What is the optimal temp a 4.0 should run

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Apr 26, 2013 | 11:30 AM
  #1  
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

What is the optimal temp a 4.0 should run-image-2587445165.jpg  

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Apr 26, 2013 | 11:35 AM
  #2  
Mine always sits a smidge below 210.

IMO, your's is a little warm.

Have you replaced the thermostat and flushed the cooling system lately?
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Apr 26, 2013 | 11:39 AM
  #3  
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.
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Apr 26, 2013 | 11:48 AM
  #4  
Mine always runs at 180, gets up to almost 200 though if I'm sitting in traffic.
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Apr 26, 2013 | 11:51 AM
  #5  
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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Apr 26, 2013 | 11:52 AM
  #6  
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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Apr 26, 2013 | 11:56 AM
  #7  
Air in the system?
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Apr 26, 2013 | 11:56 AM
  #8  
Quote: 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
Does the electric fan kick on when your AC goes on?
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Apr 26, 2013 | 11:57 AM
  #9  
My mustang in the summer mouths runs hotter then I like when in traffic.Ive added some red line coolant additive in it.Ive notice it drop the temp about 5 deg.
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Apr 26, 2013 | 12:07 PM
  #10  
Elec Fan is on all the time . And the sensor seems right as it hot as hell . Hood is hot to open and smells
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Apr 26, 2013 | 01:18 PM
  #11  
Radiator?
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Apr 26, 2013 | 03:07 PM
  #12  
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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Apr 26, 2013 | 03:24 PM
  #13  
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).
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Apr 26, 2013 | 03:57 PM
  #14  
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

What is the optimal temp a 4.0 should run-image-3260710093.jpg   What is the optimal temp a 4.0 should run-image-891286277.jpg  

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Apr 26, 2013 | 05:43 PM
  #15  
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.
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