Could a bad hose near the t-stat that allows bubbles to enter the cooling system screw with a t-stat's ability to function properly? I have done much trubleshooting yet, but I think I have a bad hose since I've been finding coolant next to my water pump. I my fan controller has been actinig screwy, I'm thinking that the t-stat isn't opening due to air in the system. I just put another new t-stat in with the same results.