hi i'm new here so hears the thing i have a 1999 Durango 5.9 and the motor wont get above 135 when the temp is below 50 but worms up nicely when temp is 50+ with this problem i have 0-little heat when temp is under 50 and excellent heat when temp is 50+. so far i have replaced t-stat back flushed the heater core back flushed the radiator and flushed out the motor as well. am i missing any thing looking for ideas on this thanks

 

Fan clutch stuck?

 

fan clutch seems to be working just fine

 

What brand thermostat. The engine should get up to temp regardless of outdoor temp.

 

duralast 180 degree

 

Buy a better thermostat. Stant is good.

 

I have a stant 180 and a stant 195. I just put the 195 in until about May when I'll switch back to the 180. I get warm air with the 180. I get hot air with the 195, which is the factory temperature. So it might not hurt to go to one of those.

 

Get your heater core blasted, I had the same problem and this got me back to cookin

 

Sounds like thermostat.