Overheat
07-15-2012, 06:04 PM
#16
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Year: 1998
Model: Cherokee
Engine: 4.0L HO
Yes I have tried the ideas given and more below is a list of what I have done.
Ok so I replaced Everything under the hood that I can think of here is what I installed.
3 row CSF radiator from radiator barn
Hesco hi flow water pump
Hesco hi flow thermostat housing
OEM 195 tstat
upper and lower hoses
heater control valve
heater hoses
fan clutch
serpentine belt
Radiator cap 13lbs stock and 16lb just to check
new Autometer water temp gauge
B&M trans cooler I also bypassed the radiator
Plugs cap and rotor wires and air filter.
I have also checked the compression all 6 were around 145
had a block test done no gasses in the coolant.
no water in the oil and no oil in the water
electric fan is wired to a switch which is on all the time.
I have checked under hood temps with an IR gun and all temps towards the front of the engine seem ok, its only hot back where the sending unit is and around the back of the motor. I have flushed the motor several times with chemicals and with the Prestone kit.
I had a mechanic look at it and he couldn't figure it out either. I have basically come to the conclusion I am going to drive it til it blows then replace head or motor. I really hope I can figure this out before that happens though I really can't afford to to much more.
Thanks for your help,
Mark
Ok so I replaced Everything under the hood that I can think of here is what I installed.
3 row CSF radiator from radiator barn
Hesco hi flow water pump
Hesco hi flow thermostat housing
OEM 195 tstat
upper and lower hoses
heater control valve
heater hoses
fan clutch
serpentine belt
Radiator cap 13lbs stock and 16lb just to check
new Autometer water temp gauge
B&M trans cooler I also bypassed the radiator
Plugs cap and rotor wires and air filter.
I have also checked the compression all 6 were around 145
had a block test done no gasses in the coolant.
no water in the oil and no oil in the water
electric fan is wired to a switch which is on all the time.
I have checked under hood temps with an IR gun and all temps towards the front of the engine seem ok, its only hot back where the sending unit is and around the back of the motor. I have flushed the motor several times with chemicals and with the Prestone kit.
I had a mechanic look at it and he couldn't figure it out either. I have basically come to the conclusion I am going to drive it til it blows then replace head or motor. I really hope I can figure this out before that happens though I really can't afford to to much more.
Thanks for your help,
Mark
I am at the same point. After having it looked at more closely by my mechanic, it looks as if my only solution is to get a new engine. My block is very warped and due to the intitial overheat last year, a twist is making head and manifold sealing very difficult. It will run ok for a while in town, but It cannot run where I need it the most without an efficient and pricey fix. I am about outta money here and need a reliable mode of transportation. I've got a tough choice to make here.
07-15-2012, 06:31 PM
#17
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Year: 1989
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[QUOTE=CrawlerYJ;1885206]Good. Next is the clutch fan. With car off, and keys in hand. Try to spin the fan with a quick turn. It should move but maybe 1/4-1/2". If it moves more than that, it's bad, and that your problem.
I had a similar problem last week as far as over heating. I was reading through this the other day and going over nine. You say the fan should only move up to 1/2" or 1/2 turn? I spun mine and it spun about 1/2 turn or so. But if you say 1/2", maybe mines shot.
I had a similar problem last week as far as over heating. I was reading through this the other day and going over nine. You say the fan should only move up to 1/2" or 1/2 turn? I spun mine and it spun about 1/2 turn or so. But if you say 1/2", maybe mines shot.
07-15-2012, 06:42 PM
#18
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Year: 1998
Model: Cherokee
Engine: 4.0L HO
The "spin test" is weak at best. Fan clutch performance slowly/gradually degrades from day one with time/miles. If unsure how old it is, spendy the +/-$35 for a new one.
07-15-2012, 07:06 PM
#19
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Year: 1999
Model: Cherokee
Engine: 4.0
Mark, before things get to the point of no return. Use another mechanic.
these motors are so simple to work on and there aren't many hidden things that would cause problems.
the problem is there, another set of fresh eyes might just help.
these motors are so simple to work on and there aren't many hidden things that would cause problems.
the problem is there, another set of fresh eyes might just help.
07-15-2012, 10:14 PM
#20
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Half turn meaning from 6 o'clock to 12 o'clock? If so, it's shot.
The one on my suburban is who knows how old? Maybe original (10yrs old) and it doesn't move. Our truck spun a 1/2 turn, and it was shot once we took it off. Spin test is actually a pretty good way to tell from my experience of owning 35+ cars in my life time. But, as someone else said, for $35 and your not sure, buy one (Hayden). Not a Auto Zone brand. Their barely move any air. Get the Hayden.
