Does this always = Heater core? I don't see any puddles on the ground of anti-freeze, and no puddles inside on the passenger side floor... also no white smoke out of the tail pipe. it still runs with full power and idles smoothly? I do get a few rattles from the motor when i am going up hill slowly in a lower gear... I use full-synthetic motor oil just to be safe, but I am not very experienced and don't know where this anti-freeze smell is comming from.

 

Welcome to DF! Moving to the correct section.

 

Do you smell from only in the cab, only outside, or both?

 

foggy windows when u turn on defrost?

 

Here is a picture of the heater core from my old 1997 Ram. Note the pinholes, which explains the odor of coolant in the cab at all times, yet no indication of visible leaking ever existed.