Overheating issue

chefdab · **Posted:** Mon Jan 30, 2006 8:26 pm

So I got stuck in a back-up today due to an accident. After about 10 to 15 minutes, I looked down and noticed the temp gauge was almost maxxed out. So I did a quick u-turn and went a different way to get around the accident. Should it have gotten that hot that fast? I've nearly overheated twice on the trail this past year. How would I know if the thermostat was bad? Or could the anti-freeze/water mix be off so it can't take the heat anymore? I'm thinking of trying a flush and fill first to see if it makes any difference. And if it is the thermostat, how difficult is it to replace? Or should I just do both?

Jeepjeepster · **Posted:** Mon Jan 30, 2006 9:05 pm

Hmm, I would start out by flushing it like you said. Ive never had my jeep over heat pulling boats in 90 degree heat or anything. Check to make sure your fan is kicking on. Turn the AC on high and open your hood to see it if kicks on. If you have the mech. fan also, make sure its good and tight when you try and turn it by hand(Make sure engine is off). The electric fan may not kick on if its really cold out even if the AC is on. If the temp goes back down when you get up to speed and only over heats when sitting still, it could be the fan, or water pump. If it does it when its going down the HW and idling then it could be the radiator or stat. Theres alot ot could be, start with the simple, flush it, check fan. Get back with us when you check it.

Skyjump136 · **Joined:** Tue Jul 05, 2005 6:50 pm **Posts:** 1633

Gone through any deep water/mud? This happens a lot to guys when it gets stuck up in the radiator. You won't be able to see it...just take a hose to it and see if mud starts pouring out of there. Make sure you hit both sides.

Cacher123 · **Posted:** Mon Jan 30, 2006 9:23 pm

Mine took like 15 minutes to hose out! Mud kept flowin and flowin...............

KJ04 · **Posted:** Mon Jan 30, 2006 9:40 pm

Open your hood, turn the air conditioner on high and watch your temp gauge. When the temp starts rising past normal look to see if the electric fan is runing.
If your electric fan is not coming on and you've been though deep muddy water on the trails it is likely your electric fan motor brushes & springs are clogged up with mud and are not making contact. This has happened to quite a few of us in the past.
Unhook the elect. connector along the top of the radiator, remove a bolt from the top of each side of the shroud, lower the shroud down a little to slip it off the lower hooks to remove it. Tap the slide clip off the fan blade to free the motor, then remove the screws on the ends of the motor to access the brushes and rear copper contacts.
Just pull the motor apart and clean with water, then reassemble it. Simple to do and only takes about 45mins.
While the shroud is out, clean the back side of the radiator really good with a garden hose.

Hope this helps ya. :wink:

grumppee · **Posted:** Mon Jan 30, 2006 10:21 pm

Just a quick tip...

Don't use a high pressure stream of water, you could damage your radiator. If you do however go to a coin operated car wash, keep some distance just to be on the safe side.

uvalax236 · **Posted:** Mon Jan 30, 2006 10:45 pm

David, check your pulley assembly for any kind of irregularitys. Check the belt as well.

ManicMechanicJoe · **Posted:** Tue Jan 31, 2006 12:17 am

if it is mud in the radiator, the safest way to clean it is to wet the mud down with a regular garden hose and then use compressed air to force it out. I did it on my KJ and had no problems.

Has the weather been below freezing in your neck of the woods? I had an overheating problem with my KJ. The previous owner was a great mechanic and ran straight water with no antifreeze in Minnesota...my radiator froze solid stopping water flow and causing the engine to over heat at highway speed in 14 degree weather. If that's the case just leave the KJ in a warm garage for a night or two (i used two space heaters) and that solved my problem.

chefdab · **Posted:** Tue Jan 31, 2006 6:34 pm

Well I took the fan off and hosed out the radiator real good. Also hosed out the fan itself. The water ran muddy for about 20 minutes till it started to clear up. I hope this does the trick. After I put it all back together, I fired it up and the fan came on right away. After a minute or so it cut off. I'll let ya'll know if I have anymore problems.

chefdab · **Posted:** Mon Feb 20, 2006 7:58 pm

So uh, yeah I had more problems. Went wheeling at Paragon this past Saturday. Made it through 1 short trail before it started overheating again. So we stopped and JeepinAl hotwired the fan to the battery since it seemed like it wasn't running otherwise. Seemed to work fine so we proceded to another trail. Just after th first hill climb, I looked down at the gauges and the temp was slowly creeping back up again. We took another look at the fan and it was spinning so slowly that you could stick your finger in it to stop it without injuring yourself. So we had to park my Jeep and catch a ride with Chris. I've got an appointment to take it to the dealer on Wednesday. If they end up replacing the fan, I'm going to try and get them to upgrade it to the heavy duty cooling fan with the extra mechanical fan on the drive pulley. I'll let you know how it turns out.

Jeepjeepster · **Posted:** Mon Feb 20, 2006 9:36 pm

Yes!! Please do. See if they change the fan out with a different electric fan with the Hd cooling. I know all about the mech fan, i just dont know if i would need to get a different electric fan if i got the mech fan. See if you can a difference in power also.

chefdab · **Posted:** Thu Feb 23, 2006 1:48 am

I went to the dealer today and they replaced the electric fan under warranty. I asked them about going to the upgraded mechanical fan and electric. They told me they couldn't just swap it in because the electric fan that comes with that package has a different wiring harness than the standard electric fan. Can someone either confirm or deny that for me? Does it specify this difference in the service manual? I was so looking forward to possibly upgrading so as not to worry about overheating again.

Jeepjeepster · **Posted:** Thu Feb 23, 2006 11:26 am

Can you not just get the mech fan and not a different elec fan?

You can buy the tranny cooler and the mech. fan here. Its cheap too.

http://www.moparsupercenter.com/

DaveKJ02 · **Posted:** Thu Feb 23, 2006 6:32 pm

chefdab wrote:

I went to the dealer today and they replaced the electric fan under warranty. I asked them about going to the upgraded mechanical fan and electric. They told me they couldn't just swap it in because the electric fan that comes with that package has a different wiring harness than the standard electric fan. Can someone either confirm or deny that for me? Does it specify this difference in the service manual? I was so looking forward to possibly upgrading so as not to worry about overheating again.

Sorry Dave-According to the '02 SM-there is only one fan motor harness. Just looks like the fan shroud is different to accomodate the mechanical fan. Sounds like more dealership BS but I suppose later years can vary.

Jeepjeepster · **Posted:** Thu Feb 23, 2006 7:39 pm

I have the bigger shroud and no mech fan, all I want is the mech fan! Theres alot of other stuff I want also.

Overheating issue

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