I own a 99 durango with a 5.2 with almost 103k. My heat is only luke warm. I changed the t-stat but no change.I also flushed the heater core and there doesn't seem to be any blockage. On the heater hoses under the hood the the one coming out by the t-stat is fairly warm but the one that goes back into the water pump is much cooler. Could this possibly be the water pump.
The water pump is a possibility, is there a vacuum operated control valve in one of the heater hoses? Will do a bit of research for ya and get back to you
January, 17, 2007 AT 10:13 PM
There doesn't seem to be anything, but all I can see is from where they come out of the firewall to the water pump and t stat.
January, 18, 2007 AT 4:00 AM
Have you bled the cooling system?
January, 18, 2007 AT 10:40 AM
When I refilled the coolant after changing the t-stat I ran the engine without the radiator cap and kept adding coolant as it went down. When it finally got to the top and stayed there I capped it off. Is that bleeding the system? I did notice that the temp gauge is only reading about 180 degrees and that you can stick your finger into the radiator after it has ran for about 15 min. But the temp outside was only about 20 degrees when I did this.I read in my do-it-yourself book about poor coolant circulation and to check this to pinch the radiator hose at normal operating temp and when you let go you should a rush going through the hose.I did not really feel to much when I did this.
January, 18, 2007 AT 10:51 AM
180 seems awful low to me. An oem tstat should give you 195+! Ensure yours is that! As for the bleeding, filling it cold and capping it won't suffice. I would fill it cold, leave it uncapped and run it till the tstat opens, then fill it more and then cap it (this way can be messy though!) They do make a " no-spill" funnel set up that works really well for this operation too! For cheap money! Second, you should be able to observe the flow thru the radiator as its running, you should really see the flow out of the core tubes (if you can see them) or see the flow of coolant across the top! If not, then the radiator my be clogged/corroded. Let us know!
January, 18, 2007 AT 11:06 AM
Where would I see the coolant flow from across the top?
January, 29, 2007 AT 7:57 PM
I ended up just changing the heater core. It was a pain but I've got warm heat now.
January, 30, 2007 AT 3:28 AM
Sorry I missed your earlier post! (Forgot to check the notify button!) Glad to hear you've got good heat now and let us know if we can help in the future!
February, 11, 2007 AT 7:09 PM
You said you replaced your heater core. Was it very difficult? I was not getting heat either, we replaced the thermostat and water pump and still no heat. So our next resort is the heater core. Please help.