i have an audi 100 cs 2.8 L. I've been experiencing coolant leaks since i bought it some year ago. First i noticed expansion tank was in bad shape so i replaced it. Seemed to stop the problem for the most part. Now coolant is leaking all over my floor inside the car! Leading to think its heater core, but im not very familiar with cars and not sure if it would be this seeing as i can still get good heat from vents. Also, cannot defrost car- i think this would be because of antifreeze in the air?

Wondering if anyone has some tips before i look into getting it fixed, maybe save some moeny on labour if i nail the problem before.

It is the heater core. Either that or the lines connecting to the heater core are leaking. Either way it can be a little difficult to fix. I would check the lines first of coarse.

Welcome to the world of wet sucks and frezing winters aka Heater core is bed