Overheating, no heat (new parts thrown at it)

[5zero6]

2015 jku 3.6
Two nights ago it started overheating sitting in line at a fast food restaurant….. called mechanic friend, he tells me for sure it’s the water pump….

Buy new water pump, install, flush coolant…. Same issue. Previously I could get heat to work.

Thermostat was replaced 2 months ago, it failed the boiling water test, so I’ve replaced it too….. put more coolant in. I feel like I have ALOT of coolant in there, but I just keep adding more, and don’t appear to leak, other than losing a little trying to burp it.

No heat at all… over heats as soon as I get in the road… it’s currently 40°F outside

I also encountered a strange issue eairler, I turned the heat on, and my rear defrost started blinking for a minute or two, and finally started. I didn’t read too much into it, but evidently it’s something with the doors for the vents?

Do I just keep adding coolant until I can’t add any more, I’ve tried to let air out through the thermostat and tried to let it bubble up.

 

[BLACKJKU]

Try raising the front of the Jeep up about 6" with the cap off and engine idling, most of the time that works the best to get the air out.

 

[TROY66/68]

Overheating? That is my wife, just sent her back out to shovel, saving the gas for the Generator, constant grid failures now. (no Snow Blower) need fuel to keep the Home Brew cold. Ya Ya , put the beer on the poach. All Good

 

[AUBoggs]

2015 jku 3.6
Two nights ago it started overheating sitting in line at a fast food restaurant….. called mechanic friend, he tells me for sure it’s the water pump….

Buy new water pump, install, flush coolant…. Same issue. Previously I could get heat to work.

Thermostat was replaced 2 months ago, it failed the boiling water test, so I’ve replaced it too….. put more coolant in. I feel like I have ALOT of coolant in there, but I just keep adding more, and don’t appear to leak, other than losing a little trying to burp it.

No heat at all… over heats as soon as I get in the road… it’s currently 40°F outside

I also encountered a strange issue eairler, I turned the heat on, and my rear defrost started blinking for a minute or two, and finally started. I didn’t read too much into it, but evidently it’s something with the doors for the vents?

Do I just keep adding coolant until I can’t add any more, I’ve tried to let air out through the thermostat and tried to let it bubble up.

I would perform a block test to rule out head gasket and/or an issue with the heads before throwing any additional parts at it. I had a similar issue not being able to purge all of the air and, ended up being warped heads.

The blinking light for the rear defroster occurs at start-up, I assume? You should be able to hear all of the actuator doors opening and closing while it blinks. It could be the AC actuator door has failed which opens to allow the system to blow hot air into the cab. There is a good step by step instructional post in the "How to" section on replacing the actuator. I just replaced mine a week ago, and have heat again.

Hope this helps.

 

[Anybodyhome]

Two nights ago it started overheating sitting in line at a fast food restaurant….. called mechanic friend, he tells me for sure it’s the water pump….

Buy new water pump, install, flush coolant…. Same issue. Previously I could get heat to work.

Thermostat was replaced 2 months ago, it failed the boiling water test, so I’ve replaced it too….. put more coolant in. I feel like I have ALOT of coolant in there, but I just keep adding more, and don’t appear to leak, other than losing a little trying to burp it.

Is it going straight to an overheat situation or is the temp gauge kind of bouncing all over the place? If the temp gauge needle is moving around a bit, that would suggest air in the system.

Cold start the vehicle and wrap your hand around the upper radiator hose. If you don't feel the coolant beginning to flow thru the hose at around 180-205 degrees, the t-stat is stuck closed.

Those 2 quick checks will eliminate 2 of the simpler fixes.