itsmee2021 Posted December 14, 2020 Report Share Posted December 14, 2020 I am having problems with my 2010 DJ heater. My heater core needed replacing so got that done. Had some heat after that not much so put in a new thermostat. Now I have lots of heat. The problem is as soon as I get up to highway speeds the heater goes from hot to lukewarm. This happens on both the passenger and driver side. If I slow down or stop the heater starts pumping out hot air again. Any suggestions? Quote Link to comment Share on other sites More sharing options...
5rebel9 Posted December 14, 2020 Report Share Posted December 14, 2020 What size motor in it and how many miles on it? Could be anything from a bad rad cap or a coolant leak that is allowing air entrapment, which can cause the symptoms you describe. Quote Link to comment Share on other sites More sharing options...
2late4u Posted December 14, 2020 Report Share Posted December 14, 2020 tale it back and have the coolant system bleed it of air again Quote Link to comment Share on other sites More sharing options...
itsmee2021 Posted December 17, 2020 Author Report Share Posted December 17, 2020 It's a 5.2L and has 183000 kms. How would I go about bleeding the system. Also anyone know how to access the blender door by the glove box? I was told it could be stuck as well. Oh it has a new radiator cap as well. Quote Link to comment Share on other sites More sharing options...
2late4u Posted December 17, 2020 Report Share Posted December 17, 2020 (edited) 5.2 ? I assume that you mean a 2.4 engine, not sure but doesn't it have 2 thermostats , hope someone comments on how many there are.....you tube has a lot of good info and videos on how to check the doors, easier to watch then explain Edited December 17, 2020 by 2late4u Quote Link to comment Share on other sites More sharing options...
itsmee2021 Posted December 17, 2020 Author Report Share Posted December 17, 2020 Sorry I meant a 3.5L. All actuators and blend doors are working so they aren’t the problem. Quote Link to comment Share on other sites More sharing options...
itsmee2021 Posted December 17, 2020 Author Report Share Posted December 17, 2020 I believe it only has one thermostat. Quote Link to comment Share on other sites More sharing options...
itsmee2021 Posted December 17, 2020 Author Report Share Posted December 17, 2020 Checked coolant temp. Went up to just over 200F. Anyone know what temp the fan is supposed to kick in at? Mine kicked in around 190F. Quote Link to comment Share on other sites More sharing options...
probak118 Posted January 10, 2021 Report Share Posted January 10, 2021 (edited) https://www.classaction.org/jeep-wrangler-air-conditioning-heater-lawsuits After trying different things plus, confirming the operation of all duct door and actuator motors in my 2012 DJ I was stumped. I even checked the temperatures of the heater core inlet and outlet hoses, although not the same they were within 10 - 20 f of each other it appeared. I had already had the heater core and coolant changed three years ago. So I went and talked to a friend who works at the tech help centre at one of the big 3. He knew immediately what the issue probably is, casting sand from the motor cylinder from the manufacturing process is breaking away and plugging part of the heater core. The bottom part which just so happens to direct heat to the passenger side of the cabin. honestly I have never heard of the this issue, but am told is affects all first generation 3.6 L Penstar motors. He said, the dealer when having to replace a heater core will try to do an aggressive extended flush to try and remove as much of this residual sand as possible then install the new heater core. But does not get all the sand out, it will eventually happen again. One thing to inspect is the coolant resevoir bottle for a thin sludge type layer forming on the inside of the bottle, that is a giveaway that the fine sand is now moving around the coolant. Sorry if I am beating a dead horse, but this was news to me. I stumbled across this link above when I googled casting sand plugging heater core, information on a class action for us dodge owners, it seems the jeep wrangler owners already won some sort of settlement. If nothing else I now know probably what the reason for my no heat on passenger side, but the fix is keep changing heater core.....BS ! Edited January 10, 2021 by probak118 2late4u 1 Quote Link to comment Share on other sites More sharing options...
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