Temperature gauge

[8Mud]

I´ve seen different temp. stampings on the flange of various thermostats, most were 195, some said 193. I´d check the book, the OEM Chrysler seems to work best. But then again, I´ve checked thermostats, with an electronic thermometer, it´s often 195 plus or minus 7-8 degrees. I´ve rarley found one that opens at exactly (or plus or minus a degree or two) of advertised specs.

 

[tireroastin93XJ]

I´ve seen different temp. stampings on the flange of various thermostats, most were 195, some said 193. I´d check the book, the OEM Chrysler seems to work best. But then again, I´ve checked thermostats, with an electronic thermometer, it´s often 195 plus or minus 7-8 degrees. I´ve rarley found one that opens at exactly (or plus or minus a degree or two) of advertised specs.

I guess Monday I'll go to my Jeep dealer and get a thermostat, don't want to screw anything up. Then I'll start upgrading the cooling system. Why doesn't the aux fan switch kick in until the a/c is on? Shouldn't it start the aux fan regardless? Where is the aux fan switch located? Are there replacement ones that make it come on sooner? If not, guess I'm going to go to Auto Zone for their kit. Thanks for all the help! Sorry, I didn't mean to hijack the thread.
Mike

 

[Atl XJ]

I've done a little research on this and according to what I had come up with, the OEM 195 degree is the best to run for optimum efficiency out of your 4.0L. If your cooling system is operating efficently (which mine apparently isn't) the 195 degree thermostat is more than adequate too keep your 4.0 cool. They do run a little warmer than your average engine, but I'd be exstatic if mine would stay at or below 210 degrees.

 

[Atl XJ]

Why doesn't the aux fan switch kick in until the a/c is on? Shouldn't it start the aux fan regardless?

It should come on at 217 degrees regardless of if the ac is on or not---like Eagle stated previously.

 

[Atl XJ]

I just wanted to post an update here. It looks like the problem lied in my thermostat all along. It was only six months old, but I had some previous overheating problems and I guess the thermostat got damaged. It barely rises above 210 in traffic now (and only for a minute before it cools down to 200 or so) without the a/c on. With the a/c on it runs cooler. I also changed out the radiator cap with an oem model for good measure. I hope it still cools well when it gets hot outside. Thanks everyone for your help. arty:

The only thing I want to do now is rig up some sort of override switch for the electric fan so I can switch it on manually. :greensmok

 

[Eagle]

Is 195* the only thermostat you are supposed to run in it?
Mike

Yes