Big D Squared

Ok I have a 1999 XJ and I have been having problems with my cooling system it runs hot after about 30 to 45 minutes I'm driving but not hard enough for it to be considered over over heating if you know what I mean it gets to about to 15 and then the fan kicks on and it goes back down I've changed the thermostat water pump radiator all the cooling hoses the fan clutch everything I've had the oil checked for coolant and there's no coolant in the oil or vice versa so I don't know where to go next if its just running hot is normal or if I should check something else I know that the heat hasn't worked since I've had the car so I don't know if the heater core could cause overheating problem like that but I don't know where else to turn

Cheddarnut

Well you've done all the key stuff, is it going in the red or stopping at 215?

Big D Squared

Stopping when the e fan turns on

Cheddarnut

Sorry, I missed the note about the heater core. If the heat doesn't work that is likely the culprit. You should be able to switch to heat and watch the temp drop. I would swap the core, means another coolant flush but that's not the end of the world.

Big D Squared

So if I turn on the heater now should my temperature drop when its over 210 is that what you're saying

Cheddarnut

Well 210 ish is not to high for a Cherokee, that's basically where mine runs. But yes, if the heater core is working and you over heat, you can turn the heat wide open and it sort of acts like a second radiator and brings the temp down. I'm not suggesting that as a regular feature, it's just how the system works. If you have no heat, it's likely a plugged up core, the same crud that was in your old radiator is in there too.