I've had the jeep almost 2 years. Its a 96 XJ 4.0. I love this jeep.
After learning so much here I finally made it to the junkyard (there aren't many here in South Florida) to see what I could find. My XJ came from a yard north of here and had been saved by a guy working there. It was covered in grease inside and out but so am I ,I bought it from him.
Its run fine for me all along and I love the inline 6.
Well, the efan exploded driving home last week, brittle and old, it disintegrated. I went looking for one and didn't find so I put an aftermarket comparable to it in. While at the salvage yard I spotted the coveted instrument panel that would allow me to do the "gauge swap" I read about on here. I've always had the idiot lights and since I tow a boat some I've always hated the idea of the overheat light coming on without warning even though its never done that even after the efan broke. I did the swap.
New fan works just as its supposed to maybe. It comes on when I turn the AC on.
The new gauges look great and all function. I had to hunt for the right temp sender for the temp gauge. (Big long hot story there). When I found the right sender, put it in, cranked her up, I watched as the temp climbed past 210 almost reaching the red area but it didn't. Turned on the heat, came down a little. Drove around the block, came down a little. Turned on the AC, it stayed high but got no higher and the efan came on.
All this was yesterday and today and I haven't really taken it for a drive around town which would involve alot of stop and go. Its close to 90 degrees here and I'm in full sun.
I know:
The guy I bought it from had put a radiator in so there was probably a problem at one time.
Its not a new radiator.
I've never seen the overflow bottle high. Doesn't mean it hasn't but I think I would've noticed since I'm obsessed with overheating fears.
The top on that bottle is loose but its not a sealed system anyway right?
Its got coolant (not sure how much though but looks very green)
It has the tow package with transmission cooler.
Its never failed me and it gets really hot here in Summer.
No leaks and hose doesn't collapse.
The red warning light had never come on.
I was freaked watching the temp climb so high.
I don't have a heat infrared gun (I'm poor and outta work)
I want to keep this jeep forever (gonna just paint it myself with a sprayer)
Thanks for hearing me out here. Ideas where to begin? I've read so many overheat issues and never knew I was overheating.
Could it be?
Efan -it kicks on with the AC but shouldn't it run as the temp is climbing?
Thermostat?
Radiator flush?
Bad sender choice even though its new?
Calibrated gauge for another year? It fits perfect though.
Should I run it and see if water overflow fills up to hot line?
The other temp sensor that kicks on the fan comes on at what temp?
Any other ideas are appreciated and where to begin.
Thanks again a million times for reading this. I've read and read and learned so much here.

 

1st thing i would check is the mechanical fan. It should spin relatively easy when cold and once its heated up it should spin much harder. (spin it by hand with engine off)

and yes the efan should kick on when it gets over 215 or so. Mine never did tho

 

search clutch fan might be yous is bad

 

thanks, the clutch fan seems ok. Stops quick when hot and spins freely cold but I read where these wear out and seemed fine. Cheap enough to try I guess but hate throwing parts. Said that even though I just ran out and bought a new coolant temp sensor since that efan doesn't come on at 190 - 195. The part was wrong of course and doesn't fit the plug going to it. I think I want to try that if I find the right part. Would a new clutch for the mechanical improve things if mine is just on its way out? That is, if they give me the right part. Its frustrating cause customer service is so bad at my parts stores. I do have a Bennett nearby but no NAPA. Its Autozone or Advanceauto. At least Bennetts will look at ya when you're talking to them.

 

if fan tested good dont buy another

 

Ya know, I went out to check that clutch and turned the fan and its still not spinnin freely. The engine is a little warm, got the hood up but the sun just went down so I'll check it in the am. Should spin easy when cold right? Reading some more, it says the light should come on when I turn the ignition, then go off. I've never seen the light ever. See the other lights and checked the bulbs when I did the swap but don't know if I should be seeing that warning light to tell me the bulb is good. Anybody know about that? Man, the 96 was the most numerous built but I'm seeing so many conflicting parts and setups.
Thanks for your input. Will check in tomorrow after the fan clutch test when cold.

 

you stated you have a gauge you will only have one or the other your old cluster had the light new has gauge

 

it could possibly be the wrong sender for the gauge's. if you still have your old ones, you can always try installing the old parts and see what happens. assuming you didnt have to hack anything apart haha. when i swapped my cluster, i didnt even need a new sender because it was a similar year, but i havent had any major problems with it since i put it in.

