Since about two (2) days I have completely fogged windows while driving, making it really difficult to see and almost dangerous to drive. I could not figure out what it is, playing with the temperature dial on hot and cold as well as directing the airflow to window or not. What I am also noticing is that it seems like I have mist coming out of my air vents. I now believe that the system pushes moist air into my cabin and I am suspecting a pin hole leak in my heater core under the dash where coolant escapes and makes the air moist only. I have not noticed any noticeable loss of coolant, however I believe it is going down.
Anybody had something similar happening? Am I right to assume that I will have to pull the dash out in order to change the heater core? Also, when I operate the temperature dial, I am actually changing only how much air runs over the heater coils and not how much coolant flows through them, correct? I am thinking also to just proof my theory, that I could clamp the hose going into the heater shut right before the firewall to see if it changes anything. Should I be ok to do that? As far as I know the system does not rely on that flow through the heater to keep circulating.
Any advice is greatly appreciated.
Thanks in advance. Axel