XJs with factory tow packages came with "heavy duty" radiators. These were 2 core (I believe) so they would be thicker. Standard duty is one core. There are aftermarkets ones with 3 cores available.

You can look up in the FSM to get the resistance values for the sensor as a function of temp. As suggested, verify temps with an IR thermometer at the tstat outlet. The sensor sends it's output to the PCM that then adjust engine parameters to suit and the signal to the temp gauge.

 

So which T-Stat temp is best for our XJs? The factory recommended 195 F or the alternate 180 F ? Pros and Cons to each?

 

The question is not whats best?....it's what's best for your jeep. In the summer with a 2000/2001 that has no aux fan until 220+, if i run the ac in traffic with a 195, I will overheat. A 180 I can run intermittent ac. In winter 180 is not enough heat. And with a 195 keeps me around 200 to 210. 210-215 is great for emissions thus a195 stock...how many jeeps overheat on this forum. I can run a 195 all winter and not have any issues but you probably cant say that where you are in july. Are you doing the work yourself or paying a shop to do it? What did you run before it started showing cold? Whats in there now? Have you verified your sender accuracy?The political answer is engineers designed it for stock parts...but we learn pretty quickly that was 30 years ago and mostly impractical..thus your desert rated radiator. Choose 1 and replace or modify if it does not work as you expect or want

 

Good points there bluejeep2001...
I know when I did mine a few years back that I went with the 195 with a jiggle hole at 12 noon for escaping air in the system.
I'll have to pick up an inexpensive temp gun to see what temp it really has at the block, that would be a lot cheaper that getting in the dog-house by my wife for boiling a jeep part in one of the good pots. lol
And will pick up both temp T-Stats, those are pretty cheap for decent ones.

 

Get a couple of extra gaskets too

 

Just tell her you're getting into sous vide.

 

Well.... she IS going to be out of town for a few days.... what she doesn't know... won't hurt me

 

This is where it has been sitting or a little closer to the lower mark below the needle when the engine should definitely be at full operating temp.
This is with a 195 F T-stat. Which is out of the norm for my XJ. It generally was running with the needle just below the 210 mark on the gauge.

For those running a 195 F... where does yours sit at full op temp?

 

These are with my robert shaw 195 ..after a 30 min highway cruise into work at around 30 deg..Remember with late model single source instrumentation there is no available backup comparison. No matter what the actual coolant temp, the gauge and scan tool will read exactly what the sender puts out no matter that its accurate or not. You will never know without additional external testing.

 

should have been with the above post

 

I had a coolant temp sensor start to act up a few years ago. It would suddenly read low for reasons that didn't make sense. I replaced it, and it's acted normally ever since.

 

I had a sneaking suspicion of that... so may end up ordering a new one.

 

I was able to obtain a decent temp gauge... the block read from 185-205sh depending on where I pointed it. Obviously the exhaust side is a little higher around 215 (which I would think is to be expected)
when I pointed it right at the T-stat housing it consistently read about 185 degrees F. Same for when I pointed it right at the water pump.
So maybe the gauge is reading correctly... but what would cause this change? If it's reading accurately?

 

Dead on the last hash-mark before 210 is 180 to 185. If all your temp guns reading are 185 and up then your sender must be off. The only real test is to remove and drop in a pot of boiling water with some wires connected to the terminals and read the resistance. I don't have the resistance chart for 212 deg...but im sure someone will post. Ballpark 650 to 725. You might as well do the thermostat since you will have the water level lowered. Question is how hot do you want to run, or will you run with a 195 tstat in texas summer. If you can keep 210 or below in summer with ac in traffic...then go 195. If not go 180. Verify sender with the boiling water and a meter or your just guessing and then choose . I hate to sound gruff but its been a month and you haven't changed a 20 dollar thermostat or truly verified your actual sender calibration..both could be done in an hour

 

to answer your question blue..... the XJ doesn't get driven that much anymore so as busy as my schedule is, changing that out isn't priority 1.
Just wanted to be in the right direction for when I do have time.