Overheating issues
06-28-2012 | 12:59 PM
#16
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
Could be a defective new fan clutch. We've momentarily seen 230 on the ScanGauge while stopped in traffic, 100+ ambient, on black asphalt, a/c crankin', all new cooling system....temp will quickly drop once moving. Even at 230, idiot light never even flickers.
06-28-2012 | 04:49 PM
#17
Thread Starter
Newbie
Joined: Jul 2009
Posts: 29
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Model: Cherokee
Fan shroud is good this only happens at idle with only the mechanical fan on. How do you test if fan clutch is faulty? I spin it by hand when cold and I can feel some resistance i spin it again when hot (with engine off) and I still feel some resistance can't say it is any more then when cold. Any thoughts?
06-28-2012 | 05:04 PM
#18
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
Hello I'm working on a 1990 xj and covered to a open system. I replaced the radiator with csf 2 core I also replaced the thermostat and the fan clutch. The problem that I'm having is when driving the temp stays right at 210 but at idle it creeps up slowly. I have the aux fan on a switch and will bring down the temp but my question is should the mechanical fan be enough to cool the system down at idle? Did I get a bad fan clutch (cheap one from autozone)? Could it be my water pump? Any help would be great. Thanks
Fan shroud is good this only happens at idle with only the mechanical fan on. How do you test if fan clutch is faulty? I spin it by hand when cold and I can feel some resistance i spin it again when hot (with engine off) and I still feel some resistance can't say it is any more then when cold. Any thoughts?
Last edited by djb383; 06-28-2012 at 05:07 PM.
06-28-2012 | 05:10 PM
#19
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Joined: Jun 2012
Posts: 4
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Year: 1996
Model: Cherokee
Engine: 4.0
06-28-2012 | 05:34 PM
#20
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
Any air that is NOT PULLED THRU THE RAD is wasted air, from a cooling standpoint. The shroud insures the fan pulls the max amount of air thru the rad. However, the shroud is just one key component in the cooling system.
Last edited by djb383; 06-28-2012 at 05:38 PM.
06-28-2012 | 09:45 PM
#21
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Model: Cherokee
My fan switch does override the auto function of the fan because I switched the renix closed system to a open system with a 92 rad. There is not a location on the rad for the renix sensor so right now I just have it on a manual switch. Just wanted to know if the mechanical fan should be enough to keep cool at idle because right now it doesn't but I would think it would am I missing something?
06-28-2012 | 10:28 PM
#22
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
My fan switch does override the auto function of the fan because I switched the renix closed system to a open system with a 92 rad. There is not a location on the rad for the renix sensor so right now I just have it on a manual switch. Just wanted to know if the mechanical fan should be enough to keep cool at idle because right now it doesn't but I would think it would am I missing something?
06-28-2012 | 10:41 PM
#23
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
R u running a/c? If not, I would think the OE mechanical fan and OE radiator would keep it cool enough IF all other cooling system components were up to par. If running a/c, absolutely need both fans AND all other cooling system components up to par. Is this the 1st summer with the CSF?
06-28-2012 | 11:52 PM
#24
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Model: Cherokee
Just installed everything that is why I'm questioning if everything is OK. All this is with actually off. Changed out everything except waterpump. How do you test if fan clutch is working. Thanks for all input so far
06-29-2012 | 08:33 AM
#28
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Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
06-29-2012 | 10:12 AM
#29
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
I'm thinking about trying the NAPA 272310 HD unit as an experiment. The kiddo will be home with the XJ next week from school and our 10 day forecast is 100+ each day. Those kind of ambient temps should provide for some good experimentation.
07-01-2012 | 12:45 AM
#30
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Model: Cherokee
I just took off the fan clutch and noticed the pulley the clutch attaches to slips on the belt is this normal could this explain why not enough air flow thus causing heating issues? If so how hard is it to change out? Thanks