The one on my suburban is who knows how old? Maybe original (10yrs old) and it doesn't move. Our truck spun a 1/2 turn, and it was shot once we took it off. Spin test is actually a pretty good way to tell from my experience of owning 35+ cars in my life time. But, as someone else said, for $35 and your not sure, buy one (Hayden). Not a Auto Zone brand. Their barely move any air. Get the Hayden.
Last edited by CrawlerXJ; 07-15-2012 at 10:19 PM.
07-15-2012, 10:25 PM
#21
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Year: 1990
Model: Cherokee
Engine: 4.0
Originally Posted by CrawlerYJ
Half turn meaning from 6 o'clock to 12 o'clock? If so, it's shot.
The one on my suburban is who knows how old? Maybe original (10yrs old) and it doesn't move. Our truck spun a 1/2 turn, and it was shot once we took it off. Spin test is actually a pretty good way to tell from my experience of owning 35+ cars in my life time. But, as someone else said, for $35 and your not sure, buy one (Hayden). Not a Auto Zone brand. Their barely move any air. Get the Hayden.
The one on my suburban is who knows how old? Maybe original (10yrs old) and it doesn't move. Our truck spun a 1/2 turn, and it was shot once we took it off. Spin test is actually a pretty good way to tell from my experience of owning 35+ cars in my life time. But, as someone else said, for $35 and your not sure, buy one (Hayden). Not a Auto Zone brand. Their barely move any air. Get the Hayden.
07-16-2012, 08:04 AM
#22
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Year: 1992
Model: Cherokee
Engine: 4.0
My temps get up to the 235-240 sometimes 250 range. I really dont think it is the fan clutch due to the fact it runs cool around town and in traffic. The only time it gets warm is on a steep grade or when off roading. I am the 5th owner of this XJ according to the carfax so who knows what she went through with the previous owners. Does anyone know of a trustworthy mechanic in the San Diego area?
07-16-2012, 11:47 AM
#23
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My temps get up to the 235-240 sometimes 250 range. I really dont think it is the fan clutch due to the fact it runs cool around town and in traffic. The only time it gets warm is on a steep grade or when off roading. I am the 5th owner of this XJ according to the carfax so who knows what she went through with the previous owners. Does anyone know of a trustworthy mechanic in the San Diego area?
Look at the radiator cap
T-stat
Coolant
Fan clutch
Those are a start. Easy to look at, replace, and are cheap.
Last edited by CrawlerXJ; 07-16-2012 at 11:50 AM.
07-16-2012, 06:11 PM
#24
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Year: 1992
Model: Cherokee
Engine: 4.0
First off Shark_Tank16 I didn't mean to jack your thread sorry about that.
You're cooking that motor. Ya, its hot under load. No, your about 2hrs from me.
Look at the radiator cap
T-stat
Coolant
Fan clutch
Those are a start. Easy to look at, replace, and are cheap.
I have replaced the cap 3 times, the thermostat 4 times from 160 to 195, the coolant has been drained countless times and the fan clutch is the stock XJ replacement from Napa.
So my question now is what is an acceptable high temp that wont ruin the motor is 240* to high?
Thanks for your help
You're cooking that motor. Ya, its hot under load. No, your about 2hrs from me.
Look at the radiator cap
T-stat
Coolant
Fan clutch
Those are a start. Easy to look at, replace, and are cheap.
I have replaced the cap 3 times, the thermostat 4 times from 160 to 195, the coolant has been drained countless times and the fan clutch is the stock XJ replacement from Napa.
So my question now is what is an acceptable high temp that wont ruin the motor is 240* to high?
Thanks for your help
07-16-2012, 06:26 PM
#25
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Year: 2000
Model: Cherokee
Engine: 4.0
The normal operating temp for the 4.0 is 200-215, with the t-stat opening at 195. I suppose hitting 240 once or twice is not going to kill the engine but at 240 the engine is in the overheat mode.
07-16-2012, 06:39 PM
#26
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Year: 1998
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Engine: 4.0L HO
The XJ uses a thermal sensitive fan clutch, not a speed sensitive clutch. The spin test does not indicate how the thermal clutch mechanism engages/disengages as it senses air temp from the radiator.
07-17-2012, 12:41 PM
#27
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07-17-2012, 12:54 PM
#28
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Year: 1998
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Not sure what u r saying, other than the spin test is reliable. I don't happen think so, some others don't think so either and the factory test method is somewhat drawn out with drilling a small hole in the shroud and inserting a thermometer to measure air temp off the rad, etc., etc., etc. In the time it takes to do the factory test method, one could probably have installed a new clutch and be reasonably sure the new fan clutch, vs a 10 year old unit, is working at peak efficiency.
07-17-2012, 02:32 PM
#29
Don't forget to make sure you fan belt is at the correct tension and that your fan shroud is in good shape.
A belt that is too loose can cause an overheat or higher than normal temps
A belt that is too loose can cause an overheat or higher than normal temps
