Josh Edstedt

Alright, so I’ve got a 2013. Been having overheating issues for a bit now. Anytime I get around 3k or higher rpms, my Jeep starts to get hot. It’s never gotten to the red but only to 3/4 marker hot. But as soon as I’m back down to under 2k it cools of pretty quickly. Been doing that for awhile now. The serpentine belt shredded a couple weekends ago because the water pump seized up. Replaced water pump, couple idler pulleys, and the belt tensioner. Refilled with OAT coolant. Still didn’t fix the issue. I ran the Jeep with the rad cap off yesterday and after it reached temp, it starting boiling and seeing out of the rad cap opening. Which led me to believe that the thermostat wasn’t opening. So today I replaced that, did a full flush of the radiator and even cleaned the radiator fins. Still wanting to get hot at this point. I also did a combustion leak test on it and nothing. God help me if it’s the head gaskets. So my next solution is I’m going to buy a new radiator. I haven’t seen any leaks and I’m never low on coolant. Anybody have any ideas as to what this could be?

-new water pump
- new thermostat
- complete rad flush
-combustion leak test done(negative)

Rednroll

Is the fan coming on and at what temp if it is?

Maloy1237

Sounds like what salt water boats have. Your passages in the engine might be clogged. When you flushed your radiator, did you have any gunk? Try to add some radiator flush cleaner and flush it again to see if that will work.
At low rpms, your cooling passages are fine, but when you increase RPM, if they are clogged, water will not pass...

When you did compression check, did all your pistons matched?

HostileJK

If the fan is coming on I would try and burp the system as it may have air stuck in the system, jack up the front end and squeeze and release the upper rad hose until it coughs up the air.

AZJKU2017

I just repaired a jeep with this exact issue, customer replaced pump, tstat, radiator, and fan due to overheating after 20 minutes of driving or freeway speeds, this thing would almost redline on temp gauge. Block test showed nothing and it wouldnt run that hot at idle, i ended up tearing it down, removed heads and checked for warping, and yeah they were warped about .006 -008, they say nothing more then .002. Installed new heads and gaskets and it stopped overheating. Depending on mileage i would just replace engine with a rebuilt if it was mine, or hemi swap it...

LC Boyer

I painted the radiator on an old CJ-5 once, many years ago. It started to get hot, I replaced radiator, fixed it

nighowl2000

Just re-did my cooling system last month on my 2014 jku @ 94 000km.

parts i used:

waterpump:
https://www.rockauto.com/en/moreinfo...=1089&jsn=1089

thermostat:
https://www.amazon.com/Dorman-902-85...ype=automotive

Belt:
https://www.rockauto.com/en/moreinfo...00356&jsn=1103

antifreeze:
OEM Orange II - The Easy Match Antifreeze / Coolant for Your Vehicle

================================================== =======

Flushed out the old purple MOPAR OAT fluid with distilled water over three days then replaced coolent system. Also sprayed out back side of rad (where the fan faces) and removed plastic top rad cover and rear hood seal as well as engine cover.

I was getting spikes of 230F in stop and go traffic as well as heat soak after 30+ min of driving. Now runs between 206-215F.

Also run A/C system if really hot outside

Sunnysideup

A radiator cap that is not working right can cause an overheat issue like this too!

LC Boyer

Have you found out what the problem is?

Law4110

My 2013 started overheating, it was low of coolant. The Jeep dealer serviced it, burped it and got it back. It started again, so the water pump was replaced, next the thermostat, thermostat housing, radiator cap, radiator, heater core, left head and gasket was replaced, the temp gauge does fine idling but drive it 10 minutes and the gauge goes to red and the light comes on. The heater doesnt blow hot anymore, I shot it with a temp gun on all cooling components and the highest temp I get is 195°. I was going to replace the engine coolant sensor next, I don't know what else to do,any suggestions?