..... driven/turned/spun by the crankshaft

 

[QUOTE=westikle;1450658]hi all, first post here. my girlfriends '01 cherokee sport is overheating at idle. after a little research i've learned at little something about an efan relay that goes bad. my question is, is there anyway to test this without removing the relay? i've read it's a pain to get to and she probably doesn't want to see me walking to her jeep with a 4" hole saw in my hand. i've also read something about just replacing the efan with a clutch fan. i'm not exactly clear on how that works, but somewhere i read it bolts to the water pump. i dunno any help is much appreciated.

thanks
wes

I'd check the engine coolant sensor. It sends a signal to the PCM which regulates the radiator fan relay on/off times. I don't know where it is located on your model, but it's a two wire sensor screwed into a water jacket. If your relay is good, and the fan is operational, that sensor could be bad. You can pull the fans electrical connector off and put 12v to it to make sure it's working. Also, I see some confusion as to whether or not you have a mechanical/clutch type fan. This would be a fan on your engine itself, driven by the accessory belts.

 

If you DO have a clutch fan (and I'm guessing you do) They do wear out. They operate by sucking air thru the radiator at IDLE speed, and at higher speeds,(driving along) the clutch slips, resulting in less 'drag' on the engine when it's not really needed.

 

ok sorry for the misunderstanding/ignorance. so i now i know i have a clutch fan and also an electric fan beside it. i always assumed the metal fan was belt driven because it is always on any time i pop the hood. so which one of these would be culprit for overheating at idle. it sounds on here that it is the clutch fan. i'm home now so i'm going to go outside and see what's going on.

thanks

 

The fan clutch is one of 4 main cooling system components. Radiator, water pump and t-stat r the other 3 major components. If u replace all 4 along with hoses, coolant only has to be drained/refilled once.

 

here's a quick question that will help clear things up in my head. [I]Could[I] it be the electric fan? is that what the relay controls?

 

If you have a properly functioning cooling system, you shouldn't need the electric fan. My electric fan would only kick on if the temp ever got to 218-220.

Edit: I have my electric fan wired to a fuse and toggle switch to turn on ad I please when I'm wheeling or driving slow on the beach in the soft sand with the ac on.

 

I would say no, with regard to overheat, especially this time of year. Factory standard cooling did not come with an efan.

 

i let it heat to normal temp, until then efan kicked on, the shut it off. the metal fan was easy to turn, as in, it didn't just keep spiining with a push, but i could easily turn it with one finger. clutch?

 

I went out this morning and the fan turned with the same little resistance. Am I supposed to be trying to turn the clutch and hold the fan still?

 

Sounds like the clutch to me.

 

X2.... It should be easy to turn with engine cold, warm it should be very difficult to turn.

 

it sounds like your water pump is bad, i had the same prob, when at idle i could rev up in nuetral and my temp would go down, try it and see . if your temp goes down and your fan is not on then you need a water pump, it didnt take but about 2-300 more rpm to get my temp down.

 

General, shouldn't the fan always be on, or are you referring to the efan?

 

The clutch fan will spin as long as the motor is running but just because it's spinning doesn't mean it's moving an adequate amount of air thru the rad because the clutch could be bad/weak. Replace it, it's like $35. Your XJ's efan only comes on at 218F coolant temp which is really toasty for this time of year.