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Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
Hello, I am new to this whole forum thing. I have a 1989 Jeep Cherokee Wagoneer with 69k original miles. When I purchased it last summer, it had been sitting for about 5 years. With that, my father in-law had to replace the fuel tank, fuel pump, injectors etc. due to the buildup in there. It’s been running and going enough for me to make my trip of 260 miles a week, but it tends to get very hot when I’m climbing up very large hills (High desert elevations). Normally, the temp gauge reads 210 when I’m just driving around on flat roads, but the hills I have to drive over get it to 265/red line. I usually don’t stop, I just turn on the heater and it cools back down to 210. It’s difficult to maintain at least 60mph uphill without putting my foot down more to make the RPMs go higher and get past the hill already. My Jeep idles really low and fluctuates a little but I don’t know if that has anything to do with it.
My father In-law has done all the work for me in getting it running good, but he is a busy man and I wanted to try and figure out this problem instead of always calling him. I am a woman, with a small knowledge of cars, and honestly, i just need help. If anyone has any idea what could be going on, or what I should replace or do, please let me know. I really appreciate it, thank you.
TLR; My Jeep is over-heating when it’s going uphill.
Hello, I am new to this whole forum thing. I have a 1989 Jeep Cherokee Wagoneer with 69k original miles. When I purchased it last summer, it had been sitting for about 5 years. With that, my father in-law had to replace the fuel tank, fuel pump, injectors etc. due to the buildup in there. It’s been running and going enough for me to make my trip of 260 miles a week, but it tends to get very hot when I’m climbing up very large hills (High desert elevations). Normally, the temp gauge reads 210 when I’m just driving around on flat roads, but the hills I have to drive over get it to 265/red line. I usually don’t stop, I just turn on the heater and it cools back down to 210. It’s difficult to maintain at least 60mph uphill without putting my foot down more to make the RPMs go higher and get past the hill already. My Jeep idles really low and fluctuates a little but I don’t know if that has anything to do with it.
My father In-law has done all the work for me in getting it running good, but he is a busy man and I wanted to try and figure out this problem instead of always calling him. I am a woman, with a small knowledge of cars, and honestly, i just need help. If anyone has any idea what could be going on, or what I should replace or do, please let me know. I really appreciate it, thank you.
TLR; My Jeep is over-heating when it’s going uphill.
First of Welcome to the forum!
Second off.......... Beautiful Jeep!
My Uncle and Aunt used to live in the Dalles. I think Susan still does?
Anyway............
Here is a place you can get a bunch of information, and down load repair manuals. The 88 would be close to the 89 so I would look in there. http://cruiser54.com/?page_id=365
First thing to look at is your radiator cap.
That is the cheapest solution at this point.
My first thought is whether the torque converter is locking up. If it's not, you're going to generate a whole lot more heat in the trans going uphill which gets dumped into the radiator. To test, when drive level at highway speeds, gently tap the brake with your left foot. You should see the rpm jump a few hundred rpm as the torque converter unlocks. The usual cause for that is the switch at the brake pedal being loose, misadjusted, or dirty inside. On an 89, it's a separate white switch high up on the brake pedal and will also have a vacuum hose connected if you have cruise control.
I would also check the throttle position sensor (TPS). On an 89, the TPS will have two connectors. The square one is for the trans computer, and the flat one is for the engine computer. A bad TPS will cause it to not downshift and may cause the torque converter to not lockup as well. It's pretty easy to test with a meter.
Original radiator? If so, good time to replace it and upgrade to the open cooling system.
In the meantime, check to see if the coolant cap on the reservoir is sealing properly. There is an upgrade for that also.
As for the drivability issues, go to my website and complete Tips 1,3,4, and 5.
My first thought is whether the torque converter is locking up. If it's not, you're going to generate a whole lot more heat in the trans going uphill which gets dumped into the radiator. To test, when drive level at highway speeds, gently tap the brake with your left foot. You should see the rpm jump a few hundred rpm as the torque converter unlocks. The usual cause for that is the switch at the brake pedal being loose, misadjusted, or dirty inside. On an 89, it's a separate white switch high up on the brake pedal and will also have a vacuum hose connected if you have cruise control.
I would also check the throttle position sensor (TPS). On an 89, the TPS will have two connectors. The square one is for the trans computer, and the flat one is for the engine computer. A bad TPS will cause it to not downshift and may cause the torque converter to not lockup as well. It's pretty easy to test with a meter.
03-23-2022, 12:45 PM
Over Heating Issues
R; My Jeep is over-heating when it’s going uphill.
