Hello,

My 1994, Jeep Cherokee Sport 4.0 heats up during idle when it's hot outside. But then goes back to the middle while driving. Please help me to troubleshoot this problem. The fans are working fine. Here's a picture of the coolant gauge, it gets to the line right before the red if I'm idling in the heat for 10 minutes.

Thanks for your help.

 

The main cause of heating up at idle is the fan clutch is on it's way out. I would suggest starting there. This would also be a good time to change out your t-stat and hoses and give the entire cooling system a good flush.

 

As Robert states, fan clutch high on the list. Don't bother trying to go through the different "test" methods described for this fan clutch, they mean nothing. I can tell.
It's a relatively cheap part, and if not changed in the last few years, it's likely time to do so now.

 

Ok, please tell me where the fan clutch is located. If anyone has a picture that would be great or should I just try a YouTube video?

 

Could it possibly just be the Tstat?

 

That's possible. It's the quickest and easiest thing to change and won't hurt to do anyway

 

It's possible but not likely. If it was the t-stat it would get warm a lot more and not just at idle. The fan clutch is on you mechanical fan on the passenger side of the engine.

 

Ok, to clarify, The mechanical fan is the fan on the passenger side that has the belt schematic on it?

I really don't like doing work if is not necessary is there anyway I can be sure it's the fan clutch.
I do have a small leak in my radiator hose.

 

Yes, the fan that is driven by the belt (my passenger side is not yours
If it would be the thermostat, than it would have to be faulty in the sense that it would b stuck closed, or half open. In that case you would see a lot more overheating, also on highway.

That leak in your needs to be adressed as well. Where is it leaking, near the clamp/end? Upper or lower?
If its the lower and needs replacing, you will have to drain the coolant. In that case, you might as well take the opportunity to do a bit more work (mind you, for replacing the fanclutch, you don't need to drain anything).

Cooling system maintenance is one of the best investments you can do for your XJ.

 

Some excellent advice here.

To re-cap:

Find out what the leak is.

Replace the fan clutch as your symptoms, which you explained quite well BTW, point to the fan clutch. Fan clutch doesn't have a good diagnostic procedure to diagnose it and it's a high failure rate part as our Jeeps age.

 

The best way to fix your leak in your radiator is to just replaced it. You can pick one up at Auto Zone or Advanced Auto for around $100 and they come with a lifetime warranty. As for the fan clutch, Like I said in my other post All signs are pointing to the fan clutch and not the t-stat. You can pick up a new fan clutch also at Auto Zone or Advanced Auto for around $30. If you replace those two things you will have two of the main components to your cooling system taken care of.

 

I agree that it's probably the fan clutch, but the leak is a problem you KNOW you have. You need to figure that out and fix it anyway. I would say to fix your leak first and see if that fixes the temp problem, then move to the fan clutch next if it doesn't.

You have two radiator hoses, one up top and one down below. Which hose do you think is leaking, and which end?

The reason I ask is that the weep hole for the water pump is right above the engine end of the lower hose. If the water pump is going out, it will leak from that hole and drip down the hose, making it look like the hose is leaking.

She said radiator hose, although she might be mistaken as to where the leak is actually originating.

 

As others have said,

1. Find and fix the "radiator hose" leak. After that, make sure your coolant level is where it's supposed to be.

2. Replace fan clutch. I personally don't like Autozone or Advance parts. I use O'Reilly or NAPA. I don't want to have to go back in and replace cheaply made, defective-prone parts.

3. Your auxiliary electric cooling fan should come on when actual coolant temperature meets or exceeds 218*F. If your temp gauge approaches the red zone, and the electric fan is not running, something's wrong with it or a sensor.

 

Lately I've been ordering all my parts from Rock Auto when I know what I need in advance. I feel like I'm getting a lot less BS since I started that, and I've gotten a few helluva deals.

 

The fan is running fine, it kicks on appropriately.

My jeep is starting to run hot in general, even on the highway now

The lower radiator hose needs to be replaced, not exactly sure where the leak is on the hose. I will check since it might just be the clamps. It's a very small leak but I noticed it when I was changing my 02 sensor

Thanks guys, still think I need to change the fan clutch? I think I may start with the thermostat.