I have a Mazda Millenia 2.3l SC S model with the Miller Cycle Engine.. I have recently put in a brand new thermostat.... My car is still overheating... I can see that the radiator looks bad there is a hessing sound coming out by the upper rad hose but not a leak more like a fine line crack but hessing.... I know the radiator is bad and needs to be change and I am doind that ASAP, but I also know the radiator is still pushing and holding coolant...Could it be the water pump???? I put my scan tool on it to see if any coolant codes come up and none do.... What is the problem....

Thanks
James