Hey Scotty,
I have a 2002 Dodge Ram 1500 5.9L gas with about 145,000 miles. It goes through coolant and I can't figure out why. I used leak die and found nothing. I also used and head gasket test kit on the radiator and it was fine. Yet, the coolant disappears. When driven to town and back, I get out and walk around the front and can smell coolant, not heavy but it's there. Not sure what to do next. Thanks in advance, you're awesome.
It's either leaking or burning. There are no other choices, the coolant isn't disappearing into the Twilight Zone. You could try pressure testing the cooling system. You could have a heater core leak which would not be easily visible. (That would be no surprise after 23 years.) Also, the common head gasket test does not detect all types of head gasket failure.
A bad radiator cap will cause this, pressure test the cooling system.
