kyledye25

Hopefully through picture works. But I'm sitting in a parking lot. Idling. A/c is on. And this is what the temp reads. While moving its a hair lower. I was on the highway and it was in-between the 210 mark and the skinny line there between 100 and 210. Is that not warm enough? I ask this because it seems like my gas mileage has gone down. This is after I replaced my rad with one from radiator barn.3 core all aluminium. Won't go above 210 unless I'm running it hard. I just don't know if its using a little more gas thinking its not hot enough. I aslo have my intake temperature sensor in the intake. The intake is wrapped it heat resistant tape....300 degrees. I know...kinda dumb. But I was bored. Lol. Bought a roll years ago and used very little. Any ways my other car...geo metro....had this problem when I changed the rad. Mainly in colder weather. Today its almost 90. And humid. And its running below 210. Think its perfectly fine?

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Troth

Yes that is running too cool. Who ever replaced the thermo last/ the parts store clerk may have gotten a thermo for a lower temp. easy fix if thats it. Running too hot puts extra stress on many parts, but running cooler can be worse. The piston head is not expanded to the minimum clearances that would be achieved at ~210. even a few degrees can make a difference over miles. it adds extra stress on the rings, since they have a larger gap. It cal also allow some gas/ oil to get down the cylinder walls. into the oil. this is all pretty minor, but over a bunch of miles will make a difference!

Troth

Idiling and running AC on high at 90 degrees should put your thermo around 220-230 usually. (that is not a OEM recomendation, just from experience) idiling isnt the best check for temp. running down the hwy at 55 with no ac for 20 miles would be the best baseline.

ericfx1984

also keep in mind that your stock gauge is not very accurate

93gc40

That is exactly where the last 4 Jeeps I have had ran. Now if that is significantly lower than yours ran in the past, maybe.... But not enough to affect MPG. I would look for other causes, first. What T-stat are you running? The reason to run a 3 core radiator is to help your jeep run cooler.

Troth

you would loose SOME compression if yours clearances arent at minimum... not sure how that would translate to MPG

Hoooper

If your gauge is right that is fine. That like 190-200. The new 3 row just keeps it closer to what the thermostat temp is set for

Troth

?




Follow OEM Specs: 1984-1997 owners manual says: 195 degree thermostat with 16-18 PSI Rad cap. each # in psi raises the boiling point 3 degrees. Standard water boils at 210... add in 18 PSI gives you a BP of ~ 264 degrees, add in coolant, youre looking at ~ 300

kyledye25

Well me t-stat and water pump is brand new too. Did them right before the rad.195 degree thermostat from mopar. I feel it may be fine. My dad says yes its good. But Idk if its the a/c that's bringing my mpgs down or the jeep running cooler. It runs great still. E fan is on with a/c too. Maybe that helps keep it cooler too. With out the a/c on i think it runs a little warmer.

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kyledye25

The reason I thought it running cooler and bringing mpgs down is cuz my metro when it got cold would not get up to operating temp. So gas mileage went down. I threw some card board in front of the rad and it got better. Just thought maybe it could happen to the jeep. Plus the jeep ran better when it was over 210 even tho before I was worried every time it went a.good bit over 210.

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goneboating06

My jeep runs a bit cooler then that and im getting about 20mpg's in my 89 Cherokee, and I have a whole new cooling system, and a rebuilt motor, so I'm sure your fine. FSM says 195, so by the looks of your gauge its spot on where it should be. But like said earlier it's not uncommon for the factory temp gauge to be inaccurate. I know the newer 4.0's run at 210 all day long, but the earlier year 4.0's run cooler ~195 from the factory.

Also running A/C will reduce gas Milage noticeably.... Mine usually drops 1-2 mpg's in the summer running the A/C.

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excess650

Turning the air on in a '96 turns on the electric fan as well. Your drop in mileage is more likely due to running the AC. I prefer to drive the Jeep without the AC if the temperature and humidity permit it.

kyledye25

Thanks for the info. I am perfectly fine with out the a/c. It's the wife that uses it. Lol

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kyledye25

She drives it most of the time. I drive my geo metro to work and back. Then we drive the jeep every where else. But if I'm driving and we are both in the car I only turn the a/c on if its super hot. But she will run it all the time. I am glad to here others run this cool. I'm sure its not terrible. But wanted to check. Running light to light in stop and go city traffic it runs a hair under 210. But never goes over.

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Hoooper

Sooo, the stock thermostat attempts to keep the engine running at 195? I wonder if that falls in the 190-200 range...

The raising BP doesn't mean anything, the coolant temp should be near the thermostat rating regardless.