Well I have an 89 cherokee with the 4.0 that over heats on me all the d**mn time but it sometimes cools down if I either down shift and or pull it out of gear and rev it up to about 2 grand? Me and my dad thinks it might be the water pump but not for sure. If any body could help me out ot would be greatly appreciated because were going to be moving in the very near future and need it to haul boxes from one house to the other. Thanks!

 

Had the same problem. Drilled a small hole in the thermostat and put a bigger cooling fan on

 

Water pump could be the problem. Pull it off and check it. While you're at it, pull the thermostat and check/replace it with a 195 degree one. Flush the cooling system thoroughly. Check the condition of your cooling fan and fan clutch. Make sure that your fan shroud is in good shape. Check your radiator and your A/C condenser and make sure that the fins aren't all bent up or clogged with debris.