1990 XJ Overheating

[carpenle]

I took the Cherokee out Sat. to do the Moody Hill/Ballard Rd. run with the group. It was about 55 miles to the meeting spot, Jeep ran great on the Hwy and had no issues. Actually did really well on MPG at 21 MPG. This was my maiden voyage with the XJ. After we left the meeting place and got in the hills, the Temp started to increase. I let it cool down when we stopped to air down, but when going up to the trail head, it started to heat up again. I decided not to proceed and turned around. My question is, is it worth changing out to an open system? My pressure tank seems to hold pressure, but the Elec. fan (I found) is not switching on. I am going to replace the elec. fan/switch, remove the AC condenser (AC pump converted to air pump), and do a flush the system (possible thermostat). I am wondering if I should change it to an open system, since I am going to have it apart, or is it not worth the effort or money? I am hoping the elec. fan will cure the issue, but I am wondering if I have something else going on.

I know this group has a lot of XJ's :D, so looking for insite on how to cure the problem.

Thank you

[Java]

I don'thave an XJ but I do have a 4.0 and they're not known for overheating. I had an open system in my YJ 4.2 when I moved here from FL, works terrible in the winter, no advantage in the summer, IMO.

[Java]

***

[carpenle]

It is the 4.0 and never heats up in town. It was when I was pulling the hills that it heated up. I am thinking that I need some hood vents, because it holds all of that hot air in the engine bay.

[Robert B]

my one Q is how hot did you get it ?? like just a little higher or run it very close to the red on the gauge then shut it off............the fan is big as your motor is so long it has a lot of surface area and if no air flow (slow speeds and wheeling) then I know they hold a lot of heat under the hood

[carpenle]

I was almost to the red, then I shut it down to cool. When I turned arround, and was coasting down the hill, it cooled down to below half way on the gauge. Also did not heat up on the hwy driving 75-80 home.

[Hypoid]

Sounds like an airflow problem. If you are lucky, you can find the newer style fan from a '96, it plugs right in. If not, swap the old connector onto a newer fan.

The cooling system works, the same set-up is used in newer vehicles. No need to reinvent the wheel.

[Popsgarage]

I'll agree with Mike. It sounds like lack of airflow.

[carpenle]

I am hoping that fixing the aux fan will help with the air flow.

[xaza]

Aux fan is very important. Should also consider a trans cooler. New aux fan from performance radiator is only like $100 and moves more air if you ask me(plugs right in too). While you have fan off take a hose and spray water from inside out (reverse direction of airflow). You can also use a toggle switch and run aux fan constantly while wheeling, I do.

[Jim]

0.02 airflow.

I see you're mentioning elec fan, so this might not apply, but I'll recant it for kicks...

I had just purchased a 1968 Ford Ranch Wagon in San Jose California (from a nice couple on Husted Avenue). Driving down to San Diego I saw a NICE (similar vintage) hot rod car sitting on the shoulder of the slow moving, traffic clogged freeway. I stopped to ask the driver / kid what was up and he said it always works great "around home" (country - no traffic) but whenever he goes to San Diego and hits slow moving traffic it overheats. Looking under the hood I spied one missing piece of plastic and said "quite likely" your problem is the missing fan shroud (mechanical fan).

The fan shroud helps focus / force, at slow fan speeds, air THROUGH the radiator instead of curling in from between the fan blade tips and the side of the radiator.
http://www.bpeusa.com/images/BPE%20Fan%20Shroud%20small.jpg

I said he should install a shroud but in the meantime, when things get hot, kick the car into neutral and bring the RPM's up a bit. That would help force more air THROUGH the rad vs. curling in at the blade tips.

Now, you say Elec Fan (and that it wasn't turning on). Was it turning on at all?? If not, an issue to address. Second, when it does run, how air tight is the seal between the fan's shroud and the rad? If the gap is large enough to allow air to leak in from the blade tip ends instead of through the rad - a problem.

Rad fans, on my 68 (5L v8) Ranch Wagon and my 79 CJ-5 (5L v8), can be removed so long as the vehicle "generally" travels over 25/30 MPH. There will be enough ram air through the rad to keep things cool. Long stop lights - I'd just shut down the motor to not overheat. What I mean by this paragraph, is that your highway travels likely have enough ram air to keep temps down and you're relying on the fan only at slow vehicle speeds for cooling.

[carpenle]

Should also consider a trans cooler

Thanks Cliff, I do have a trans cooler. I will clean out the radiator, thanks for the suggestion. That is a good point, if I use a toggle switch, I can use the fan when needed.

[carpenle]

Hi Jim,

The Cherokee has a mech. fan, which has a shroud, and a aux. elec. fan that is turned on by a temp switch. The elec. fan is not turning on at all, so I am thinking (hoping) that is my issue. Right now as is, the mech. fan is on only half of the radiator, and other half has no fan.

[xaza]

If you are not sure it is the fan you can wire it straight to battery to be sure. The temp switch that controls fan on/off is right bat top front of engine

[Hypoid]

The temp switch that controls fan on/off is right bat top front of engine

Actually, the RENIX temp switch is in the radiator tank, on the driver's side, above the radiator hose.

http://i232.photobucket.com/albums/ee120/Hypoid/Jeep%20stuff/UPLOADS177.jpg

[xaza]

oops, completely forgot it was the old sealed system, thanks mike

[redneck23ms]

i thought the aux fan only came on when the a/c was on for the renix models. i had a base model renix mj and it didn't have the elec fan. don't think it even had the wiring for it. however i did add one on there with a swith

[Ed Gates]

I'm a 'fan' of twins myself you can get dual fan assemblies at the junk yard cheap or you can step up for about $200 and up there are lots of options and most dual fan sets flow more than your clutch fan/ aux fan set up the trick to it all is research there are fans out there that'll flow 5000cfm but draw 50+ amps of current not ideal the wiring can be tricky if you want to run the fans independently recommend, but not terribly so not to mention the horsepower gains 10-20 hp! major considerations in this project are current rating and flow rating you can even hide the extra relays in your stock relay panel if you like the clean look if you're thinking aftermarket summit racing is an awesome place to shop

[Hypoid]

i thought the aux fan only came on when the a/c was on for the renix models.The fan will come on when the thermal switch makes, or the AC pump clutch is powered up.

