I am right there with you on the salt destroying the car!! I bought mine in NC now in NY and it pains me to drive it in winter here! Usually I am away in winter and it sits but not the past few years. Amazing how much damage salt does! If I had another vehicle I would use that too. So you must have a lot in their clogging it up. When you said there was sloshing sounds i thought maybe just getting the air out might work (like with mine). I just ripped mine apart a few days ago to replace crossover gaskets (posted in another thread) avoided it for months lol!!

 

Yea, the sloshing sound.. Thats been there for years and I used to have heat with it. Im slowly starting to remember times of needing heat (when it wasnt cold, usually cooler summer nights) and it didnt work well but I just didnt realize at the time.

That crossover gasket must be a headache. Id be getting the welder out and be making a terrible mistake by now, LOL.

 

So I just remembered another thing I do for getting air out of the system... I just keep the rad cap off and let it idle a while until the bubbles go away (or when it starts overflowing). Not sure if you already tried that.

No welders for me yet lol Its a coolant crossover pipe on the 3500 they changed the design the next year and for those of us with this design i guess we just buy lots of gaskets! Took me most of the day to take it apart then a good part of the following day to put it back together.

 

So ill update this seeing as I have fixed it. WAS the heater core.