I have a real puzzel on my hands. I am losing coolant and I cant find were it is leaking. I wasnt having any problems before replacing the belt tenchiner. There are no visable leaks but on a two hour drive the over flow bottle is empty. Maybe a preassure test I dont know. But with hood up and car running still see now leaks cheaking everywere I can see and even lloking at the block I no smoke either. Please help thanks for looking

 

def do a pressure test. and feel the carpet in the front pass floorboard..could be leaking heater core

 

try this:
let the car sit overnight. in the morning, open the hood and take off the radiator cap (not overflow). if the radiator is not full, fill it up. then, turn the car on with the cap still off. let it run till the level drops (whenever the thermostat opens/ when the cars at running temperature). fill it up to the top again. when it stops dropping, put the cap back on and fill the overflow tank if needed.
hope it helps.

 

Possible head gasket. You should check the oil condition and make sure its not all milky looking. Or see if your car is exhausting very white smoke.