Leaking heater core?

[baksa]

Hi guys,

lately i've been smelling something from ducts when I turn heating on, and my car is slowly loosing coolant from time to time. From what I've read here, it could be leaking heater core.
How could I exactly tell if it is so, and where my carpet should be wet if core is leaking?
Also how do you get to the heater core? From inside or from engine bay?
I should also tell that my engine is OK, there are no signs of water in oil and there is no white smoke from exhaust even on high RPM (so I hope it's not head gasket...).

If anyone worked on this please reply.

Thanks.