Not to get of the subject of leaking coolant but heater core is inside the heater box
maybe you are looking at the AC evap
start engine and place temp on hot
fan on and selector on defrost
if front windshield start to fog or have a oily mist on it suspect heater core
best is to have the system pressure tested and by doing that leaks should show easy
Jan 8, 2011 at 3:13 PM