Offroad overheating

Hello guys. Im new here and new with the kj. Now i live in egypt,other side of the world and going offroad a lot. Like yesterday,went offroad,mostly soft sand and than it started to get hot. Gauge above the halve. So i quit my car and the water was boiling and no fan on. Is that normal that if the car is hot and off the fan wont work? So i let it cool down and filled it with coolant. Since than the car worked fine. Even with the ac on, checked the electrical fan with the ac on and it works fine. My question is could it be possible that the high speed of the fan doesnt work? By the way its a 2003 v6 3.7. Thank you all and hope to get some solutions

Welcome to the forum Karym.
The correct coolant is HOAT (Zerex G-05) only- is that the coolant you used?
Your temp sensor may not be read correctly if you were just using water. Use a proper mix of Hoat/Zerex. Hoat needs to be flushed every 5 years .
Boiling over ..was it water at the time or hoat coolant? Try replacing the reservoir cap proper pressurization is critical as so is a system that has no leaks. Pressure test it.
Does the high speed fans come on if you disconnect the wiring harness to the temperature sensor? The relay may need replacement & is located on fender, wires from fan go to it. BTW sand ...fans might not like and carry extra air filters and changing them frequently is important. Dont want fine sand getting into throttle body.

Hello. Thx for ur reaction. Yes, i used Hoat coolant and the electric fan works when im using the ac abd ut also comea on when i remove the harness of the sensor. What i dont understand is why the fan didnt work when i turned off the engine while it was hot :S. Also i think than my fan has only one speed. Didnt notice change in speed before and when i look at the connector of the fan i see that it has only 2 wires. To me it seems that that is only one speed than. Can that be it? Thx again

Might be a one speed. My 02 has a one speed electric but I have the HD system with the mechanical fan as well. I seem to remember something about 02-03 being one speed but not positive.

Oh the pcm reads temp and the high speed fan on my 2004 does not kick in until it really gets hot some where around 227F If I remember right..
The electric fans do not run after the jeep is turned off...It is not a Honda..LOL..
If your temp gauge is somewhere close to or just slightly above middle that is then normal running temps.
To get a real accurate reading you can plug into the OBD2 port and see the real temp reporting. I have one of these I can plug into.
Autel MaxiTrip TP-100 Link: AUTO MaxiTrip TP100 COMPUTER 4-IN-1 - US$87.00
49890[/ATTACH]"]
You can see forward water temp FWT is reporting 215F the high speed fans are not on.
Use a coolant tester & what is the boiling point and temp rating of your Hoat coolant? ..
Pressure test the system to make sure you have no leaks!

I got an OTC 9450 for about 90 bucks and it will datalog and freezeframe. Give all that sensor info live. Seems to work well for what it is. Will read ABS codes too. Supposed to do airbag codes but no luck there. Wasn't that surprised.

Karym said:

Hello guys. Im new here and new with the kj. Now i live in egypt,other side of the world and going offroad a lot. Like yesterday,went offroad,mostly soft sand and than it started to get hot. Gauge above the halve. So i quit my car and the water was boiling and no fan on. Is that normal that if the car is hot and off the fan wont work? So i let it cool down and filled it with coolant. Since than the car worked fine. Even with the ac on, checked the electrical fan with the ac on and it works fine. My question is could it be possible that the high speed of the fan doesnt work? By the way its a 2003 v6 3.7. Thank you all and hope to get some solutions

Click to expand...

Do you have both the electric fan and mechanical fan? The electrical fan you have is only 1 speed and turns on at 219 degrees(or when AC is commanded on) and the clutch fan fully locks at 230 degrees(OEM clutch).


In your heat and soft sand you should be in 4low,if not that could be your issue and/or the fan relay is going bad.Get the updated version from Chrysler only,it has a massive heat sink on it now.

How much $ is the new Chrysler one with heat sink worth now?
I've seen a photo of it looks nice and beefy,with deep ribs! Where is the BBQ sauce LOL?

Thx again. Yes i ve both. Mechanical and electrical fan. Dont know the meaning of hd cooling. What includes it? What if i ve only one speed on my electrical fan? Is it possivle to upgrade or change?

Karym said:

Thx again. Yes i ve both. Mechanical and electrical fan. Dont know the meaning of hd cooling. What includes it? What if i ve only one speed on my electrical fan? Is it possivle to upgrade or change?

Click to expand...

Since you have the mechanical and electrical fans, you have what is called Heavy Duty cooling (HD cooling.) And on the 2003 model the electrical fan has only one speed - no option to change it as far as I know. The Jeep's computer (BCM) controls the fan and it doesn't have capabilities for two speeds.

Welcome to the forum, by the way!

Bob

LibertyTC said:

How much $ is the new Chrysler one with heat sink worth now?
I've seen a photo of it looks nice and beefy,with deep ribs! Where is the BBQ sauce LOL?

Click to expand...

I paid $70 at the dealership,granted I do have a account so I pay far less.

Ok. Than what could be the problem?? 5 minutes in sand and it overheats doesnt sound normal to me. :S. Also cuz i dont have mechanical, oil and water problems.

This should be it:

http://www.factorymoparparts.com/4868332ae.html

4868332AE RADIATOR FAN RELAY

^^ for reference.

Thx all. Problem was the radiator

Even though the original poster figured out whats wrong i wanted to point this out.

Maybe it changed mid year, but my 04 doesnt have the fan relay under the battery.