Hello,
I am having an issue and I could use some input. 94 Jeep XJ about 114K on her. She began to overheat last summer so I replaced the waterpump, thermostat, and new radiator and cap (16Lbs). Replaced upper and lower hoses and heater core hoses and new control valve that broke instead of letting go of friggin hose. Still had overheat issues, So I replaced fan clutch.

Under normal conditions she runs just below the 210 mark. Yet when I tow a light utility trailer with a house generator and a few coolers on it,it over heats. I am able to turn off the air conditioner and get it to back off of the red zone enough to get it home.

The only thing I haven't replaced yet is the electric fan that does come on the instant you turn on the air conditioner. Also have not replaced the heater core.

Should the Jeep be able to tow a light 5x10 utility trailer with a light load just fine? Was not pushing hard speed was below 65mph. OAT was low 90's

Also replaced the alternator (bearing rough) and new ac compressor and reciever dryer & line seals.

Thanks

 

If auto trans I'd suggest addition of Trans oil cooler. Also vereify the fins of the radiator and condenser are clear.

 

Have you checked temps with an IR thermometer?

No reason to swap e-fan if it works.

 

^Good advice above. Install a tranny cooler and you should be all set. It might be in your interests to wire a switch to the E-fan as well.

 

"Under normal conditions she runs just below the 210 mark. Yet when I tow a light utility trailer with a house generator and a few coolers on it,it over heats. I am able to turn off the air conditioner and get it to back off of the red zone enough to get it home."

I hauled a trailer load of CJ parts last week. 130-140 mile round trip(95+ air temp and some steep roads)). Mine normally runs at 210 with the a/c on at these air temps. On this trip it got hotter than I liked (1/2 way between 210 and red) but never got close to overheating even with the a/c on the whole time. All original cooling system components have been replaced (HD fan clutch) except radiator and water pump. I figure the transmission fluid temp didn't help the coolant temp at all. I just got a trans cooler yesterday and am going to replace radiator and water pump while I'm installing it.

 

Thanks fellas!
I forgot to mention I've already installed a transmission cooler (auto trans). I do have an IR thermometer. Can try that after I get home. Think my temp sensor might be giving false readings?
Is there a high flow electric fan available that might help during hot days?

Other things installed are one level heavier rear springs after discovering leaf broken. Air shocks on rear, new front rhino shocks. Other than that all stock. We don't go off road 4 wheeling. Just regular paved and dirt roads. (Directions to our house include turn off the paved road!)

 

I towed my red cherokee with my green cherokee and the temps never moved from halfway between the line in front of 210 and 210 unless I was at a red light.
Install the transmission cooler and if that does not work, maybe some hood vents .

 

Very possible. Verify temp at the thermostat housing. Where do you have your trans cooler mounted?

 

Trans cooler mounted in front of condenser on engine mounted fan side. R/H of jeep L/H fwd looking aft. Darn thing takes up 1/2 the area of radiator. I tested flow by positioning small external fan in front of grille and with jeep NOT running put hand behind radiator and flow is good, albiet not as good as side w/o cooler. I ran the lines through radiator then thru the cooler. That was what the prefered method in instructions stated. Was that wrong?

 

You don't need an auxiliary trans cooler under your conditions. There is already one built into your radiator. What you have done is restrict the cooling air going through your radiator.

What you need to do next is have your coolant checked for evidence of combustion gasses.

Doing what your Jeep is doing is one sign of a blown head gasket. Even if the test comes back negative, the head gasket could be blown between cylinders. Put a load on it, it overheats.

 

Thanks Firestorm! I didn't even think of a blown head gasket! I do have a pressure tester and found the cap leaking before. I didn't do the test after bc the cap was leaking so badly. If it dont hold pressure and there is no visible leaks.......Dangit.

 

OK fellas, what about towing in overdrive? I don't have an owners manual, and we inherited this jeep from my wife's Dad who passed about 3 yrs ago.

Anyway; I have not tried a pressure check yet it was pouring down when wife got home with the Jeep. Was talking to a guy at work who said He used to own a cherokee like mine and He had to tow his in 3rd.

Any truth to that?

 

Yes. Towing in OD is hard on the trans and will create extra heat as well. Not good!

 

It will electronically kick in and out as it needs to.

That being said, depending on load and terrain, I sometimes lock out overdrive when towing if it seems to be hunting back and forth a lot.