So on an 04 Dakota SLT 4.7 my friend has it has a smell the coolant smell inside the cab like would be normal for a heater core leak. However, the floor has never been wet with coolant and the level doesn't go low. It appears but can't verify the dash has been removed at some point but don't know what for. I did the heater core myself on my 99 Dakota R/T and it was actually leaking on the floor. My friend even pressure tested his cooling system but couldn't find any leaks coming from the heater box. I notice it has a different heater core than my 99. It uses separate metal tubes with o-rings. It appears that the dash still has to be removed similar to how it was on my 99. But before doing that is there anything else that should be checked before suspecting a heater core leaking? For the summer he bypassed the hose but not it's starting to get cold. He's wondering if something could be up with the heater core tubes, maybe an o-ring failure. Can you remove the tubes through the engine bay without taking the whole evaporator box out?

 

When you smell the coolant... is the air of recirculation or vent or both?

 

It had the coolant smell coming from the vents even with the A/C on. I don't remember but I'm sure it was in recirc mode. Don't know if he ever uses the a/c in vent mode. Never found any wetness on the carpet or under the carpet. Never any coolant loss. He bypassed it for the summer but now it's time to do something about it as it's getting colder. But would hate to do all the work if it could be something else. I remember doing it on my 99 and it took a couple days but I took my time. I also had to replace the evaporator box because someone who had done it before didn't do it right and broke the box.