I just bought a 96 jeep loredo 4.0 that was overheating. it doesn't lose ANY coolant, at all, but still overheats every 3 miles and starts to lose a lot of power and stall. OBDII scan revealed Code P1391 and the code for the speed sensor. Oil looks clean and free of coolant. coolant looks clean and stays at the same level inside the radiator. when i squeeze the hoses when its hot they're still soft with no pressure buildup. before it stalls it starts to hesitate and tap. (i quickly called a tow truck) what could be causing these problems? What else should i do? (i bought the speed sensor and a thermostat... too cold to install right now)