Last winter I tackled replacing the front heater core. Replaced the blend door and blend door motor while it was apart. Before the repair, I had really hot heat in the rear and none in the front. Now I have really hot heat in the front but the rear is luke warm. Will get a bit hotter after 30 minutes or so of driving but not close to the front of the amount of heat I had before replacing the front core. I am sure it will feel colder and colder creating complaints from the little ones in the rear as the weather turns. I also have the constant smell of antifreeze at the grill but cannot find any leaks and am not losing coolant. Have the same smell in a 1995 ford ranger.

Any ideas?