Good reminder! In the dead of winter, with the defroster on, the fan will run. Last time I had trouble with mine, I turned on the AC to see if the fan worked at all.

[carpenle]

I have a twin fan set up for a VW golf, but it looks like it will not fit. The xj has a pretty narrow radiator, so I am thinking of going to the JY and trying to find a working OEM part. I am also thinking that the toggle is a great idea.

[carpenle]

Here are the only two pics that I got of the run, since I had to turn back. This is where we stopped to air down, my jeep is the one with the hood up :frown:.

http://i379.photobucket.com/albums/oo233/carpenle/IMG_20130713_100817_445.jpg (http://s379.photobucket.com/user/carpenle/media/IMG_20130713_100817_445.jpg.html)http://i379.photobucket.com/albums/oo233/carpenle/IMG_20130713_100823_804.jpg (http://s379.photobucket.com/user/carpenle/media/IMG_20130713_100823_804.jpg.html)

[Mr6dwg]

The calm before the STORM!!! That road is so fun! I am doing Red Cone Sunday, with some friends from work. If somebody wants to come along, private message me and I will "get with you" on the information.

[Hypoid]

The xj has a pretty narrow radiator, so I am thinking of going to the JY and trying to find a working OEM part.Well, dammit! I took her Cherokee to the gas station last night, it started to get over-warm. I'm replacing the fan clutch first.

I'm told that a '96 and newer E-fan is quieter and moves more air. If you don't find anything that is worth bringing home, let me know. I've been known to hoard parts. :)

[carpenle]

Thanks Mike, I will let you know. Anybody need me to look for anything tomorrow?

[Hypoid]

LMAO! :D

http://www.broadwayvillagerealestate.com/wp-content/uploads/2013/05/1million.jpg

[Hypoid]

I never made time to replace my fan clutch. I did horse around with the electric fan and wiring, right before a trip up Saxon Rd.

I'll try and fill in the details this coming week...

[carpenle]

After going to two junk yards and only finding broken fans, I decided to just buy a new one from Advanced. It was about $100, but I found a $40 off $100 coupon online. Cost me $60 for a new one and they had it in stock. The JY wanted about $30, so I do not think it was too bad. I removed the AC condenser, put on the new turn signal lenses (that I found at JY), and installed the new fan. It did not seem to be switching on, so I wired it into a toggle switch in the dash, so I can control when it comes on. I also did it on a constant power, so I can run it for a min, when I shut the jeep down. We will see if it fixes the issue at the clean up run. I did however, find a spare tire for my trailer at the JY :woot: . It was sitting in the back of an XJ and it was only $35.

I thought about sending you a PM Mike to see what you had, but decided Advanced was not too bad with the coupon.

[Rick]

nice!!! Look fwd to meeting you Sat.

[carpenle]

I did a rad. flush, tstat, new hoses, and new rad. cap and I am hoping not to have any futher issues. We will see going up to the clean up run sat.

[Tom]

I did a rad. flush, tstat, new hoses, and new rad. cap and I am hoping not to have any futher issues. We will see going up to the clean up run sat.
Sounds like that only leaves the water pump, so not fixed you know where to look next. That said, hope its fixed.

[carpenle]

Jeep did great on the clean up run and did not overheat! Thanks to everyone for your help on the issue. Putting the fan on a toggle was one of the best things that I did (thanks Cliff).

[glacierpaul]

It did great Sat. Levi, good job:thumb:

[xaza]

Glad to hear it did good. How did you wire up toggle switch?

[carpenle]

I wired it to the battery with an inline fuse. I wanted to be able to leave the fan on when I turned the motor off. The toggle is on the driver side dash by the fog light switch. I cut the connection off at the JY, so it was really easy.

[carpenle]

Look at what the recovery fairy brought the XJ for my Birthday (ARB bumper and XRC8 winch):D

http://i379.photobucket.com/albums/oo233/carpenle/1990%20XJ/IMG_20130806_082850_140.jpg (http://s379.photobucket.com/user/carpenle/media/1990%20XJ/IMG_20130806_082850_140.jpg.html)

[Rick]

that looks Great!!!!! Congrats!!:2thumbup:

[Jim]

Yes, it does look nice.

Perhaps I missed it in the thread - did you get your overheating issue sorted?

[xaza]

sweet congrats!

[carpenle]

did you get your overheating issue sorted?

Yep got it all fixed up. Put a new elec. fan, rad. flush, new hoses, rad. cap, and a t stat. Did not have any issues on the clean up run, so I think I am good to go.

[carpenle]

I forgot to mention that the winch came with synthetic line. This was great, because you have to mount the winch in the arb bumper first, and then install the bumper. The whole setup was pretty heavy, I can't imagine with steel cable. Because I got the bumper used, it took some time to get it installed. I did not have directions, mounts were a little tweaked, and the bumper was a little tweaked. Like in all my mechanic work, get a bigger hammer and it is all taken care of.
:cheers:

[Rick]

get a bigger hammer and it is all taken care of.:thunb:

[carpenle]

Have done a couple trips now with the jeep and have not had another issue. Knok on wood, I think it is fixed.

[xaza]

:thumb: