Hi Guys,
I just got a new Jeep JK (2011) and its my 2nd Jeep (WHOOP!!) I Owned a 90 XJ previously as an off roader project fun machine. Anyway, this JK seems to be running hot? Here is a pic of where my temp gauge seems to be hanging out recently. It will get up here if your driving it with AC on. Otherwise some light in town will keep it in the center with no AC. Radiator looks OK, see some leaking from cap area which they replaced recently near cap and upper hose. Pressure tested OK, noticed it was at Min coolant levels when I picked it up, they topped it off and now its about 1/2 way in-between the min and max on the overflow bottle (maybe boiling over and getting out overflow bottle). Really checked around the water pump area and hoses, nothing seamed to be leaking around there. Once it gets up this hot, you can get it to climb back down only with the heater on or shutting it off to let it cool. Its a very strange intermittent cooling issue, seemingly triggered under load more than anything else (AC up hill, stop and go IDLE). Radiator cap improved it but as you can see, it still seams hot to me? How about you guys what do you think? Too hot or OK? Thanks

 

Hello Falcon, I live about ten miles south of Detroit in Canada, We are at about 500 feet above sea level and my Jeep never gets over half on the gauge, On a trip out to Ouray last summer I noticed the temp went up to where yours is as we were heading out of Denver on I 70 and it never came back down the whole time we were out there, Seems like a elevation thin air type thing.

 

Mine is an 08 so it may be different but
Mine never gets that hot I'm at 4400ft above sea level I often wheel in Moab where the elevation is about the same but it's all day idling in four low in temps around 100 even with my a.c. On and idling in traffic it didn't get that hot something isn't right I would flush my radiator both inside and out and refill with the recommended antifreeze remember to spray the water from the inside of the hood out until everything runs clear it could also be the fan if it's not engaging or if it's not spinning fast enough

 

Check for mud in the fins. You should remove the radiator to look at the fins on the A/C condenser and the radiator.
Flushing from the grill and the engine bay won't get the mud out of the fins between the condenser and radiator.

 

I am in Houston. Temperature and humidity is most days in the 90's. Even close to 100 degrees in traffic, my 2011 JKU does not go above the middle, with or without the AC on.
I also have a Aeroforce gauge and I check the temp accurately. Middle of the gauge is around 190 to 210. Where your gauge is must be close to 240. I would definitely check it out. Could be a sticking thermostat.

Good luck.

 

I would check the thermostat as well as flush and clean the system. Do you or someone own an infrared thermometer somyouncan get an actual reading. I had a pickup that would read high but was actually normal operating temperature. Ended up changing the sensor which brought it in line with the thermometer.

 

Thanks guys!!! it does seam to run a little on the warm side. I'll take it back in and have them look at it again. I wanted to be sure that no one was experiencing this temp regularly. I'm still a little paranoid having done a short block rings and an O2 sensor on my last vehicle 2013 that got traded in for being a PITA. I have it scheduled to go back in under warranty so I'll let them look at it. I don't want to remove the radiator here (apartment complex with no access to a gentile hose and not allowed to work on it in the parking lot)

 

Also it could be a bubble in your radiator. You mentioned you have a new radiator, so burping the coolant system could fix things.

Sent from my iPhone using JK-Forum

 

I may try that, just the cap was replaced the first time and it noticeably helped.

 

does the engne fan run?
-Christopher