Ok so I have not used the heater until yesterday flipped it on and got a smell of antifreeze. so I switched it off. drove home no smell no overheating it sat overnight and i noticed a small pool of antifreeze (about 1-2 cups) under the truck I also have antifreeze in the valley under the intake manifold. I checked the 2 lines going in 1 looked loose but has no water coming out the other had a few drops on it. cranked it up today and the temp went up fast. i popped the hood to take a look and with the engine running i didn't see anything leaking but i did see a small amount of antifreeze on the center hump on the passenger's side. so core blown? why did it not do this with the heat off doest the fluid still get pumped through it? I also noticed that both lines had regular screw band clamps on it. does anyone have the part # of these spring loaded clamps? would that cause a small leak in the cab? it gets close to overheating in about 35-40 min running but doesn't overheat yet. but the fluid is a bit low.

 

is your intake manifold plastic if so check for water or antifreeze coming out around the cross over hose under the intake.or the line under the intake. leaking in floor sounds like a leaking heater core.