What makes the heat not getting hot enough in a 1993 blazer?

Answer 1

Over time the coolant system can build up from minerals in the coolant, this in turn can cause blockages or thinner walls within the coolant lines. The lines are primarily aluminum within the radiator and heater core which can corrode adding to the problem. When this happens not as much coolant is flowing throught the heater core and therefore not as much heat blows out the heater. Worse case scenerio is that the heater core is blocked so bad that you may need to replace it. Best case scenerio is that you need to buy a coolant system flush kit and follow the directions to flush out the system. another scenerio is that thermostat is not opening up enough to let the maximum amount of coolant to pass through. I would recommend that if the vehicle is running hotter than normal, then you may need to change the thermostat.