I have a 1979 ford honey motorhome rv with a 351 w I have no heat I let it run with the cap off to let the air out.it's hoses are hot heater core hoses are hot, all spongey at this point it seems a little heat is coming out but not a lot,I start to drive it and the guage will not move off c line the hoses are now had. I have put a new thourmastatin 195