99 Cherokee sport overheating when towing

goldjeep · #1 (**permalink**) 03-30-2008, 12:20 AM

Hi. I am new, and trying to decide if I should give up pulling my horse trailer with my 99 Cherokee Sport for a few years. When it overheats, I usually pull over and run the heater until the engine cools down. I went to Vegas with two horses and had to go 30mph up the grade. I got some wetter water and ran the heater on each grade all the way home. Then I had the thermostat replaced along with a new radiator cap. Hip Hip hooray I towed for the first time without overheating. Then two weeks ago, she was getting hot, but the heater would not work. Being a blonde 50 yr old woman, I didn't know that meant I was out of coolant. So, a quick call to a repair shop who told me I had to stop and cool and put water in the radiator. I pulled over and put some water in my overflow, took the trailer off, and then had to start up to move it off....... Low and behold, the heat started coming through and temp went back down.

But the question is, where did the coolant go? I have seen her drip before, but not this time. I haven't towed since, but the temp is now running nice and under 210 a lot of the time.

I spoke to a radiator guy who thinks he could put in an aluminum radiator to help keep the engine cool. Should I pursue this or go buy a Chevy? Oh, I have 107,000 miles.

Bounty__Hunter · #2 (**permalink**) 04-01-2008, 09:09 PM

You don't need an aluminum radiator, oem replacement should be fine.

Do you have an external transmission cooler? If not, it's tranny heat that is likely causing you to overheat. This same heat will shorten the life of your tranny.

Here's a chart that will give you an idea how much longer an auto tranny will last if you can keep the heat down. A good tranny temp guage would work well too.

goldjeep · #3 (**permalink**) 04-01-2008, 11:36 PM

Thank you very much for the information. I sure appreciate your reply.

I did have the aluminum radiator installed and the engine is 10 degrees cooler now. I googled external transmission cooler and that makes a lot of sense. What type of garage would be able to put one on my jeep?

I passed on the Chevy I was looking at.

Bounty__Hunter · #4 (**permalink**) 04-05-2008, 08:58 PM

Any decent mechanic's shop should be able to install it, and not too hard for an average shadetree mechanic to install as well.

RV shops likely have a lot of experience with them as well.

I would recommend having a temp guage installed in the tranny output line at the same time as the external cooler install.