Dazza

Hi All.
Very new to this forum and also to Jeep ownership. But I'm hoping some of the experienced Jeepers can help me with a few problems.
I've a 97 Cherokee, (given to me by my father who had it since new) has been a wonderful workhorse for him, but recently upon towing a caravan, started overheating. I noticed that it also did it not under load when going up steep hills on highways etc.
We checked thermostat, all ok, but replaced it anyway, Water pump seems to be pumping okay.
So we can't pinpoint the problem causing to overheat. Drives fine on flat low gradient hills, but towing or under load will overheat.

Also noticed on a weekend trip that going up hills she tends to change gear up and down more often than is required. (its an auto of course), could this be a problem with the tranny? I am going to change the trans oil this week, but the gear changing didn't seem quite right this weekend.

Any help I would be so grateful as it's a great car and we want to keep it a while. And I want to leave love and blessings to you all for a wonderful and merry Christmas.
regards
Dazza
Victoria, Australia

letsgomuddin

First off, welcome to the forum! Secondly, there are a number of possible causes for the overheating. Could be a plugged radiator, bad mechanical fan clutch, bad electric fan motor or just a bad temp sensor sending incorrect readings to the temp gauge. The temp sensor is the backbone of the fuel injection system and if it is faulty, everything from fuel mixture to shifting will be out of whack. Start by checking to make sure that sensor is working properly.

Radi

Have your father drive it again and see if the transmission shifting feels normal. He should be familiar with it.
The AW4 isn't the most refined transmission out there, it does occasionally shift at oddball times. It's always felt to me as though they never cleaned up the programming for the TCU, lol. Mine upshifts when you'd expect it would hold the current gear sometimes. It's a normal quirk.

That said, there are things that can foul up the shifting...the TPS is probably the most common culprit.

Dazza

Hey thank you guys. that gives me a good starting point to get to the root of the problem. I'm in a small coastal town in Oz and the mechanics mostly only work on most popular cars so this will give me a head start.

All the best and thanks again

Dazza

belvedere

Start with a good cooling system flush.

xjsnake

Remember not to tow in Overdrive. Sounds like you are heating up your transmission too much when it's under a load and it's pumping the heat into your radiator via the transmission 'cooler' that's part of the radiator on the drivers (LHD) side. If you are going to be doing any regular towing, plumb in an auxiliary transmission cooler (tons of writeups available here on how to do that).

Dazza

Thank you both for the suggestions. I haven't noticed an overdrive button or switch, am I having a man look or are they not on every model? If so, where would it be situated?

belvedere

Just put the shift lever in 3.

playbass

Yeah, don't drive up long steep hills or tow in overdrive (the gear labeled d with a circle around it.) Your transmission shifts too much, causing it to overheat (and possibly your engine too as you found out.) I did this driving up a mountain once and overheated, was informed to keep it in 3rd when going up long hills and haven't overheated again.

Dazza

Ahh that's awesome Playbass and belvedere. thank you so much for taking the time to help me. So appreciative.