Hey guys please help if you can, 93 5.2 magnum.(Heater core bypass during all the testing) With a radiator pressure gauge I hold 16psi with no drop. Cap tested and pass also.. 2nd water pump in a week I can take heater hose off while running and it pumps water out fine, I can pinch the heater hose and it doesn't affect the top return hose to radiator pressure wise.. block flshed through block drains thermostat opens and trickles out enough to get top tank of radiator hot.. cap on and I don't build pressure and starts to over heat. Would cracked heads do this or can someone please point me in the right direction.. it built pressure one time during testing just long enough to cut truck off, crunk it up and it was gone again

Last edited by Bama ram; 11/11/18 06:23 PM.