4wheeldrivenewbie

I noticed my aux fan wasnt kicking on one day when the motor was getting hot so i replaced a sensor a coolant sensor after testing the fan by hot wire jumping it.

It was working so i assumed

the temp sensor was bad which was the one on the radiator.

I replaced the thermostat also to a 195 balanced.

Still the fan does not kick on till this day and jeep gets hot. The part said it was for renualt and also fits Jeep cherokee 89 it might not have been oem. Maybe thats my problem???

Either that or my water pump is bad???? Seems like it over heats more so when it sits idlng. Maybe my radiator needs to be flushed???

My dad trying pulling his 4wheelers and 10 mins down the road almost redlined at gas station.

Beeg997

I would check some fuses for starters, and do a coolant flush, if its still happening it could be a water pump and usually when those are bad the top of the radiator will be hot while the bottom remains cold.

For the time being you could run no thermostat and that'll help it run colder. And just to let you know it gets hotter at idle because your fan isnt working and you arent moving so air isnt flowing thru the radiator

cruiser54

There is a relay for the fan. Try this. Unplug your sensor. On the engine harness side, use a paper clip to make contact between the two terminals in the plug. With key on, the fan should come on. If not, it's not the sensor and it's something else.

FWIW, overheating at a stop is generally a faulty fan clutch.

Caish

Just flushing a radiator is not enough to clean one out it its crusted inside.
I had heat issues with the 95' and I never did get it lined out, after replacing the radiator, 180* thermostat, and more.
Then my mom borrowed it and got it hot for the last time, I'm sure now it had a cracked head, it got hot enough to nearly seize up on her, and we towed it home. Two weeks later I tried to start it again and it started but ran on 5 cylinders.
Its now time for a head and overhaul because of it.

Only weakness on the 4.0 engine is cracked heads from someone getting them hot.

4wheeldrivenewbie

Thats what we did we jumped the fan at the relay and it was spinning.

So we figured it was the sensor on the radiator replaced it and the fan did not kick on jeep just got hot no fan wasted 50 bucks on a sensor that prolly wasnt even bad.

Im gonna pickup a new water pump and a coolant fan sensor and try poping that in it.

I got a 170 mile drive for the holiday i was hoping to beable to drive it and show the owner its still ticking. Well it dont tick or knock but u know things been overhauled just got a sticker on it

cruiser54

Don't jump the fan at the relay. Jump it at the sensor connector on the harness side as I described. Then, if the fan comes on, you know it's the sensor that's bad.

4wheeldrivenewbie

Well ill look into that.

Once i notice the temp gauge start going past the middle about a qaurter of an inch i usaully shut it off only went way up to redline with trailer on it.

cruiser54

Still probably a bad fan clutch that is the real issue.

4wheeldrivenewbie

I drove it was cool on the hiway got to a traffic jam at a toll and it was climbing got almost to red.

So much pressure it blew a slight hole in the radiator other day once we got going again it cooled back down.

Well ill look into the clutch fan check into it.

cruiser54

Sounds like possibly a radiator and fan clutch. Overheating in Maine in November is not good.

xjchop

The coolant temp sensor for the aux fan has to be set. You cannot just screw it in, plug in the connector and drive off. Crappy design that has to be tuned to each motor.

Illuminator

My aux fan wasn't working and I replaced the relay and it works now. Without that fan it would get real hot while sitting, now if it gets warm enough to cut fan on it cools it right back down.

89Laredo

Absolutely not true...

cruiser54

Huh? Where did you hear this? Absolutely not true.

4wheeldrivenewbie

Of course not and i wasted my time thinking i should check it. the Thing just senses coolant temp no matter how far in the radiator its screwed in.

obviously not enough the coolant would be leaking out. the coolant should still hit it.

And umm yeah ived jumped at the relay made it kick it worked so the relay appears good the fan turned on.