Loss of heat is most likely a GATE problem either a lectric motor opens and closes the GATE or as in the square headlight model wranglers, vacuum opens and closes the GATE.
Unless you have been way negligent with that Jeep the core shouldn't be stopped up.
As for smell.. if you can smell it then you will have a Sevier loss of coolant, and a wet floor.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist