Cooling Fan Problem - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > Cooling Fan Problem

*VOTE NOW Help Metalcloak Giveaway an XJ Suspension*The Original 3/8" Ruffstuff Diff Cover!Steering and more from Ruffstuff!

Reply
Unread 03-17-2009, 01:41 PM   #1
JHV48
Registered User
 
Join Date: Jun 2008
Location: Carlsbad
Posts: 17
Cooling Fan Problem

OK, I've read all the posts on the cooling fan but still not sure if it is the relay or the fan clutch that is failing.

Symptoms: Fan runs from start up to shut down. Always turning at full speed whenever the engine is running. While driving in the mountains in snow country, I can barely get the engine to get warm enough to turn on the heater.

When engine is stone cold, I can turn the fan by hand but it is not free spinning. I can try and spin it but it will only spin maybe 1/4 turn with a hard push on my part.

Does this sound like the fan clutch is bad?

Oh, yeah, I forgot. 1996 Grand Cherokee with the 4.0 six engine.

JHV48 is offline   Reply With Quote
Unread 03-17-2009, 01:44 PM   #2
Greeeeenberg
Registered User
1997 ZJ 
 
Join Date: Dec 2008
Location: Suring, WI/ Houghton, MI (School-MTU)
Posts: 1,157
You need to tell us more about your Jeep to be sure we can diagnose it correctly. Year, motor, etc.

But from what said it sounds like the clutch fan.
__________________
97 ZJ Orvis 5.2 108K.

Michigan Tech Jeepers Member #1
Greeeeenberg is offline   Reply With Quote
Unread 03-17-2009, 01:55 PM   #3
comptiger5000
Registered User
1998 ZJ 
 
Join Date: Jan 2009
Location: Stamford, CT / Rochester, NY
Posts: 4,259
The engine should still warm up with the fan locked up. It does sound like your fan clutch has failed, but the not warming up is likely a failed thermostat. The 4.0 should run 195-200* all the time, maybe 190* if you have the heat cranked.
comptiger5000 is offline   Reply With Quote
Unread 03-17-2009, 01:58 PM   #4
Greeeeenberg
Registered User
1997 ZJ 
 
Join Date: Dec 2008
Location: Suring, WI/ Houghton, MI (School-MTU)
Posts: 1,157
Does it blow warm air out the heat vents at all???
__________________
97 ZJ Orvis 5.2 108K.

Michigan Tech Jeepers Member #1
Greeeeenberg is offline   Reply With Quote
Unread 03-17-2009, 03:17 PM   #5
JHV48
Registered User
 
Join Date: Jun 2008
Location: Carlsbad
Posts: 17
The air was barely warm, however, I was traveling 75 MPH late at night and it was about zero degrees outside.

On a 60 degree day, the engine runs about 200 degrees and there is plenty of hot air form the heater. I just happened to be heading south from Salt Lake City late one night and my wife and I froze in the cabin when it was zero degrees outside. And, with the cooling fan running at full tilt, the engine couldn't warm up. The temp gauge was barely above the quarter mark all night.

I imagine without the fan running constantly, the temp might have risen enough to warm up the cabin.

Sounds like the fan clutch doesn't it?
JHV48 is offline   Reply With Quote
Unread 03-17-2009, 03:24 PM   #6
tazimafied
Registered User
2000 WJ 
 
Join Date: Jan 2009
Location: Mojave Desert, CA
Posts: 237
Quote:
Originally Posted by JHV48 View Post
Sounds like the fan clutch doesn't it?
__________________
Because I felt like it!
tazimafied is offline   Reply With Quote
Unread 03-17-2009, 05:21 PM   #7
comptiger5000
Registered User
1998 ZJ 
 
Join Date: Jan 2009
Location: Stamford, CT / Rochester, NY
Posts: 4,259
Fan clutch, and thermostat. If the thermostat is functioning properly, until the engine reaches the thermostat temperature (195* on a stock 4.0), basically no coolant is circulated through the radiator, meaning the engine would warm up anyway. It all remains in the block. The only ways heat can be removed then are via the heater core, and heat radiating from the block (insignificant). At 75mph, there is a ton of airflow across the radiator whether the fan is on or off. Chances are, at 75mph in 0* weather, with a bad thermostat and the fan OFF, it would have been just as cold. Thermostats are fairly cheap, I'd replace it to be sure.
comptiger5000 is offline   Reply With Quote
Unread 03-17-2009, 07:57 PM   #8
JHV48
Registered User
 
Join Date: Jun 2008
Location: Carlsbad
Posts: 17
Good point. If the temp never reached the 180 degree mark for the thermostat to open (I have a 180 t-stat) and feed coolant to the radiator, then the block would have probably overheated.

I'll bet the thermostat is also stuck open so that the coolant is constantly circulating and I wouldn't have noticed it until I drove into freezing temps.

Thanks. Didn't think about the t-stat!
JHV48 is offline   Reply With Quote
Unread 04-08-2009, 09:55 AM   #9
JHV48
Registered User
 
Join Date: Jun 2008
Location: Carlsbad
Posts: 17
There was no problem. I should have simply closed off the radiator opening with cardboard like the truckers do when driving in sub freezing temps.

Now that the weather has warmed up, all is back to normal.
JHV48 is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.