I have a 99 Durango, 4x4, 5.9l 140k miles. Runs like a trooper, have had no real issues (knock on wood) except this summer the ac went out and now this winter it doesn't heat up worth a crap. I can leave the heater running non stop and it will never really gets much more than luke warm and that's on 20 degree day. This is not my daily driver so I have been putting up with it for now but with finally having a real winter some heat would be nice. Any ideas? I had the heater core replaced a couple of years ago so hoping it is not that. Hoping for something simple, like thermostat bad or switching back to 210 thermostat from 190. Fluid levels are fine and haven't noticed any leaking anywhere. Taking it to a garage I trust but always like to get some wisdom from the group 1st.

 

Yeah, got to love our 99 D's. Most fun un-heated bastards. Cant dial in so i'll toss up some questions/solutions- Hows your lines at the firewall for the core feel? Both about the same temp? Have you tried removing the lines (One at pump/ other @ splitter ontop/by left valve cover) and flushing the system with a garden hose from each line until it runs clear? Do you know about the temp control cable? Just an insight here is a link to take a gander http://durangoclub.com/forum/viewtop...p+adjast#86225

 

I have 1998 model i can trun the heat on but it does not get hot in side but if i turn the switch on 2nd cycle it gets warmer but does not get hot inside so what can i do so the inside gets hot thanks

 

i had the same problem no heat. you probably need to flush your heater core and wather pump its easy i did it in under 40 minutes and now i have hot hot air. here is a link with pics and a step by step https://dodgeforum.com/m_690541/tm.htm

 

This operation dose not flush the water pump. Only the heater core.
Second, You want to run a 180 degree T-stat for the 5.9L motor because of head cracking issues. OEM is 195. Now running the 195 is not recommended. It was installed OEM for emisions.DO NOT put a 210 in!

Other possible issues could be the T-stat neck could need to be replaced. $8 at the dealer. If this is your problem, clean the intake manifold and add small bit of silicone in between the T-stat and manifold.Thensilicone then gasket then siliconeand finally install thenew neck. The problem is the manifold is aluminum and the neck is steel so after time the manifold pit's and the steel neck rots creating flow around the T-stat.

A lot of time and money went into this problem for me.

 

check radiator cap to se if it holds preasure my did the same and new cap fix it

 

The 180 degree thermostat seems too low to me. Even in our mild Mississippi climate, the air never really gets hot now that I have a 180 degree thermostat in.

 

Another recommendation. If indeed a flush on the heater core resolved your problem, and you have already changed out the heater core previously. These are tell tale signs that you have serious cooling problems on your Durango. You may need to have everything inspected from fluids, radiator, pump, etc.

 

I get prety toasty air in my 5.2 in cold weather. plus I feel more safe with colder engine temps

 

I freeze my *** off but I don't care because of the longevity that will come from the motor.

Also I need a new heater core but I don't want to break down the dash. I'll wait for now.