Ok, my 93 Jeep Cherokee (I live in AZ) recently experienced overheating issue. I did the cheapest to expensive solution.
1st, changed the radiator. Still overheating.
2nd, changed the thermostat. Got the fail safe thermostat that has the 180 degree preset. Nope...still problematic.
3rd, checked radiator for flow restriction. Input and output is constant.
4th, changed the radiator fluid and bleed the bubbles.
5th, checked the fans...both works.

There is no leak whatsoever and my reservoir is full.

Weird consistancy - In the morning, the temp stays under the 210 degree (middle) mark. No overheating.
After work or variable start up, it slowly creeps up in temp.

I have no idea what is left besides the waterpump. I don't think it should be it but I don't have a clue.

Got any advice???

 

Did you flush the coolant or drain and fill?

 

Did you replace the temp sensor?

 

Next up, water pump.

 

I drained the fluid.
No temp sensor changed.

Should I do these 2? How would it effect the gradual rise in temp?

 

That is the last choice but I don't see how it could be it...

 

You may have gunk built up and caked the passeways that ate keeping the coolant from touching the metal. Flushing it out will breakup and force it out.

You may be able to "Test" the sensor before buying one. I don't really know how to do that but I'm sure someone will chime in and tell us.

The gradual rise is most likely it just getting warmer as you drive and if it's gunked up, the coolant only cools it to a certain temp until it can't cool through the gunk anymore.

 

That would make sense but in the morning, I do not have any overheating issue when I drive to work. It only happens after work when my jeep has been under the scorching sun. Maybe there is a gunk somewhere....