USASiglerXJSYDNEY

Hey guys what's up
I have a 96 jeep xj that has an overheating issue now.

I've had problems with the CPS tripping the ASD so I fixed that and both o2 sensors due to codes and fuel economy. During the time of the CPS issue the truck started overheating for the past year now.

I've bought a new thermostat and tested it with boiling water. Etheline glycol the proper coolant. New radiator cap no leaks on ground. It has old caking coolant on the water pump. I've changed the belt and felt the pulley and it was smooth bearings and turned okay. I've tested the viscous fan and works just fine same as the electric fan comes on at high temp as well as the air conditioner. I've felt the top radiator hose as my Mrs revved at 3k rpm and k felt fluid flowing. I've had the top radiator hose off once and saw the small constant flow coming from the water outlet.

Do you think this issue is the radiator?

tech

I would change the water pump , I've seen water pumps go bad and just not pump enough water though the engine , next I would try flushing the radiator as good as you can . then see if that helps .

fb97xj1

Flushing might help, but caking coolant sounds pretty serious. I would replace the radiator along with the water pump. And the hoses.

USASiglerXJSYDNEY

Yeah thing about just replacing both is I don't have the money for both lol I'm in Australia and new oem radiator is 340 and water pump around 80. But I found from a friend a guy that sells aftermarket radiators for like 80 but that's if it will even fit correctly me having an import. I am an American by the way.

One instance about the water pump is the whole coasting and revving and the temperature didn't go down. That would be another water pump test wouldn't it? And another thing is when it's running hot I think the water pump starts to moan. Or there's a moan noise under the hood. Maybe just a pulley but still.

Then crosses out the Mrs on the throttle test where I felt the flow threw the top hose. Wish I could just throw parts at it as I have but needing it in a few weeks for my vacation to go offroading with the family.

BlueRidgeMark

How do you know that? Have you pulled the water pump out and looked at it?

If not, that is probably your whole problem.

dans98xj

it sounds like the water pump impeller may have rusted off. That could be the reason for caked coolant in the radiator. change the pump and flush it really well.

USASiglerXJSYDNEY

Well changed the dang water pump. It was just really dirty. Needed to be done anyways but still no hope. Recap. New rad cap new fluids no leaks new thermostat all hoses soft and cleaned and sprayed the inside where the water pump goes and threw the radiator. Filled properly and both electric and visous fan works perfectly. The only thing I have not a clue about is inside the radiator. Which costs like 200 off ebay here in Australia.

Do they just go bad?? Running 240 at 30 min idle on a 105 day with ac on. But not cold probably because the temperature. Boiled out of reservoir first idle. Filled to top full line. Second time warmed it up turned off the ac and gave some revs and sat around 225 then with ac in 240. I understand that the ac will make it run warmer..

How do radiators just go bad and blocked when it's just been clean the entire time :/

bad_idea

Deposits build up inside the cooling system. Calcium or something like that. That is why the coolant should be flushed and changed routinely. I did a quick search and came across this website. I have no experience with this product, honestly didn't read their entire page. Skimming through that site, it looks like it covers the basics of scale build up in a cooling system. Basically crap builds up on the internal cooling surfaces of the radiator and slows/stops the heat exchange process.

Another possible issue - What do the fins of the radiator look like? Pull the grille, look at the condenser (assuming you have AC) and look at the radiator fins too. I have heard of radiator fins getting caked with mud or bugs and that also affects their cooling capability. Wash condenser and radiator down with water externally to clean the fins.

Assuming the radiator doesn't leak, it should be salvageable. Flush internally and wash externally. I would suggest possibly go so far as to contact a radiator shop and see what they would charge to professionally clean the radiator considering the hassle up to this point and the cost of a replacement.