Do what i did on the heater core the PO put stop a leak in my system and clogged everything i disconnected both heater hoses from the engine and pour water into one of the heater hoses and the hose that you put water into blast compressed air and it clears alot of stuff just keep doing it a good amount and reverse for the other hose till it comes out clear

 

I'm not a huge fan of flushes, but in this case, I think it makes some sense. Go to the parts store and you'll find lots of options. I wouldn't use a harsh one, I like ones that are "citrus" based.

Because this cooling system was abused, you will have to replace the coolant multiple times UNTIL it stays the color of new green coolant over time.

If coolant was never changed, there is a good chance the thermostat wasn't changed either. Consider getting a new thermostat in there as well. 195 degrees only. I buy my stats from Jeep and also like the Stant SuperStat.

 

This will be the third flush and the most thorough flush yet. Last flush I replaced the thermostat. Unfortunately the gasket I made out of rtv last time must not have held bc I have a pin hole leak at the bottom of the tstat. So I am fixing that and flushing the whole system.

 

Ha dont feel bad, in my 86 ranger (2.3 Diesel Block Spec) i used pure water all year round. Yes, even in the winter time, but i flushed it every 2-3 weeks. That damn truck wouldnt die. I would recommend a Hose though. It always got crap out of mine. You could always fill it up with pure water and run it up the street and back. Then let it sit for a minute, and then let it drain and spray it out. From what ive used, using pure water and doing that trick is just about the same as using Chemicals. All the water sticks to the walls and pulls alot of gunk off. Its like the same thing as steaming a dirty microwave. Regular water will work fine for this, but i would use some distilled water instead. The tap water contains all the electron filled elements which cause rust, but that usually only hapens if you use water all the time or let it sit for a while.

 

Thank for all the help. I flushed the system this morning one at a time like you all suggested. I feel like I got all of thegunk out. Thanks again guys.

 

Just another update saw wetness below the tstat housing. Rented a pressure tester and found the water pump to be leaking. Needless to say a gallon or so of bran new coolant has been wasted.

Pulled water pump off, gasket shot (obviously) , and bearing shot. Got new water pump. Everything will be installed and running tomorrow morning, hopefully with no more leaks!!

I love XJ's!!