hey im having a bit of an issue. my jeep is overheating while it idles. it would cool down once i started driving at highway speeds. i just replaced the thermostat and it worked for a bit but now its back to overheating. ive noticed that its running pretty hot now while im driving at highway speeds. ive now noticed that im not getting any heat while im driving or idling. now that its getting colder here id really like to have that working pretty soon if its possible. it idles fine, right at 700-800. ive trolled through the forums on here and on NAXJA for hours now and i cant really find anything to help me. if anyone has any ideas it would be greatly appreciated
thank you for your time

 

Replace your fan clutch.

 

ok thank you. i just ordered one from Napa, should have it by friday

 

Backflush your heater core. It's probably full of gunk.

BTW, that's a separate problem from your overheating while idling, so you still need to do your fan clutch also.

 

I concur, fan clutch, if it's never been replaced it's likely toast.

You can test it by letting it get up to temp and then shut the engine off, see if you can spin the fan freely at all. If the fan spins freely even though the vehicle was fully warmed up it's toast.

 

Water pump.

 

I would start with Fan clutch like others have posted, also good time to flush the cooling system..

 

i replaced the fan clutch and i noticed that it still gets up into the red while i'm sitting at a stop light or just idling in general. does anyone have any other suggestions to what might be bad because i'm at a loss.
thank you

 

I will now concur with this since it hasn't solved the issue. Also, since you are now replacing another item, I would seriously consider doing a complete cooling system overhaul at this point, replace all hoses as well.

 

You might try testing your electric fan, but I doubt that's the issue. I agree with Roninofako. At this point I would do a complete overhaul of the cooling system: water pump, radiator, hoses (radiator and heater), 16 lb. radiator cap. I see you have already replaced the thermostat. Go with Stant or Carquest for the radiator cap (and thermostat, next time you replace it). Also backflush your heater core while you're at it.

Have you noticed any sludge in your coolant? Has your coolant been disappearing without any explained leaks?

 

thanks ill be doing that very shortly. no the coolant has been nice and green with no sludge what so ever. i have not been losing coolant at all its all normal levels and has been since i noticed my overheating problem and ive been checking it everyday. but i did notice that when i replaced the thermostat that no coolant or water came out of the hoses when i took them off and there was very little that came out of the engine block.

 

i know the electric fan works great i can hear it switch on when im at a red light because it gets very loud all of a sudden. plus ive popped the hood to check that just this morning.

 

This. Should have gone straight here first.

But before you tear into it, go online and find a nearby Amway dealer. Buy a box of SA8 laundry detergent. Throw a quarter cup in your radiator. Drive it that way for a week or two or three.

Then replace everything. You'll be putting new parts into a clean system, instead of into a gunked-up system.

 

That's hard to tell. I see a lot of people on here throw an awful lot of time and money at the wet part of their cooling system unnecessarily when they have the symptoms of a bad fan clutch. Then they're bewildered because they still have the problem. He did say he was starting to run hot on the highway, but you can't ever be sure what that exactly means because with a normal temp of 210°, sometimes people think they're overheating when they aren't.

Good advice about the Amway stuff. You can flush and flush and flush with water and never get all the crap out of the water jackets.

 

Normally I'd agree with you. Throwing parts at a problem is just not the smart thing to do.

But with these Cherokee cooling systems, it's so cheap to just replace it all in one shot, I think that's a better way to go. The peace of mind is worth it, I think.