Windows fogging with heater running

[worldtriad]

I just got this 1987 Tempo and tried out the heater and discovered that after the car heats up to normal temp, the air coming out fogs up the windows and seems to contain moisture which is probably coolant. There's no leaking under the dash or on either passenger or driver's side floorboard that I can find. This model has AC and I've looked up how to change out the heater core, but does this sound like a heater core problem?

As far as I can tell there's no external leak while parked. Level in radiator overflow was empty on hot so I filled that up to line, but was waiting for car to completely cool to look inside the radiator. Would low radiator fluid levels cause this?

Is there anything else this could be? Now that it's winter, I'm not going to be thrilled to drive with the heat off! Changing out the heater core doesn't seem like too much of an expense, but I'm not much of a mechanic myself.

Thanks!

Heather

[ryan1979]

Originally Posted by worldtriad

I just got this 1987 Tempo and tried out the heater and discovered that after the car heats up to normal temp, the air coming out fogs up the windows and seems to contain moisture which is probably coolant. There's no leaking under the dash or on either passenger or driver's side floorboard that I can find. This model has AC and I've looked up how to change out the heater core, but does this sound like a heater core problem?

As far as I can tell there's no external leak while parked. Level in radiator overflow was empty on hot so I filled that up to line, but was waiting for car to completely cool to look inside the radiator. Would low radiator fluid levels cause this?

Is there anything else this could be? Now that it's winter, I'm not going to be thrilled to drive with the heat off! Changing out the heater core doesn't seem like too much of an expense, but I'm not much of a mechanic myself.

Thanks!

Heather

I think its your heater core. A quick check, bypass the heater core and see what happens. You can do this by disconecting the hoses then connecting them together...this will remove the heater core from the system and no coolent will pass through it.

Cheers!

[ryan1979]

To clarify (because you said your a novice mechanic - no offence intended). Disconnect the hoses from the enging and connect them together. I'm sure its the heater core.

Cheers

[worldtriad]

NO problem, and I just found out from the previous owner of a year or so that it did this for her as well, so this problem has been going on for awhile. I would have expected interior leakage but maybe that doesn't always happen, or it's about to happen.

Thanks!

Heather