What is the optimal temp a 4.0 should run
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Joined: Jul 2011
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From: Chuluota
Year: 2001
Model: Cherokee
Engine: 4.0
My fan is wired to come on soon as key is turned to acc. When I got jeep 2 years ago I remember it running around 200. Now with AC on it sits above 210. I live in Florida and its hot. Is that a safe temp ? If not should I look into better then oem fan ? Thanks
my 96 has never passed 210 since i bought it in november. however i haven't done much offroading and it hasn't been above 70 outside here yet.
if mine started running over 210 regularly i'd probably be a bit nervous.
if mine started running over 210 regularly i'd probably be a bit nervous.
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Joined: Jul 2011
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From: Chuluota
Year: 2001
Model: Cherokee
Engine: 4.0
Yes the t stat is days old and flushed same time why new housing. Water pump is my next guess as I was typing this it just over heated . Shot to 250 and engine light came on. That or fan clutch
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Joined: Jan 2011
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From: Illinois
Year: 2005
Model: Grand Cherokee (WK)
Engine: 5.7 Hemi
I suggest getting temp gun and pointing it directly at the thermostat housing before you assume you're running hot. Temp sensors are not 100% accurate, especially if they're old.
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Joined: Jan 2011
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From: Illinois
Year: 2005
Model: Grand Cherokee (WK)
Engine: 5.7 Hemi
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From: Russellville, Arkansas
Year: 1991
Model: Cherokee
Engine: 4.0 I-6
While I have never overheated my XJ (who knows about the PO), mine used to run hot. I flushed my radiator, put in a new thermostat and coolant, did the ZJ fan clutch upgrade (was only $1 more than stock XJ fan clutch) and removed my A/C condenser(the A/C didn't work anyhow and I'm thinking OBA). Now, no matter what time of year, it stays between 195 and 210.
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Joined: May 2010
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From: Chattanooga
Year: 2001
Model: Cherokee
Engine: 4.0
Mine stays around 200 during normal operation.
210-220 after wheeling for several hours.
Mind you.. I dont even have an electrical fan (will change soon).
210-220 after wheeling for several hours.
Mind you.. I dont even have an electrical fan (will change soon).
Thread Starter
Senior Member
Joined: Jul 2011
Posts: 671
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From: Chuluota
Year: 2001
Model: Cherokee
Engine: 4.0
So I did the clutch . It's chilling just under 210 with ac on now. I wish I knew about zj before doing that as it wasn't that fun. Shroud is a pain and blades are sharp
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Joined: Mar 2013
Posts: 461
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From: Las Vegas NV.
Year: 1995
Model: Cherokee
Engine: 4.0 I6 High Output
My motor and fans are all stock.
Temp sits in middle most of the time. But when offroading it will go a bit over the middle mark maybe 220degree.
Sinvce i live in hot assss desert las vegas. I will be doing t-stat change and flush, then add new coolant and maybe water wetter.
Temp sits in middle most of the time. But when offroading it will go a bit over the middle mark maybe 220degree.
Sinvce i live in hot assss desert las vegas. I will be doing t-stat change and flush, then add new coolant and maybe water wetter.