 

I did try the old sender since I had trouble finding a new one. Even bought a new sender that was the same as the old one by mistake. Both senders, the needle just sat there on O. I finally got the correct sender for the gauge and thats when I saw how hot it was runnin'.
Checked that fan clutch this am. The cold fan spins about the same as when it was hot. It'll turn but not spin a complete revolution.
I've seen conflicting info on that. Some say it should spin freely cold but less than 5 revolutions. No way will the fan spin a complete revolution cold or hot. It seems the same each way, hot and cold. Gonna search on that but wondering about my T-stat. Like mentioned earlier, I thought the efan should come on as the temp is rising but it's not. That sensor sits in the housing before the t-stat. So if the T-stat is late opening up or hardly opening at all maybe its not sensing the hot coolant thats in the engine?
Think this all is related. I do remember the last time I knew that fan was on was early in the morning on my way to school. I could hear it. Pulled over and checked it to find it rubbing on the pulley of the power steering pump. It was early and a cool morning but I figured it must be coming on to help the engine warm up to operating temp. Now I'm watching it and it comes on only when I turn on the AC.
Thermostat? Clutch fan? Bad sensor? What ya think?

 

When I had a heating problem on my '91, I checked things in this order:

1) Thermostat (195* here in VA, maybe 180* in hotter areas)

2) Hoses

3) Sensor and sender

4) Mech and elec fans

5) Water pump (check for coolant from the weephole or any noises signaling failure)

6) Clogged radiator (plus if you live in a hot area, the stock 1 row might not perform the best; I recommend radiatorbarn.com with any rad needs)

 

I just went out and started it up since its been sitting all night and cold. Kept my hand on that radiator hose all the time and ran to watch the gauge ( back and forth). That coolant started flowing right on time til I couldn't squeeze the hose and it got hot. Good flow.
What else I noticed:
The temp climbed fast AND the efan never came on. Then I also see a little drop of coolant coming from the radiator cap. A continuous drip. I've had it on and off plenty in the last couple of days so not sure if its done that all along.
New cap for sure since I've never seen that overflow coolant bottle fill up. I blew through the hose to it and there was a little resistance before it opened up so it may have been clogged.
Off to the parts store. Will get that cap plus the correct efan sender. I think I should replace the clutch ( its said its a regular maintenance thing every 4-5 years and it looks original.

 

anybody know at what temp that efan should kick in? I've read 195 and 219???
I've now changed:
electric fan (works when AC is on)
radiator cap
Both senders, although I've got a 96, the only coolant temp sender that fit is a "97.
relay, also a '97
doing a flush right now and changing the thermostat. Saw a tiny leak and discovered no gasket where the thermostat housing fits so got that and new 195 thermostat.
Gonna give it new coolant too.
The old t-stat did have some black gunk on it although the coolant looked great? It may have been the silicone gasket material they used to hold it on. Can't wait to see what comes out with the flush.
I know I'm log winded but want to explain all I've done so far.

 

FSM says 218F.

 

thank you for everyone's help. It seems to be running ok now but I've change out everything but the fan clutch. Hoses too. That lower hose didn't have a spring but it was soft and when I took it off it had 1 real weak spot. The parts guy at Bennett said no springs except from original.
Thing is, I drove in stopand go all day yesterday. It did fine. Right in the middle except at idle when stopped at redlight. It would creep slowly up. Turned on the AC and it went back to middle.
I noticed the parts all said with or w/o AC so I think they designed the thing to either have the ac or heater on. No fresh air.
I don't think my efan kicks on unless I have ac or defroster on. So when it creeped up, I turned the defroster on but with cold temp and it returned to normal temp.
Driving a distance on interstate today so that will be the final test. If ya don't hear from me thanks alot. I never would've checked the hoses and that lower hose was shot.

 

all the way to Miami and came back A1A along the beach. Its a hot day with lots of stop and go. Ran the AC the whole time and the needle stayed right around 210 give or take. The take-away from all this is that I'm extremely glad I did the swap to gauges. That part was easy and helped me prevent an upcoming catastrophe I reckon.