Heater Core/Valve Leak

[Van Westervelt]

Same, seal or the core. If you like skin on your ankles, I'd stop driving it until its fixed.

[jlevie]

If you have coolant appearing on the floor mat, the heater core or the o-rings that connect it to the pipes that penetrate the firewall have failed. As a guess I'd say that it will be a failed heater core.

I'd say that the coolant on the mat is already a big problem and I would not drive the car until the leak is eliminated by replacing the core or plugging the heater hoses.

[OttoBob]

Can anyone give me an idea of how to determine what is leaking and how hard the repair is? I have some coolant appearing on the rubber floor mat on the drivers side of my 1989 325iX. The heat works great, but my coolant level in the expansion tank has been declining slowly. How fast will this become a big problem?