1999 overheating problem
04-10-2018, 04:51 PM
#1
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Model: Cherokee(SJ)
1999 overheating problem
ive checked googled and ask around. 1999 Cherokee sport with 4.0 Still unsure. Got the Jeep for free has overheating issue. So I changed the oil, changed the thermostat. Ran fine for a week. Started overheating again, so I flushed the system, changed water pump, another thermostat, and replaced head gasket which wasn’t blown but I thought it was so I just replaced it. Flushed system again and still overheating. Oil is clean but once I start burping the system eventually the coolant will start turning brownish. Is this oil getting in the coolant? Is this mean a cracked head? Cracked block? Thanks in advance for the help.
04-10-2018, 05:13 PM
#2
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Year: 1994
Model: Cherokee (XJ)
Engine: 4.0
Overheating
ive checked googled and ask around. 1999 Cherokee sport with 4.0 Still unsure. Got the Jeep for free has overheating issue. So I changed the oil, changed the thermostat. Ran fine for a week. Started overheating again, so I flushed the system, changed water pump, another thermostat, and replaced head gasket which wasn’t blown but I thought it was so I just replaced it. Flushed system again and still overheating. Oil is clean but once I start burping the system eventually the coolant will start turning brownish. Is this oil getting in the coolant? Is this mean a cracked head? Cracked block? Thanks in advance for the help.
04-10-2018, 05:17 PM
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Year: 1999
Model: Cherokee(XJ)
Engine: 4.0L I6
ive checked googled and ask around. 1999 Cherokee sport with 4.0 Still unsure. Got the Jeep for free has overheating issue. So I changed the oil, changed the thermostat. Ran fine for a week. Started overheating again, so I flushed the system, changed water pump, another thermostat, and replaced head gasket which wasn’t blown but I thought it was so I just replaced it. Flushed system again and still overheating. Oil is clean but once I start burping the system eventually the coolant will start turning brownish. Is this oil getting in the coolant? Is this mean a cracked head? Cracked block? Thanks in advance for the help.
I had a similar issue on my '99 Sport. Replaced the radiator with OEM replacement, problem immediately solved.
-T.
04-10-2018, 09:37 PM
#4
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Year: 2001
Model: Cherokee (XJ)
Engine: 4.0L
If you look at the way the radiator is made for your XJs if a few tubes are plugged you lost about haft the radiators cooling . replace the radiator and see if that changes things . let us know what you do .
04-10-2018, 11:26 PM
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Year: 1996
Model: Cherokee
Engine: 4.0L
Radiator is probably plugged up with gunk internally. It can literally take 10+ drains and refills of the radiator to clean most of it up. Sometimes the radiator can't be cleaned though.
Fan clutches are a problem point on the 4.0L.
Fan clutches are a problem point on the 4.0L.
04-11-2018, 09:48 AM
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Year: 1995
Model: Cherokee(XJ)
Engine: I6 4.0L
A lot of folks seem to have had success with the cheapo AutoZone/Advance/Spectra radiators. I would just go ahead and replace the radiator since it's relatively inexpensive and you've done all the other stuff.
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04-11-2018, 10:48 AM
#8
I had a similar issue with overheating. Would run awesome until parked and idling or going uphill. Chased that gremlin all through my cooling system replacing every part I could .. till the radiator was all that was original.. problem persisted.. spent $85 on the "deluxe" option at pepboys and poof!! problem solved .. seems the radiator should be the first part in the parts cannon for best results, not the last.. hmmph live and learn
04-11-2018, 02:07 PM
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Year: 1995
Model: Cherokee(XJ)
Engine: I6 4.0L
A bad fan clutch will cause an overheating at idle or low speeds/stop-and-go, but normal temperatures during highway driving.
There are folks that will say that you can see if it spins by hand when cold without resistence, but I think that's not a good test. My feeling on the fan clutch is that if it's in question, just replace it. A good quality new one is about $40.
04-11-2018, 02:27 PM
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I assume you flushed it with the thermostat out? Took me about 12gals of distilled water with the thermostat out to make sure it was getting through the system until the water started to run clear. Also flushed the heater core on its own to make sure that ran clear as well. XJ has 240k miles on it when I bought it so unsure of how old my radiator is but now she never overheats. If you've done everything else I would just change out the radiator like others have said.
04-11-2018, 02:30 PM
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I assume you flushed it with the thermostat out? Took me about 12gals of distilled water with the thermostat out to make sure it was getting through the system until the water started to run clear. Also flushed the heater core on its own to make sure that ran clear as well. XJ has 240k miles on it when I bought it so unsure of how old my radiator is but now she never overheats. If you've done everything else I would just change out the radiator like others have said.
yes did it with the thermostat out......
04-11-2018, 09:30 PM
#15
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Test and diagnose, don't start throwing parts at it.
Get a test kit for exhaust gasses in the coolant. Then you will know if it's a cracked head or not.
If not, next try a free fix. Dump some liquid laundry detergent or Dawn dishwashing liquid in your radiator, and run it like that for a week. Then flush it again.
Last stop is replacing parts.
Get a test kit for exhaust gasses in the coolant. Then you will know if it's a cracked head or not.
If not, next try a free fix. Dump some liquid laundry detergent or Dawn dishwashing liquid in your radiator, and run it like that for a week. Then flush it again.
Last stop is replacing parts.