Great questions, Philippe. The e-fan definitely comes on with the AC but I'll have to check and be sure it's coming on at 220. The fan doesn't appear to be damaged, though I did discover a crack in the e-fan shroud that doesn't seem like it's affecting anything. The belt is tight - around 160 - I've got a tension gauge that I always use when retightening. Last night I even rechecked the belt routing to be sure it was correct since it's acting like the water pump is not working, but it's brand new and looks just like the other one. It's got the "R" stamped on it for reverse rotation. Which reminds me, I did see someone on here say to be sure NOT to have a reverse...?!? Finally the fan shroud is in place and nothing appears to be blocking the radiator. I will say the AC condenser looks bent inwards and is probably touching the radiator - any chance that would be causing issues? Hard to believe that could stop flow inside the radiator...

One more detail - this motor is out of a 97 even though it's a 95 XJ. Shouldn't change much but worth mentioning.

Thanks again for the help!

 

Bent condenser (even when touching) shouldn't be the issue. Flow should be good, indeed. Belt ok, so that isn't it either...
I honestly can't think of anything else and I don't know about the 'R' on your water pump.

I do still want to advice to make a small trip (even if it's just in the neighbourhood, but on a decent speed) to see what temperature you get.

 

Yes! Sorry, forgot to mention that - I've currently got the dash ripped apart doing some wiring, but in the next few days I'll get it back together enough at least to give it a short drive. Earlier in this saga I drove it several times and the temp always stayed in basically the same area. Hmmm.....I don't suppose the temp sensor could be bad?? Would be mildly hilarious if the motor/cooling system was actually doing exactly what it's supposed to this whole time and the sensor was bad...haha...I'll research that now, why not.

 

Update: got the Lisle funnel (again), finally figured out how to get it work on the XJ, and burped a BUNCH of air out of the system with the jeep parked on an uphill. A lot more than I thought would have still been in there. I don't know that the level in the funnel really got much lower; I did have to refill the reservoir some. Unfortunately, no change in the temps - still holding steady at 225.

I did get a replacement, NTK-brank coolant temp sensor on the off chance that I was getting a bad reading - again, no change. I put the dash back together just enough that I could drive it a bit and took a lap around the neighborhood - held steady at 225. I just don't have a clue what the issue could be.

I did notice when burping that the e-fan did NOT come on unless I was running the AC - I believe it's supposed to come on around 210 and stay on until it's at or below 210 - not happening here. It does come on immediately when I turn the AC on. I ran the AC during a good part of the test drive and the temp didn't come down much if any.

One thing to note is that my XJ is a 95 but the motor is out of a 97; I believe in the older XJs there were two temp sensors - the one in the thermostat housing and also one at the rear of the head cover. Interestingly, I've got both - sometime last year the temp gauge quit and I found I could pull the sensor at the rear of the head right out of the housing, so I replaced it and the gauge read correctly again. So, it appears I've got some kind of weird hybrid XJ now - but the temp was holding steady at 210 until recently, so something is amiss.

Fellas, I am FRESH out of ideas - I'd be grateful to hear yours! Especially about the e-fan not coming on with high temp - BUT, it does come on with the AC and didn't decrease the engine temp, so looks like even that is not my real issue...sigh...

 

Hmmm. I don't think you should have reverse flow, but someone check me on that.

 

^^^ this... always put your jeep or any vehicle with front mount radiator system on a slight hill with the radiator facing up the hill. That helps the trapped air bubbles make their way out of the system more easily.

 

Just out of curiosity here.... are you positive that the temp sensor is actually still good?

 

Rocketmouse, you hit the nail on the head!

This afternoon I drove it to O'Reillys where they had a laser temp gun - I wanted to know once and for all if it was running hot or if I had some sort of gauge issue.

WELL GUESS WHAT. It was probably a 10-minute drive with an outside temp of 80, and the gauge hit the "new normal" of 220-225ish about halfway through the drive. Once I got there, the thermostat housing was reading 170. It finally climbed up to 180 over the course of several minutes. I asked him to shoot the area near the temp sending unit, at the very back of the head, and it was 190. Ceramic-coated header was 250. He checked everything multiple times and it stayed consistent.

So - looks like this thing is NOT overheating after all. In fact, it appears to be running cool. First of all, I'm hugely relieved that it's not the head gasket - it's not a job I can't handle but after all I've been through on this issue I'm ready for it to be roadworthy again. Second, it sure looks like I've got a gauge/reading issue. I was suspicious when it would come up to that 220/225ish "new normal" fairly quickly, as an engine would normally climb to operating temp, but then stay there no matter what. I remember replacing that sending unit about a year ago since it was broken, but I don't remember what brand I used. I think back then I didn't yet know that NTK was the way to go and probably just got whatever O'Reillys had on the shelf. To be safe, I'm ordering an NTK and I picked up a new wiring harness for it at O'Reillys since they said that those tend to go out a lot. As a last resort I may have to clean the contacts on the actual gauge itself, but I'd like to avoid taking the instrument cluster out again if I can since I have unfond memories of the last experience.

So I'm NOT crazy - and looks like all the coolant system work has paid off. I will feel a LOT better when she's reading 210 or less all the time, however. Sure appreciate all the help - I'll report back!

 

Whoa! Wait as minute! I don't think that has been established yet!



Glad you got it sorted out!

 

UNFORTUNATELY I AM MOST LIKELY CRAZY

HOWEVER

I am considerably LESS crazy knowing that this thing is actually cooling like it should!! Nothing made sense - seemed she was operating just as she should and no obvious signs of head gasket failure. Well - another lesson learned Will report back with the results of this next batch of parts!

 

I miss the old days when you could buy a part and trust it. F China!

 

Isn't that the truth

 

Haha - I wrote it in all caps and it "fixed" it to that...let's all stop and thank the people who EXCLUSIVELY write in all caps for making that necessary

 

Hey all - I've been slow to respond because I'm not totally sure what to say. I replaced the old coolant temp sensor (the one in the back that feeds the gauge) with an NTK one, and though it was the same off-white plastic housing, it took a different size wrench, so that's pretty good evidence that it wasn't an NTK. Once I did that, I started it up and let it idle for a while and it sat with the needle just to the left of 210 - absolutely perfect!! It came up a little bit during a 10-minute drive, and got a bit over 210 when idling after driving. I figured this might be normal and to be expected and then didn't drive her for a week or so.

Today I drove her about 10 minutes, then idled for about 10 minutes, and it got up to maybe 230. Which I simply don't understand. As soon as I began driving again, it dropped right back down to around 210. Then I let it sit and idle again and it stayed at the same temp. So I have ABSOLUTELY no idea what's going on. Why would it get quite hot after driving once, but then not do it later??

I've replaced absolutely everything. But getting hot while idling does seem to point to the fan clutch...I've still got the ZJ fan clutch since it hasn't sold on FB marketplace yet, so maybe tomorrow I'll get it put back on and see if that makes a difference. I REALLY don't want to keep it on as it's just so loud and it does rob some power - but all I can think is maybe my new fan clutch isn't doing what it's supposed to be doing. Would there be another way to test this fan clutch to see if it's the problem?? It's the brand-new Napa 4.0 one.

Sure appreciate all the help, all - thought we were done but not yet apparently

 

Hey all - thought an update might help somebody else. It's certainly cooler now (highs in the 50s) but I've had no trouble with overheating. Seems to ride just a bit over that 210 line, but doesn't seem to be bothered - that might just be where this one sits. I'll see what happens next summer but for now I'm just going to drive it!