XJ Cooling Help

[4xdog]

On closed system XJs, like my 1988, consistent slight overheating always tells me one of two things. If coolant level is dropping, I have a pressure leak. Without coolant loss, I've always found the most likely cause is an air pocket in the head -- this is particularly likely on my Cherokee when the thermostat housing has been fooled with. There are a number of references on the web discussing how to bleed any air in the system.

 

[OverlandZJ]

lets see...I have a 93 XJ with 220k...I am removing the taurus (2500-4500cfm) fan and re-installing the mech fan....with the 97-98 ZJ fan clutch.

The ZJ fan clutch part # 272310 -From NAPA (this is the best one)

If you dont mind me adding...

The ZJ fan clutch needs to be the NON heavy duty cooling clutch as it's 3/8"-1/2" shorter than the HD clutch. I tested this myself, i did not have the clearance from Rad with the HD clutch.

I didnt know about the 10 blade fan though, thanks for the tip.

 

[DrMoab]

This will cure your problem...
http://www.ffdynamics.com/jeepradextb1.html

I plan on it curing mine as soon as my money tree will come to fruit.

 

[alexfm]

so it only gets hot at low speeds? how is it on the hiway ?
do you have a/c, the rad may be new but if the a/c coil is plugged it aint gonna flow air, howz the water pump ? i had recently installed a 3 core rad from dpg and removed the ac coil, in town i rarely need the fan at all cuz it ran soo cool even in the summer months ,, my issue was on hiway speeds , i beileve it was caused mostly because my after market bumper completely changed the airflow, and combine that with the missing splash gaurd that everybody throws away,that is there to create that flow of air thru the engine bay
i was experimenting with some scrap sheet metal and made an air dam on the underside of the bumper, plus a new splash gaurd, and dropped my highway temps 10 degrees .

At crawl speed, it gets dangerously close to overheating, and at highway speed, it floats around 230-ish degrees, but again, thats reading off my factory water temp. gauge. I do have a/c, but it doesnt work at the moment. The previous owner disconnected the condenser when he replaced the radiator, so I need to clean out the system, so that might be the problem also. As for the water pump, I dont really know. I havent noticed anything really noticeably wrong with it.

 

[DrMoab]

Check out Kool-flow waterpumps. They build a pump for your jeep that increeses the flow rate substantially at low speeds but then decreases the flow as the RPM's come up so it doesn't over pressure your system or cause the problem where the coolant actually flows too fast through the system that it doesn't give the radiator time to cool it down. They are a little on the spendy side but I've heard they work well.

 

[BEVAN]

Can we talk about hood vents and locations too please, unless this is poaching but I think it could be pertain-ant. There is a lower pressure region on the hood closer to the windshield, a vent here is good a slow crawl speeds but at anything about 25, will suck air in and actually push back against the fan. Mounting too far in the front I have heard can also ruin things. Can we get a good location for NON crawl speeds?

ie. What vent location is best for ventilation of engine at speeds about 25mph, that takes air in and directs it in correct flow patterns

here's where I have mine...no trouble...you can see heat coming up from them on warm days.

 

[BEVAN]

If you dont mind me adding...

The ZJ fan clutch needs to be the NON heavy duty cooling clutch as it's 3/8"-1/2" shorter than the HD clutch. I tested this myself, i did not have the clearance from Rad with the HD clutch.

I didnt know about the 10 blade fan though, thanks for the tip.

Good call, I forgot to mention the max cooling fan clutch wont work. The 10 blade fan was worth the 20 bucks at the bone yard, keeps the temps more consistant at low speed.

 

[Black Dog]

Chances are, the rad is plugged, or possibly the block is full of scale.
.

Been there, got the rad replaced and its worked fine ever since.

 

[alexfm]

This will cure your problem...
http://www.ffdynamics.com/jeepradextb1.html

I plan on it curing mine as soon as my money tree will come to fruit.

I'd love one of those, but then I'd need to plant another half dozen money trees myself. :snorkel:

 

[winkosmosis]

Here is what I did.. it seems to help a little but the temperature varies so much I can't do a scientific test. It's a 10" fan and it fits perfectly. I stuck adhesive foam from Ace Hardware to the back as a gasket, which holds it in place wedged between the crossbar and radiator. I'm planning to add another one to the right side. I have noticed that the AC works better

 

[alexfm]

Good call, I forgot to mention the max cooling fan clutch wont work. The 10 blade fan was worth the 20 bucks at the bone yard, keeps the temps more consistant at low speed.

I think I will look into that 10 blade fan. Is it just the electric fan from a 2000 to 2001 XJ? Would I just replace my factory electric fan with it? Im thinking about heading out to the local pick & pull I go to, and check out the new one that just opened. Also, will I need to change any electrical connections or will the connectors from the newer model fit with mine?

 

[StumpXJ]

This will cure your problem...
http://www.ffdynamics.com/jeepradextb1.html

I plan on it curing mine as soon as my money tree will come to fruit.

Ok, that is tits.

Its now on my list, unfortunately somewhere near the bottom, but it is very cool...

~ Stump

 

[BEVAN]

I think I will look into that 10 blade fan. Is it just the electric fan from a 2000 to 2001 XJ? Would I just replace my factory electric fan with it? Im thinking about heading out to the local pick & pull I go to, and check out the new one that just opened. Also, will I need to change any electrical connections or will the connectors from the newer model fit with mine?

You will need the connector, they are different.

 

[alexfm]

You will need the connector, they are different.

Is it to much to ask for you to post a picture of it? Or maybe just the set up on your XJ?

 

[BEVAN]

yep ill take some shots later today.