Jeepman659

My 96 xj is getting too hott when it's about 100 plus outside it gets above 210 when it's below 100 it seems to do it whether I'm on the freeway or not. I have the Aux fan jumped right now so it comes on with the key. Also I've done two coolant flushes myself heater core and all everything comes out clear and seems like the water comes out well while flushing and i've replaced the water pump and thermostat and housing.

RubenZ

do you have fan shroud?

tjwalker

Have you verified the temperature? Never a bad idea just to be sure you're not chasing your tail and you are getting incorrect data between the sending unit and dash temp gauge. Get a laser thermometer and point it directly at the thermostat housing of a hot engine.

If truly running warm, here are some possibilities to consider.

1. Radiator. Flushing doesn't guarantee efficient function. How old is your radiator?
2. Radiator cap
3. Shroud, fan clutch (although fan clutch usually leads to overheating at idle).

You may want to finish up your cooling system overhaul. The parts are not expensive and sounds like you could handle the labor.

Good luck and keep us updated!

MoparNJeep

New upgraded radiator on eBay are around $55. Also if you not opposed hood vents help a lot. And as mentioned mechanical fan shroud helps. Also if you want you can add the ZJ clutch for mechanical fan. Its loud but runs more often to aid in cooling and if your too low on oil can add to running hot.

Cane

before getting into hood vents you should make sure all your components work. I'm in the middle of fixing my overheating, so here's everything I've personally done/checked.

-does your aux fan come on at all, either by unplugging the connector to the coolant temp sensor on the thermostat housing, or simply when it gets over 220? you said by jumping it it works, so you might wanna check everything in between. the sensor, the fuse, the connections.

-clutch fan, have you ever replaced it or know if it has ever been replaced? it is part of all the maintenance item on your jeep, so it wouldn't hurt to replace it too.

-thermostat, does it open? does your upper radiator hose become hot/firm above 200? if you're positive it opens but don't have any flow, you might have air pockets. it was my case, so i had to bleed to coolant properly.

-coolant temp sender, in the rear of the block. have you checked if you're actually overheating or if it's a false reading? an infrared themp gun can help for this. comes in handy to check many other stuff too, so it's worth it.

-in my case i knew the water pump and radiator were fine, but those 2 are also very important items. make sure they're in working order.

if all of that checks out, you should never go above 210, even in traffic in 100 degree weather.

Jeepman659

Thank you all I'll be checking the temp With a gun after work today. And the radiator looks almost new I know the po said when I bought it two years ago he put it in that week. How exactly would I know if the thermostat is opening or not? It would overheat very quickly with it staying closed right?

Jeepman659

The radiator looks almost brand new from what I can see. I have a shroud around the mechanical fan what type of cap is recommended? And ill be borrowing a temp gun to check if it's even running hot or not.

Cane

on top of overheating really quick you won't feel any coolant in the upper hose and it will stay cold (or at least not hot enough so you burn yourself). one way i could tell my thermostat wasn't stuck close is that at highway speed my temp was fine, but in traffic or in a drive thru it would slowly creep up. will replace the clutch fan this weekend, i'm pretty sure that's my problem