I have a 07 wrangler sahara 4 door unlimited with some overheating issues. 130,000 miles on vehicle about 1,000 miles on new stock engine. The overheating started with the original engine and is still going one. I live in Colorado and it typically sets of the alarm when pulling my pop up trailer over passes. I have not let it boil over! It will get to about 3/4 on the gauge when just driving over some of the longer passes without a trailer. This started about two years ago about the time I got a power steering cooler installed infront of half of the radiator. I asked the installer and PSC (Power steering Cooler supplier) and they both said this cooler should not have effected the raditor and cooling. I have replaced the sensor, flushed the radiator with additives. The fan does run as needed. Any ideas?

 

Damage to the radiator or stuck thermostat would be a good place to start.

 

Since the problem started with the old engine, and this is a new engine which should have a new water pump and themostat, it's probably not either of those. Also assuming the outside of the radiator and the fins are clean, not clogged up with mud.

Troubleshooting order I'd use in this case...

The fan has two speeds, Hi speed draws ~25 amps and Lo speed ~14 amps. Lo speed kick's in at ~215F or when the A/C is running, not sure exactly when Hi turns on. If fan Hi wasn't working, that could be the problem. Some scan tools/programmers can test the fan HI, the dealer's tool definitely can. The radiator can be blocked with cardboard at idle, Lo fan should happen at ~215F and Hi fan at some greater temperature. A scanner or something similar would be better than just looking at the dash temp gauge, but as long as the Hi fan speed kicks on before over-heating the test would be successful.

The PS cooler might be the problem, maybe try putting it back to stock. Why did you add a PS cooler?

The radiator might have some plugging or scaling and the heat transfer ability has deteriorated, and replacement may be the only cure.

 

The add on cooler probably sits in front of the radiator and may be limiting air flow through the radiator. Can you post a couple of pics of how it is installed? Also, are you sure the fan is working?

 

I had a problem like this too. Mine eventually turned out to be the hose going from the radiator to the bottle. It would allow my water to go to the bottle but when everything started to cool off and produce a vacuum it would close the hose instead of sucking water back into the radiator. So I always had low water.

 

The cooler is in front of the radiator. I can hear the fan running. Not sure it is running at the two speeds. I did get a new tstat with the new engine. The cooler came with the PSC power sterring assist system which was installed with a new steering box to get rid of my death wobble. Which is did. I asked PSC about the cooler and they strongly recommened keeping the cooler in place. I could probably figure out how to by pass the cooler and take it out.

 

I still believe checking the Hi fan speed would be the first check, then maybe replace the radiator since PSC is so strong with their opinion of it being necessary and not causing a problem.

In any case, that PS cooler is going to cause a reduction in radiator heat removal, it's just a question of how much.

 

Yes, if the fan is not spinning up correctly get that taken care of and the problem should go away. If the fan is working correctly, though, look at possibly moving the steering cooler into the engine compartment and adding a fan to draw air through it (possibly with a shroud). You might look for somewhere you can draw cooler air through it in there.

 

steering cooler shouldn't cause a problem, I have a trans cooler mounted in similar place and no issues. is that pic recent?
I'd check for mud between the coolers and for mud between the radiator and fan
x2 on testing for fan high speed

 

Our Jeep struggles over Floyd Hill and near Georgetown when hauling our little utility trailer. I have to go slow and keep the a/c low. We have a supercharger in ours and while that helps with power overall, it doesn't seem to help on the big hills with the trailer. We are about to buy a bigger trailer so if you find a good solution, please share! I don't want to be one of those people pulled over on I-70 with an overheated engine.