Stalling rough idle

Have went through replacing various crank sensor, cam sensor, idle air control, pcv, fuel pump, changed the fuel nothing solved this issue. Finally found the problem which didn't present itself like other problems in some other cars. Noticed that the coolant wasn't flowing through the radiator hose despite changing the thermostat and the water pump Back pressure was on the coolant through the radiator, which also had a mixture of coolant and transmission fluid. Diagnosis, blown head gasket!! The car was stalling and rough idling because of this. Would run great after cooling down. But would stall. After warming up So check out this problem if all other suggestions fail.