Over-heating issues

[Zstairlessone]

Just a thought, but at 5500 RPM the 3.6 is making about 25% more torque and power than the 3.8. Making more power creates more heat (which needs to be rejected) and if the cooling system was never upgraded when they put the new engines in, well that may be the issue.

Like I said, just a thought.

 

[Parker "P.T." JK]

I'm looking at the Stant 160 degree thermostat. Do I need the gasket as well? It's on amazon. I'm also looking at the Mishimoto Tranny Cooler and Silicone Hoses

 

[steve_r2]

240 isn't bad but it also isn't good. 260 cracks heads and blocks. Like I said a 160 thermostat will help it keep cool because by the time it hits 195 it is just to far to cool back down quickly when it hits 160 it will open the thermostat and help keep the flow going instead of you coolant making a lot of stop and go flows it will make longer flows to get all the cool coolant out of the radiator and flow in the hot coolant out of the block

Which 160 manufacturer would you recommend ? With where I live and run engine/cooling is one of the major concerns I have and hopefully doing this will help.

 

[billybob990]

Well you will have to give me some time here. I'm going to have to do a little research to find them for a 3.8 and 3.6 because my catalog doesn't have then in it

 

[Dagub]

Well I finally found a useful discussion of this problem. Maybe I can add something. I spent a week driving around the Colorado Rockies with a small trailer this summer, and experimented a bit. The Pentastar has more horsepower *and* more torque. If you want to scream up the pass at 60-65 mph, 5000 rpm, the motor will do it, but the temp gauge will visibly climb too. If you keep it out of passing gear, around 3000-3500 rpm, the motor will lug you up just fine around 50-55 mph, and you can watch the temp gauge go right back down to the mid point.

Other notes:
The same thing happens without the trailer
Turn off the AC
Take the winch cover off (I have an 8274 which sits in front of the radiator)
I have never had the temp go up on the trail
I will be looking for aux fans; warped aluminum heads are a terrible thing

 

[Marauder]

Mine does it too when I climb a steep grade and the rpms are high. The guage visibly climbs. I took the winch cover off and will see if it helps.

 

[LiveOn]

Now this thread hits the market!! My 2012 JKUR has been at the dealership for the past month and it has been a non-stop battle with the dealership due to the fact that they couldn't find anything wrong. I even did a ride along and showed them when a load was on the engine (hill climb or trailer pull) the engine would hit 3/4 temp every time.

So I called my buddy with S & L engines to figure out what they have heard. Found out the initial 2012 engine heads were miss machined and the heads do not pull the proper amount of coolant through the engine.

We got Chrysler on the phone and a case # was generated on the jeep!! We ended up replacing the left & right side heads and removed the timing cover to verify there was no flashing.

Now the engine is fixed and the jeep runs like a champ. I still am thinking about dropping a larger radiator in with dual fans just because I don't like a warm engine.

Hope you find a fix my friend!!