First please forgive me if my terminology is wrong. But here's the short recap on the issue(s). Last week I was hauling mulch a few times back to my house form the landscape store. Jeep was running great. I turned on the A/C
during one of the trips, and a short time later the dash light came on and I saw I was overheating (almost pegged out). I switched the heat on and continued home. Temp went down drastically. On another later trip I tried the a/c again to see if it was just a fluke. Same result. Overheated. Got home and the coolant in the overflow reservoir was bubbling. Very hot.

If I read and understood some posts on here in my quick search... When the a/c is on the electric fan on the drivers side should turn on. Or if the a/c is off that fan should turn on if it reaches a certain temp? (is all that correct)
Fast forward to today, first time I had a chance to look at it again. Popped the hood, assuming above is correct, and turned on the jeep. Turned on the a/c and low and behold the drivers side fan (what I think is the electric /e-fan) came on immediately. WOOHOO I thought my previous troubles were a fluke.
NOPE. A few minutes down the road, and she overheats again. I park, pop the hood, and the drivers side fan (e fan??) is no longer running. I go home, turn the jeep off, pop the hood, turn the jeep on again, and then try the a/c. No luck on the the drivers side fan coming on.

I let it sit for a few hours. I try again. Pop hood. Turn on jeep. Turn on A/C. and the fan immediately turns on . I notice the fan may seem a little slow, possibly a little wobbling (not erratic). I watch it for a few minutes and I notice the fan slow down a bit, then goes slightly faster. But ultimately a few minutes later the fan turns off entirely. Thats where I left it, and began my search on the forum, but yet to see anything on this particular issue.

My jeep is a 1998. 4.0 4x4 Classic (I noticed years matter how the cooling system works)

So the overall question is what's yawls thoughts / opinions?

side questions- is that correct - that if the a/c is on the drivers side fan should be on as well , is that the "electric fan" (so I can be sure my terminology is correct)
All the posts I've read are simply about the fan(s) not working period ... or not shutting off when the jeep is off.
This situations seems different in that it starts off working (possibly slow though), and then turns off.
Also. when the a/c is on its blowing cold and I do hear the clutch engaging intermittently, and the fan on the passenger side is spinning. (if any of that helps)

Thanks as always for the the future / potential help and comments.

 

Yes, when the A/C is on the e-fan (driver's side) should turn on. I've noticed this generally means "when the compressor kicks on", not necessarily the whole time the A/C is on (at least on my 95).

I think the bigger issue is how you're getting so freakin' hot with the A/C running. I know the A/C systems are a little different between the 96 and prior and 97+ XJ's, but the general principles are the same. I get no discernible jump in temp from running the A/C vs. not, so why are you? I mean, the difference between running the A/C the not running is what - a little extra strain on the belt from the a/c clutch and the refrigerant cycling through the condenser and bringing some heat.... so why a jump from regular temps to overheating... it can't be the dinky e-fan running at 50%-ish...
In other words, I think the e-fan kicking on or not is a bit of a red herring - you should look at what would cause drastic heat increases from the A/C system being in operation. Is the compressor over-tight, causing a major load on the engine, is the refrigerant restricted in the condenser so the heat is not dissipating? Is the "normal" temp actually normal?
I mean, my first thought would be incorrect gauge reading, but you're seeing the coolant boiling over, so that's indicative of the actual temp being in line with the gauge.

Maybe someone with more A/C expertise can jump in and provide more knowledge.

 

@PatHenry thanks for the reply. That was another curiosity... “is there more too this than just the e-fan”. Especially, like you said with the big jump when the a/c is on... but truth be told I haven’t the slightest idea.

maybe overcharged? Undercharged? Other a/c related issues other than just the e-fan.

although a simple e fan replacement would be great haha. But I’d love to hear other thoughts before I simply start replacing parts.

 

Had all of about 2 seconds to look at it today.

started the Jeep. Saw e fan run. Then it stopped. I tapped the blade and it started slowly spinning again.

figured that alone was enough to show the fans bad... so ordered a new one.

Again, would be great if that’s the only issue

 

Good call, I think.


Yeah, that's always the bugger. One thing at a time. Get the new fan in there and see where you are, then go from there.

 

Finally got around to replacing the e-fan tonight after work, in the rain. Got the new one installed and the fan seemed to run MUCH better than my old one.
I let it idle with A/C on full blast for about 10 mins.
Drove it for about 30 minutes.(a/c on high)
Once back home I let it idle again for about 10 mins. (a/c on high)

I'm not ready to 100 percent that my issue is solved, and that's only because the temperature outside was in the low 50's, compared to 80's when I was having the issue.
I am pretty hopeful however since I let it run for a good bit, and she never even touched 210. I drove around for those 30 mins freezing my tail off, as I blasted the A/C, and the outside temp being 50's (also being soaked from the rain).
When I had the issue(s) the temp would peg out in short time after turning on the a/c. So again, pretty hopeful!

 

You're probably good. Without AC the clutch fan can mostly keep up with cooling duties but when that AC comes on it adds quite a bit of load and without the EFAN can't keep up.

 

Well, all seems well. I’ve driven it all weekend, in much warmer temps with a/c going, and she did just fine.
Today I even drove it two hours away to do some scouting for future camp sights, and trail riding a bit, then back home another two hours. Zero issue.
thanks everyone who commented.

*** to those who my stumble across this thread in the future when doing *keyword searches* for “only overheating with a/c running”
.....check your e-fan (for ‘98 models at least).
At only $40-50, and all of about 5 minutes of labor, my issue was solved.

thanks again to those who commented above

 

Keep in mind e-fan operation on 00+ models is different than older models. On older models the fan cycled with the A/C compressor as well as based on coolant temperature. On later models (00-01) the computer only turned on the fan based on coolant temperature regardless of AC operation.