I know you just replace the stat in Oct. but sometimes they go bad.

My temps suddenly shot up last week, I replace the 2 year old stat and she immediately ran cooler.

Cheap and easy fix.

 

I installed a Oriealys 195 one. Same one that's been in my dads LJ for years, he's never had a problem.

I can tell you I've never felt that much heat off my engine bay before, possibly a mental thing but it felt super hot. If it gets hot again I'll verify the temp.

The clutch did seem bad, I could spin the fan easily with the bay super hot, like it wasn't fully engaging. So, who knows maybe I fixed it, it looked old too. Never been replaced in 18 years/ 211k miles doesn't bode well.

Thanks for all the help guys, I can understand electronics and mechanics, but the cooling system is just harder for me to wrap my head around.

I texted the PO, (I know weird but I never deleted our initial conversations about buying it). He said new water pump, radiator and thermostat(which I already replaced) were installed before I bought it.
Coolant was also flushed.

 

I noticed my fan clutch went bad when the efan came on for what I thought was no reason. it spun easily with the engine hot, as well. hope you got it figured out.

 

I live just outside of Denver and the steep hills around here (Lodo to Highlands, for example) takes a toll on the auto transmission temps. One thing I would highly recommend is a secondary transmission cooler. The stock setup routes the transmission fluid to the side tanks of the radiator, so if you're getting either one hot it'll help the other get up there too. An IR gauge will help you pinpoint it but if you're in stop-and-go traffic or your transmission is shifting a lot without torque converter engagement you could get that fluid 260°F+.

What does your AW4 fluid look like?

 

XJ's run hot as HELL in my experience. No thermal insulation really hurts things as well (heat in the cabin)

I have to drive from DTC to Westminster at 3:00 today, air temps are supposed to be ~92*F plus intense sun, plus gridlocked traffic. No AC in my rig means I am going to probably suffer heat stroke by the time I reach the I25/US36 interchange, total drive time is probably going to be 1.5 hours up there.
I'll let you know how it does! IMO - you are either running into an airflow (fan) issue, or a coolant flow issue if your rig is running that hot.

My XJ still never exceeds 210, even when I am stuck in traffic. Manual trans probably helps, not running the AC definately helps. My E-fan is broken and doesn't kick on either, but my fan clutch is ~1 year old and starts screaming when the clutch engages. Holding the RPM's at 1500 really dumps the heat out as well. Even still, mine barely exceeds 210 unless I am at a complete standstill and let it just sit at idle.

EDIT:
On the top of my to-do list is to get a new e-fan and to wire up a manual control switch. Is your e-fan kicking on when it gets past 210*F?
A standalone transmission cooler is highly recommended - separate the engine cooling system from the trans cooling system. Personally, I would mount the cooler in front of the XJ mechanical fan. More consistant cooling and when the E-Fan kicks on the coolant is already pretty hot and I would hesitate to block the auxilary fan any moer than the AC Condenser and radiator do.

Flexalite and B&M both make great coolers, and $50 is pretty cheap for such an important mod;
https://www.summitracing.com/parts/f...FZaEaQodK0oJ3A

 

E fan works as it should. Tranny fluid is a darkish red. I've been thinking about a tranny cooler, however a lot of this hotness is when it's in Park. With the new clutch temps stay at 221 or below now. Keep in mind there is no shroud at the moment.

 

A shroud will help immensely. If you are already running that cool you are probably in good shape. Still a good idea to do a beefy trans cooler though, help prolong the life of it significantly.

I am going to make a thread about thermal insulation after I lay down some FrostKing duct insulation on the floors and trans tunnel. My cabin is a solid 30-40*F warmer than it is outside. Freaking sauna right now

Luckily it is cloudy and wasn't that hot of a ride up. XJ stayed super cool though, never broke 210*F

 

That clutch. Above 2200 rpm it sounds like I have a Jet engine under the hood if you're not moving and revving it. Lol.
But temps were significantly lower today, however it didn't get quite as hot today.
So maybe it's fixed, maybe it isn't. It supposed to be a scorcher tomorrow so I'll find out then.
Thanks for all y'alls help.

 

So today with the AC on it maxed out at 231 with the AC on. Without the AC on it stayed at about 220.
My compressor is a little noisy like it's going out, is it possible it's putting more drag than usual on it and that's why it's getting hot.
Revving the engine, the temp fluctuated between 215-220.
I fixed the fan, water pump or thermostat next?

 

hmm. I am not sure about that. I had you in mind while I was sitting at a train crossing today. it was 92*. I stopped almost immediately after a 50 mile drive at 70+ mph. the ac had been on full blast for almost an hour. I sat 13 minutes and the temp needle didn't fully hit the 210 mark. I doubt the thermostat is the issue and if you've already addressed it I would look elsewhere.

 

I'd be uncomfortable with that temperature. I'm sorry if I missed it, but did you actually see the efan kick on at all? I know for my 2000 it's supposed to kick on at about 218, I got to 215 and was worried it didn't work thinking it should kick on at 210. For 99 and older, I think it should come on sooner. Check connections, fuse, relay. Hook up a modis and see if you can manually run it, it'll tell you if it's working or not atleast. It was 100 here today and with ac blasting I didn't go above 215. The last place but a possibility that I would look at too if fan works but somehow isn't turning on is the ecm failing to send a signal. Good luck

 

E fan most definitely comes on, I can hear it and when it kicks in the power drain is obvious. I climbed a mountain tonight and it never got over 220, with the AC off.

 

All kinds of Denver happening in here. I need to replace my clutch this year, its the only piece I never did.

 

Did u put a shroud on?

 

No I have not, haven't had a chance to get on from the yard, although I broke my original trying to get it over the new clutch, I'm gonna need to be creative on how I get the new one on. Lol.

This Jeep never fails to annoy me, last night my rear O2 sensor wiring fell into the rear driveshaft, so now I need a new sensor and need to do some soldering.

Sorta unrelated to the thread topic, but the wiring tore the boot over the slip yoke, it that important?