I don't know WTF is up with my heater. Ever since I bought the car last February, it hasn't been working. What are the problems associated with the heater core and how can I fix them?

The heater blows COLD 100% of the time: A/C, defroster/ AND heater.

I haven't tried flushing it, but what else can be wrong.

 

Have you tried flushing out the heater core hoses and core directly? Also, make sure that you car still has the thermostat in it.

 

Hey, i had a simmilar problem with my car. Pull the heater hoses off the heater core up at the fire wall. Back flush the heater core, both ways. When i did that I got a ton of crap out of the heater core. I put it all back together and had all sorts of heat....it would bake me out of the car. Also check for a thermostat in it. I run 180 degree..and it runs cool in summer and winter. Good luck

 

If your coolant is red it is dexcool. It has most likely clogged the heater core. Does it sound like you have water rolling around in your dash? If so back flush the heater core and block and go with good old green antifreeze. Your problems will go away. Also install a 160 tstat and that help
HVY SS

 

hey i had the extact same problem since i got my car on monday. well i searched around and found this: fixing cold heat
i would recommend 2 people for the task...i did it in my autoshop class with a friend, the idea of the job is simple...pulling 2 hoses out of the firewall and flushing water through both metal pipes they connected to in the firewall...but the clamps are a pain to take off and also reattach. but overall its not that bad and my heater is HOT now!! good luck.

 

The problem is corrosion inside the engine sluffing off and clogging the heater core. If you don't get most of the corrosion out of the block the problem will return like mine did. you should use a flush in the block before you flush the core. When you do flush the core, take the hoses off at the pump not the core. This way you can clean the hoses and the restrictor that is inline to one of the heater core hoses. The restrictor is black plastic. While your there, check the crimps at the restrictor, they leak often. Easy to fix without replacing if they are leaking. Be sure to use distilled water when cutting the antfreeze 50/50. Tap water causes corrosion.