Hi I have a 2013 Chrysler 300 c 5.6 L V6 around 88 thousand miles. My thermostat had a crack in it and was replaced at a shop and I had no coolant. Well 4 weeks later and I was out of coolant again and brought it to another shop. No leaks found but I was missing over a half gallon of coolant. Fast forward to now 3 weeks later and no coolant again. I took it to a Chrysler dealership this time and they found nothing even with another pressure test but coolant was missing again. Any thoughts on what this could possibly be because I’m at a loss for words. I’m not mechanically inclined and if the pros are saying they can’t find the problem I don’t know any more. Any help is greatly appreciated or any suggestions. Thanks