New to the forum but a long time jeep owner. One of my current Jeeps is a 2013 Unlimited Sahara and has me scratching my head. No issues until recently, so the notorious P0306 code started showing up along with it running hot and not blowing hot air out the vents. Flush the system 3 times, changed the thermostat, water pump, even had the dealer flush the system. Heat blows hot then Luke warm, cold, back to warm. Dealer said my jeep was not covered on the 10/150000 extended warranty due to its VIN. No leaks, blend door, actuators all working fine. Has anyone else had this issue, please help. I also contacted Jeep, basically was told there was nothing they could do.

 

Just a possibility that you may want to research: Cracked cylinder head. That could cause overheating as hot engine gases are pushed into the coolant system. Coolant can leak out through the engine and be blown out the tailpipe. Low coolant in the system can cause sporadic passenger compartment heating issues, as well as exacerbate engine overheating. And certain 3.6L motors were prone to this problem on their left cylinder head. Don't worry about cost; you should be covered in their unannounced warranty if it turns out to be true ...

https://www.autoevolution.com/news/p...ure-82615.html

 

Just a wild guess, but it sounds similar to problems I had. The dealer "burped" the system by parking it facing up an incline - and opening the radiator cap. The idea is that air is trapped in, I guess, the heat exchanger. Anyway, it's worked a couple of times when the heat seemed weak for no reason.