So I have a 99 xj and it keeps over heating I changed the thermostat and the water pump is fine what else should I do?

 

How do you know the water pump is fine?
Thermostat mopar equipment?
Did you flush the block and remove the radiator and flush that as well?
Is the outside of the radiator clear of debris?
Have you tested the mechanical fan clutch?
What is your temp on your gauge that you consider over heating?
have you verified that temp with?
mechanical fan shroud intact?
Electric fan ohms tested and working?
Upper and lower radiator hoses in good and stiff?
Any combustion gasses in the coolant system?

 

Just went thru all of this on my daughter's 99. It always ran warm compared to the other Cherokees I have owned and the temp would creep up the more I drove. The coolant system had what looked like stop leak in it but it was actually just the nasty crap that builds up over the years and miles all thru it. I replaced the thermostat and water pump first and still ran warm I put a radiator in it and Bam back to normal like all the others I have had. I would try flushing the radiator but really since they are only 100 bucks from advance or AutoZone just replace it.

 

Did you ever have it get hot enough to blow coolant out the radiator cap? That’s where my problem came about.

 

If coolant is blowing out of the cap, there is a problem. From what I understand, it should be directed into the overflow tank.

Honestly, the first step should be to flush the cooling system THOROUGHLY! Flush the entire system with distilled water a couple times and then flush the heater core by itself. After everything is flushed, consider changing the radiator, especially if it has the original radiator. Consider making sure that the thermostat functions properly, test it in a pot of boiling water. Then refill with fresh coolant.

 

Yes it got so hot on me it shut down and wouldn't restart there was coolant going everywhere. It actually blew the seal out the water pump hints why I replaced that too.