Bmartee

I have a 99 Cherokee Sport and it's starting to over heat. At first glance, I noticed the cooling fan isn't kicking in. I tried replacing the relay but nothing changed. Should the next step be to replace the fan or is there another test I can do to verify it is in fact the fan?

Thanks!

Lowrange2

I seriously doubt the fan itself is bad.

The first step to to check your coolant.

Cerveja

Unplug the fan at the fan motor or the first junction thereafter and use a heavy gage wire to jumper it directly to the battery (Watch your fingers). If the fan comes on and doesn't shake like the bearings are toast, than you know the problem is someplace else. If the fan doesn't spin, the motor or bearings are probably shot and a new fan is in your future.

Bmartee

I think there may be a small leak around the thermostat housing. I have a gasket for that. Other than that, it seems like everything else is normal. Coolant levels are normal, no other leaks that I can find, although I can smell coolant from time to time. Possibly from the thermostat housing leak?

Pelican

What has been your normal operating temp on the gauge and what is it now when overheating?

Under what conditions is it overheating -- highway, idle, city traffic, etc.

Not saying this is your situation, but the last time I went through the efan not coming on scenario, I finally got an IR thermometer and found that the fan wasn't coming on because the coolant temp wasn't actually getting up to the ~118* turn on point.

Not sure about the '99 but with the earlier years, first test to see if efan is working is to turn on the A/C.

Bmartee

Typically the temp gauge reads 210, which is the needle straight up. Now it'll get a couple more notches above that. The temp actually goes up regardless of driving or idling. I still need to try jumping the fan off the battery, but if the fan works, what's the next step?

djb383

deleted

djb383

When was the last cooling system maintenance? Might be time for some XJ TLC. <$250 in parts (including a new rad) and a Saturday afternoon does the entire cooling system. Doing it all at once means 1 coolant drain/refill. Guessing at the problem/changing 1 part at a time means coolant drain/refill to change each part.

Roler

Djb is probably right here...for the $$ that you guys pay for parts, you get everything updated and be good for many miles...and summers...for a very very reasonable price. Keep your XJ from overheating is one of the best things you can ever do for it...

Bmartee

I just recently bought this Jeep. I'm a longtime Wrangler owner and had to get rid of it because I'm a dad. Wrangler's aren't the best grocery getters. Enter the Cherokee...I have the receipts and the radiator was just replaced within the last year. As of now I have a new water pump, belt, thermostat, thermo housing gasket, two gallons of coolant, and I'm probably picking up a new efan this afternoon. I've always believed if you got it torn apart, replace it all now. The Saturday afternoon may be a little harder to come by. Does this seem like too much or just right? Oh, and thanks for the help. It's been very helpful.

djb383

How about a new fan clutch?......it's vital to proper cooling.....and the fan shroud is intact/in place?

scottmphoto

You need to do a good flush. Make sure that the e-fan works. It's designed to kick on at @ 218 degrees or if the defrost or A/C is on. Make sure that your fan clutch is good. A lot of people upgrade to the ZJ fan clutch (it pulls more air). Make sure that both the radiator and A/C condenser fins aren't bent up and clear. If you have to fix a leak, might as well just replace the thermostat (195 degree). Make sure to use a very light coat of RTV on both sides of the t-stat housing gasket. You should also pull of the water pump and check to make sure it's in good shape. I'm in Arkansas and never use my A/C so I removed my condenser to get even more airflow through the radiator. I can dog mine and it hardly ever goes over 210.

Bmartee

Fan shroud is in tact. Where exactly does the fan clutch go? I've never gotten that deep into repairs so I'm not familiar with how it works. Flushing is gonna be part of that alleged Saturday afternoon repair. Removing the AC is a possibility, although my 7 year old daughter and my 67 year old mom, that lives with me, might object. This is all great info...thanks again for the help.

scottmphoto

The fan clutch is the part between the fan and the pulley on the motor. It's what lets the fan spin (or not) depending on the engine temp.

djb383

The fan clutch senses the air temp that has passed thru the rad. If the air temp is high enough, the fan clutch engages more/freewheels less, thus pulling more air thru the rad for more cooling. When sensed air temp is low enough (less cooling needed), the clutch freewheels more, making less load on the motor, thus better mpg, more power to the wheels and less fan noise. A fan clutch's performance will gradually deteriorate with time/miles.