I have a 2000 Jeep Cherokee Classic 4L inline 6. Has 250,000 kilometers on it. Was running hot, so replaced the thermostat and did a coolant flush. Fans seem to be working. Belt seems tight. Has new plugs and new oil. and new battery. Yesterday the temps were high for this area (around 80 degrees F). The driving I do is minimal. 1/2 mile down a rough hill and 1/2 mile back up. Did that twice yesterday and on the second climb, was the temp gauge was slightly over the midline. Check gauges light came on and there was a hot smell. Oil pressure seems a bit low at 35. Not sure where to go from here. I did tow a trailer the day before down and pulled a boat out of the water to clean. Washed the salt water off after that. Didn't seem overly hot while towing.

 

Could be your cooling system needs more maintenance or parts replacement than you've done so far.

 

clutch fan might look like it is working but it is more than likely 19 yrs old don't the 2000 model suffer with head issues?

 

Yes.

Overheating is what contributes to the head issue. The head issue doesn't cause overheating until all the coolant has been bled out.

 

I'm almost sure some here have discovered head cracks without overheating. Their first indication of a problem being coolant loss. Maybe some will reply.

 

1. Check for a milkshake(coolant in oil or oil in coolant) and any loss of fluids
2. Make sure radiator isn't leaking(end tanks especially)
3. Water pump, fan clutch, and thermostat are reasons why your XJ could be overheating(Even new parts can fail)
4. Do a compression test

 

In addition to all the above, how did your coolant look when you flushed it? Your radiator may be corroded.
Is your fan shroud in-tacked? It is a critical part.
Hood insulation blanket is there for a reason too. Is it in-tacked?
Fan clutch should be looked at, make sure it’s operating properly.

 

Even after doing a new rad, water pump, hoses and flush, it wasn't until I put a new fan clutch that temps stayed stable on my '96 with 130k miles.

 

Agreed, it's only like $25, replace it. It's toast, mine was even after appearing "ok"

 

Overheating at low speeds=airflow issue. Worn out Fan Clutch or clogged fins in radiator, or ac condenser, missing or busted up fan shroud, worn out e-fan.

High speed (highway) overheating is typically waterflow issue. Waterpump, clogged radiator. messed up thermostat. Stuff like that.

As mentioned previously I'd guess fan clutch as well, based of your symptoms and description.

 

I just made the spring adjustment to my fan clutch you can really only move the spring in one direction of any significant distance. The correct direction is Counter Clockwise .
This is the starting point for the spring on the clutch as delivered can see the tab on the end of the spring that we will be moving, at the 12 o'clock position. If you try to move it Clockwise, you'll just get it to the end of the locating tab at about the 12:30 position before the valve to which it is attached, stops moving. This is the wrong direction.
This change is supposed to change the fan clutch engagement point from 210 degrees (F), to a lower temp that appears to result in 180 degree (F) operating temps.

I might add that some of the fan clutches like mine do not have a second notch as shown above. In that case continue to rotate it c/c/w pass the bottom flange and let it rest on the flange it self. That's what I did and noticed an immediate difference in temperature. The temperature seemed to stay low longer, about 170 deg. then after putting around town, the temp never went above 198 deg.

 

The only time I had an over heating issue was similar to your symptoms. It was the overflow line from the radiator neck to overflow bottle. I have an aftermarket radiator. The line was leaking where it attaches to the radiator. Engine would heat up, coolant would blow out the hole, then instead of sucking coolant back in it would suck some of the coolant from the bottle and spray it all over the engine. I kept refilling the overflow bottle until I figured it out and got to O'Reilly for a replacement line. Beefier hose with better clamps, high pressure fuel line clamps. Less than $15 total iirc.

 

The 2000 WJ 4.0 only has an electric fan unless it's a tow package, then it might have a clutch fan as well. I'd guess it's a plugged radiator.

 

All the above suggestions are good ones and hopefully something simple will solve your problem. However, the 2000 & 2001 have heads (0331 casting) that are prone to developing a crack between cylinders 3 & 4, especially if overheated, or sometimes just because of the poor casting. You will find a ton of info on this forum and others if you search. You do not necessarily have to experience overheating to first detect a head crack. Slow coolant loss or signs of coolant in the oil are possible symptoms. I found mine when an oil analysis detected antifreeze components in the oil.

One way a head crack will show up as overheating is that hot combustion gas is introduced into the cooling system and overheats the coolant. A combustion gas/block tester can detect this. They are available to loan at major auto parts stores. Sometimes a cooling system leak tester will show it.

 

Hey, CP13, what did you find? I just noticed that you first posted here on 8/5/19 and have not posted since.

The rule on this Forum is that after you post a problem and the great, experienced members here provide help you have to provide information back so that others can learn from your problems & findings. (I just made up that rule, but it seems like a good one! )