So i tried utilizing a couple folks I work with but they seem stumped. My heater blows great heat as long as i am driving above 35MPH. If I slow down or come to a stop it's back to frigid air. Any thoughts? A google search was also less than helpful

 

What happens if the JK is sitting still, in neutral, but you have the engine revved up to about 2,000 rpm?

 

I will have to try at lunch or after work. Unfortunately this was noticed on my drive in this morning. I read about a similar issue on a sister forum after posting this that it could be air getting into the heating system?

-edit- Coincidentally you were the first reply on that thread as well!

 

Have you checked the coolant level? Low coolant levels will effect the heating, less or no water flowing through the heater core.

 

Took it to AutoZone and was confirmed that I am kinda dumb and screwed up a lot last time I changed my thermostat. Despite it having its own rubber gasket, the clerk when I bought it told me I needed to apply some blue sealant as well, so I did. I also did not have the system running at temp when I filled it back up and did not "burp" it? So I guess it took about a year or so for it to decide I done screwed up.

Last night I replaced the rubber gasket for good measure, scraped off the old sealant, got everything together, re-filled, and tried to burp it to the best of my understanding... so far it seems to be working okay this morning?

 

I just replaced my thermostat this past weekend, I did place a thin bead of high temp RTV. Getting the air is important, there is a special funnel that can used to assist in this process. I did a few heat up (thermostat opening) and cool down cycles, adding coolant after each cool down cycle. Check the coolant level again after driving, add as needed.

 

I think I may actually have a small leak from my overflow as well but won't have time to check it out WELL until this weekend. But the floor of my garage seems to that familiar slippery green spot where I park