Weird Smoke out of Vents

[94renegade]

ive got 94 YJ and in the morning i get some smoke coming out of my vents on top of the dash... this happens when the fan is off and when i turn it on, it blows smoke for a bit then it seems to get it all out of the system and its fine... the problem is it leaves a foggy film on all my windows and i have to clean the inside of my windows every morning. This started about a week ago. I dont have A/C either. Any thoughts? Thanks.

[fredjacksonsan]

Sounds like a leak in the heater core, it's letting some coolant into the cabin. Try routing the hose from the water pump right back to the water pump; if this solves the problem you're looking at a new heater core.