99 Dakota heater issue...

I own a 99 dodge dakot 5.2 4x4 and I am having an issue with my heat. When the truck is idling, it blows out luke warm air even when the truck is at temp. But when I increase the idle, the heat temp instantly increases... is this normal or what is possibly the problem. I have flushed the heater core twice in the last month and both times seemed to have helpd but not totally fix the issue. I have also been burping the system of the last few days to make sure there is no air in the system. :banghead::banghead::banghead::banghead::banghead:

Thanks!!

check your thermostat, make sure it's the proper heat range, factory recommends 192 F thermostats but there are some as low as 160.

I replaced my thermostat to a 192, and am still having the mediocre heat.... any help is greatly appreciated!!!

sad to say, you're going to need a new heater core. I know I need to replace mine on my '95 Dakota V6, it's doing the exact same thing as your truck. Good thing is, it only costs $40 for the core, bad thing is you'll have to take the dash out & have to discharge your freon to replace it.

Hello, I had this issue with my wifes 03 Buick. I added antifreeze in the reservior and it fixed it, obviously not enough in the system, hope this helps.