jk4thedirt

Hello All,

I have a 2007 JKU X 4" lift, 37's and 5.13 gears, Auto.. I just recently upgraded the tires and gears. During the process saw that my water pump was leaking from the gasket. I changed the water pump and put in the HOAT coolant. Since then, my JKU temp gauge shows that it is overheating up long grades or on the fwy at 70+. I have read on here that a tranny cooler is a must With the bigger tires, which I will do this week. Would that also make the motor/radiator overheat as well?

Thanks for the help.

Noxian

Did you make sure to purge any air from the system when you replaced the coolant?

ronjenx

You may not have enough coolant in the radiator. When it cools down, remove the radiator cap and see if the coolant is up to the top.
If that's OK, you may have air in the system.
Do you have anything in front of the grill? (lights, winch, etc.?)
Is your front air dam in place? If not, you may have air getting up into the engine bay, which would diminish the air flow through the radiator at highway speed.
Is there any chance you have mud in the radiator fins?
Is the electric fan coming on when the engine gets hot?

Get an infra red temp gun, and point it at the base of the thermostat housing when the gauge says it's overheating. See if the engine is actually overheated. It would show temps above 220°F.

These are just a few things to look at.

TheTerminator

X2.

Air pockets in the system.

jk4thedirt

Thanks for the replies.

I did let it run for a while with the cap off and the heater running. It did give a lot of big burps and had to add in more coolant. It took a very long time for the thermostat to open. The fan seems to run all the time. More so lately, it's been 95+ here this past week.

It has never seen the mud.

I do have a winch and lights in the front. And no air dam. It would fit with the new body armor bumper. I will try to get it to fit again tonight.

jk4thedirt

It also seems to lug along. It doesn't have very much in the skinny pedal. We do have to give it a lot of pedal to go up any decent size hill. Do you think it could use bigger gears? Maybe 5.38's?

69mach1

I have the same combo 5:13, 37's, Auto, and the hills are still not a nice place to be My wife has to remind me the power is just fine once we get off road (4lo) 5:38's would be better on hills but I didn't want to put in something I knew I would break So I deal the best I can with low power & poor MPG up the hills... till I can score a nice 5.7 Hemi

I'm in Socal so hills are every way I need to go

jk4thedirt

I'm in the same boat as you. We have 2 ways home and they are both long up hill grades. It's ok driving around the city street in Riverside, but don't think you can pass anybody on the fwy or come home without going up a hill. I wish I could add a ripp or Hemi. I have too many other projects I'm working on.

Thanks for the input.

TheTerminator

Down shift to get more power out of the engine. Turn off over drive if you're at highway speeds. Shift to 2nd if you're in town.

jk4thedirt

Thanks Terminator. I will try this.