they booked me in they had my car for two days they said a tech and master tech spent hours going over it with a fine tooth comb the couldnt find a leak on the hoses radiator egr cooler etc and that he thinks the expansion tank cap could be moving under high load so they replaced the cap and expansion tank. I drove it just over 200 miles and its stil come up check coolant i looked under the tank was 1cm from the bottom again so i added more water. I've called them up again hes told me hes basically out of ideas, as he said you would see the antifreeze from the leak hes assured me it cant be the head as hes checked but we are stumped where its going and why its not showing a leak on the road or hoses etc. So i basically said i'd try some k-seal would it affect my water pump bla bla he said its fine and a good idea to try it so i kind of at a guess will have to wait until a part breaks before i can fix it. Feeling very disheartened on a now 19k miles car im stumped. I drive it around 500 miles a week as its a taxi but im topping it up almost every other day a long run like say 180miles it looses around 2" of water from the expasion tank other then that im checking daily..and topping up as needed. Carrying my trusty water bottle.