I have read other thread's about not getting heat in the Jeep, but none of them have the answers I was looking for, and my problem is a bit different. I had an xj before and the heat blowing out was hot enough to melt a binder my friend put on the dash so I know how the heat should feel in these things. My new xj though blows cooler/warm air. If i close all vents (turn the *** to off), wait two minutes, then turn it back on to defrosters I get the hot hot air to blow out that i was expecting, but it cools back down right away.

I think my problem is a clogged heater core. When i bought the jeep it needed a new head, and my mechanic said that the previous owner had put Steal Seal in it to try to fix it. So i think that some of that **** clogged up my heater core and the antifreeze is slowly going through it, making it blow cooler/lukewarm air instead of cycling through it fast and giving me good heat. I have flushed it out multiple times and it did get a little better, but not fully. I unhook both hoses going to the heater core, and blow on one, and it was extremely difficult to get it loose. When I did it spit out a lot of black sand-looking crap. I have also bought a flush-kit and put a hose into these two heater core hoses and that run for a while, then fill it back up with 50/50 antifreeze and it helps a little but only gets clogged again after not too long. I have done this process multiple times. So my question for you guys is; Do you think if I keep doing this I will get any better, or will I have to replace the heater core? And if you have any suggestions on what to do please let me hear them.

Thanks,
Tyler

 

Do you seem to be getting good volume thru the heater core when you're flushing it?

 

Always helps to know what year XJ we're talking about or did I miss that? Does your XJ have a heater control valve?.....they're known to be faulty. Have u measured the heater hose temps at the firewall with a infrared temp gun. In defrost mode, the a/c compressor is engaged and vent temp won't be as hot. Water pump must be in tip top shape to adequately flow enough hot coolant thru the long heater hoses and heater core. Continuing to flush the core is cheap and easy, might as well, because replacing the heater core ain't cheap or easy.

 

I had a blazer that was plugged up with dexcool that had turned into mud. I tried every flush on the market and none worked. Out of frustration I tried a 1/2 cup of Cascade dishwasher detergent and ran for 30 minutes....not only did it unclog the heater core it made the inside of the radiator look like new. I have used as a routine flush on my jeep with success.

 

The Jeep is a 2001.