Ive been having problems with the truck not blowing hot air. I flushed and back flushed the heater core. No fix. I was then told to put a piece of carboard in front of theradiator to see if it is the thermostat. I did that and the air didnt get much warmer but the temp went up almost in the red. What gives? Is this a thermostat issue? Thanks!

 

What engine?

Some engines require you to bleed the coolant system. Not sure if the Dak has that? If it does there would be a bleeder screw in the top radiator hose or near the T-Stat housing. Just open, with the heat on, engine running, engine hotand let it bleed until it primarily shoots coolant.

 

Its a Deffinate possibility and inexpensive and probably your problem so i would change it, but thats me.

 

so does anyone know if the 3.9 6 cly dakota has a bleeder. i have the same problem. flushed the core three times. opened the radiator cap and ran that open. still only get good heat at 2000 rpm. any other truck ive had that tells me air in the system some where. I was asking my machanic and he said it had to be air but it would work its way out. that was a long time ago. changed the stat twice. richie

 

try this. let the truck idle and grab the lower radfiator hose, if it is not hot then the radiator is on the way out. if it is hot then the stat is shot. the newer stats are failsafe. if they go they open up. unlike the old ones which closed up.

 

a t-stat is cheap enough if you know how to replace it. drain the radiator, replace the t-stat, fill the radiator with coolant and run the motor for at least 5-10 minutes with the cap off. Squeeze the top and bottom hoses to work out any air bubbles and top off fluid as needed. You might check your heater core for leaks as well.

 

Thanks for the responses. I will give them a try. It is cheap enough I can just swap it out. However, I did take it out and put it in a pot of boiling water and it opened right up. Does this lead you to believe it may be the radiator???? Thanks!!