cherokeesteve

I had that same problem with mine, but I eventually rebuild the engine, replaced the radiator, and hoses and flushed the cooling system real good.
I think these Jeep engines have a problem with rust build up inside the engine, saw this years ago on some other car manufacture when I was working in a rebuiling shop.
Something about the way they are cast at the factory, it leaves a lot of cast iron slag inside the block that rusts real easy.
I would suggest you just flush it real good a few times and use some anti rust additive in the cooling system.

alaska xj

I've had to deal with the smae problem when I bought my jeep this spring. The Rust Flakes, I assume thats what they are, clogged by petcock on the radiator so I had to drain it using the lower hose, and when I got the hose lose I looked inside and realized that the whole inside of the hose was lined with the crap. I flushed my system real good and then filled it with water and cleaner, drove it for about an hour and then flushed it again, replaced all the radiator and heater hoses as well as the T'stat and filled it with fluid and more cleaner and drove it to work that week, then flushed it again the next weekend and once more a couple months later. It took some time to rid the system of all that gunk and ultimately it took its toll on my water pump cause that went bad a couple months ago so I flushed my system again when I changed my pump and now I got the good green stuff back every time I open the cap.

INDIANA-XJ

I noticed a similar color a while back when I took off my radiator cap. I drained the radiator and filled it again and then let it run for a bit. I then removed the resevoir tank and cleaned it thoroughly, it had some build up in the bottom. It was not as bad so I did it a couple more times then had my system flushed at a shop in town. They said they see this from time to time in these Jeeps and after a couple flushings it clears up for the most part. They also said it is more likely to happen if the vehicle is not driven a lot or has been setting for sometime. Mine has no leaks anywhere of oil, antifreeze etc.

alpine.adrenaline

I would think that if someone had poured some radiator leak sealer in there you would have seen it when you drained it last fall. If you're sure no one else has serviced your cooling system (if someone made my AF look like that I'd force feed it to them) and after you flush and refill the sludge comes back, you must have a leaking head gasket. Depending on the pressures, you may not notice antifreeze going into the oil, rather oil only being forced into your cooling system. Have you lost oil at all? Try filling it with just water next time and run it for a few minutes, then drain it all and see if there's anything in the water. The absence of any AF should make it easier to determine the culprit. That's nasty though... either way you need to thoroughly flush your system.

96Cherokee113

Hmm. Then I'd say just go ahead and give it a real good flush. It's your best bet for now. No use in buying a new one if you can make this one work. Flush some water through with a hose for a couple of minutes of however long it takes to run clear.

jeepgeek2002

It really looks like a blown head gasket but do what everyone said.. flush the radiator out.. or get one from a JY..
theres some stuff you can put in your coolant that will seal up any gasket issues you have..

funny acting. but i saw the stuff at oreillys for $19.99

Mark

tidalbreak

I had a similar problem but not as bad. I drained, flushed for over a half hour and cleaned the resevoir, re-filled and all is good. It looked like rusty sludge water. I don't know what the previous owner did, but I know water will cause this effect.

Baja820

Good info thanks guys.....

96Cherokee113

If you're concerned about a leak in the radiator there's a product called K-Seal meant for radiator and head gasket leaks. They sell it at some of the auto parts store for about $15 and looks like a little jug type container. Just for reference . I had a buddy that used it once to seal a head gasket and it worked great. He sold the truck a couple months later, but it was still holding up.

huntingman2706217

take it somewhere with the radiator installed that has a BG flush system or something like it... it flushed everything out in the heater core and motor and everything because it uses the waterpump to do so... they flush it while its running and the thermostat is open... pushes fresh new stuff in and old crap out... we used this machine at nissan and its freakin awesome...

huntingman2706217

and it could be a blown head gasket... there doesnt have to be coolant in the oil to be a blown head gasket... depends where the gasket fails...

Baja820

Update- Radiator shop called it has two cracks unrepairable. bought new one. installing within the hour......

Jamie57

AND?

Baja820

Hit a snag.....

Are the brass fittings for auto trans lines?...... What would happen if I tried to use this with an AX-15?

Baja820

Come on guys.... I need to get this thing back together so i can get to work tomorrow!