I have a 2001 dodge 2500 5.9 magnum the heat blows cool air , the truck runs hot when driving when I stop let it sit at an idle it cools off . I have replaced water pump , thermostat, and checked hoses . I’m at a loss it pukes up coolant at the cap . It ran fine till I let it sit for a while and it got cold here popped out a couple of freeze plugs . I replaced them no problems there but now it runs hot and no heat . No water or coolant in oil . Where do I go from here ?

 

Sounds like your cooling system is not completely full and still has air pockets trapped in it. Also, make sure that you have installed a quality thermostat (like a Stant Superstat).

 

Is it spitting coolant while cold? If so, you've probably got a blown head gasket. Rent a block tester at the parts store.

 

That implies the coolant in the block froze, and likely cracked the block....... Not a good scene. Test for combustion gases in the coolant. Bet it's positive.