I'm going to make this very long and detailed so you guys know what i'm dealing with

Bought my XJ 5-6 months ago, it had 1628xx on the clock when i got it. PO said he swapped in a 99 motor with somewhere around 80k on it. A couple things were different so i know that he didn't lie about

Anyway, after a week or 2 i realized the heat didn't work.... found out my heatercore was EXTREMELY clogged with disgusting **** (it really did look like it) and that he was running water in the cooling system. No coolant at all. Changed out the fluid etcetcetc ran some nice new coolant and everything was good.

Because of the motor swap and different sensor locations my temp gauge never worked. It was winter and everything seemed good so i didn't mind because it ran great, sort of.

Found a thread on how to fix this issue using brass fittings and extending the wire a little bit



Well it DOES work, after not seeing it ever move i was a bit excited



On my way to class the next day i noticed something



I was running a bit hot..... in stop and go highway traffic

I'm glad i fixed the temp gauge when i did, though i think its giving me misreadings and confusing my e-fan and not telling it to click on

Since the PO replaced the radiator, I can visually see it looks new the fins are straight and clean. I'm not worrying about that. My coolant level is good. My mechanical fan works and e fan used to work (still works when putting a/c or defroster on) which i'm thinking because it cooled down this week. I don't have any leaks or anything like that.

Thought i'd start off small



Got a brand new t-stat straight from jeep



Came off no problem, it looked fine to me. I didn't test it since i already had a new one



Old one on the bottom, new one on top

Threw on a new upper rad hose since my old one was starting to bulge/crack while i was at it. Refilled my coolant and burped the system. Took it for a little drive, went WOT, couldn't get it to go over 210. Turned the heat up full blast with e-fan on and it stayed at 160-170

Hopped on the highway for 10 miles and it seemed to fluctuate from 210-220

Upper rad hose feels like it has pressure, it gets HOT but i can squeeze it. Like its hot air and not coolant. What else could it be besides the water pump? I'm kind of hoping it isn't the water pump.... How hard is it to change on these cars?

To recap

96 jeep cherokee
99 engine
4.0 i6
aw4
New rad
Fresh coolant
New hoses
New t-stat
New coolant temp sensors
Runs too hot while driving
While idling it seems fine

Help

 

try jumping the relay for the e fan so its always on as long as the key is in the on position. helped keep my xj cool even on 100 degree days.

 

I don't want to ghetto it. I want it done right, thats why i've put as much time and money into my xj as i have

 

It's not ghetto it's just good security my e fan is always on just so there isn't a chance of over heating at low speeds 4 wheeling

 

sounds like issue with coolant sensors, like ecu is not reading it right, and efan not clicking on. but if its fine at idle and gets hot on the cruise I dont know what to say: if your efan doesnt work eng. temp usually allright while cruising

 

I was thinking the same thing, but this was the only solution to my temp sensor problem.

 

check your coolant temp switch. The first hot days we had this year my Jeep was running hotter then it ever has because the coolant temp switch wasn't telling the computer when to turn the e-fan on. I would change that next to see if it fixes youre problem. Its cheap and easy to change.

 

Changed it. Its brand new.

The e-fan hasn't turned on since i did that little brass fittings thing

 

I would bet that is your problem then. Put the cts back to the way it was and see if it still gets hot.

 

I have no way of telling how hot it's getting then.....
It's stupid -_

 

get a aftermarket one. It is likely your jeep was never over heating and you are causing all of your problems with this brass contraption. Try and splice the one wire into the two and see if it gives a temp reading like a newer jeep would.

 

I heard splicing wires would give the same outcome as what I did, mess with the signal to the ecu

 

How is it ghetto?? It's just pulling a relay out of the equation so you have proper cooling. And if you have a 0331 head and youre pushing those kinds of temps your engine won't last long.

 

X2

 

Get yourself a new water neck with the two threaded holes for your sensors or gauges from Hesco Inc so you can get rid of that Ghetto brass valve abortion you have there, the farther you go from the original flow of coolant the less chance for an accurute reading.http://www.hesco.us/