Why would a gauge point the same in both winter weather running the heater and summer weather running the a/c, if it wasn't "rigged" to do so? Our other 2 vehicles have temp gauges with "C" and "H" and the needles point to the middle year round just like the XJ. However, the Scangauge which reads in 1* increments shows how coolant rises/falls, depending on daily driving conditions being encountered. One of the most prevalent factors that I have observed, while using a ScanGauge since '05 in various vehicles year round, is how much ambient temp affects coolant temp.

My point is, why do most factory gauges point the same year round, if they weren't "rigged"? An aftermarket gauge, that has no reason to be designed/built "rigged", will not read the same year round, under differing driving conditions. A "rigged" temp gauge is a dealership service writer's best friend.

 

I know nothing about a "thermistor". Can they be made so that they r NOT linear, like the factory gauge is NOT linear?

 

Mine doesn't read the same yr around. Also it doesn't stay in one spot when in use. Under normal driving (not towing or pulling a steep long grade) max in the summer is 210. In the winter max is maybe a needles width (getting hi tech now) below 210. During use it never goes below what I take as 195 (got that position from a pic you posted of an OEM gauge with temp marks you put on it and now I can't find). But will climb to it's normal max (depending on the time of yr) if I'm pulling a slight grade or sitting in traffic. Soon as I'm back to normal driving it will go down to minimum.

One thing I can't tell from my gauge is when the thermostat opens. I can on our '96 Blazer. It's gauge will climb to it's max then immediately drops when the stat opens.

I found some old gauges (oil and temp) in the garage yesterday that I want to hook up. I really hope to do it soon but right now my back won't let me.

 

EZ, that's good to know yours fluctuates some.....that's better than our other 2 vehicles that never fluctuate, regardless of driving conditions.....but our ScanGauge, or just about any aftermarket temp gauge, will "tell it like it really is".

Again, I'm just trying to point out that when statements like "210 is the correct temp" or "Jeep 4.0L motors luv to run hot as 210 is where they were designed to run" r post in forums.......those kind of posts/info r just incorrect.

'bout time for a good oil thread, no?

 

You may also want to try some hood vents. They make my XJ run cooler by letting that hot air out. I live in the southwest, where today the high is predicted to be 108. Drove around the city all morning, low speed driving, and never went over 210. I found a pair of used Le baron vents on this forum's used parts section. Good luck.

 

Do u ever hear the efan run when the a/c is OFF?

 

Yea,a good oil thread would calm things right down.

Now as far as the 210 and 4.0's being designed to run hot info goes? I agree that it's incorrect.

 

I did the hood lift and removed the pad that was on it 2yrs ago. It didn't change coolant temp as far the gauge shows but definitely lowered the underhood temp which over time is hard on components.

 

Thermostat keeps heat in. The 4.0L is a very hot engine.

Not really. They're pretty basic electronics. Cruiser54 has a calibration guide in one of his albums.

 

I understand that the thermostat determines minimum temp only......but does the 4.0L in other Jeep models (with larger rads) run "very hot", as u say, in those other models as well?

 

Good thought. I mean these aren't high compression,tight toleranced,pushed to their peak hp output engines.

 

....but even a lo-po motor will run toasty, under certain driving conditions, when the rad is under sized......and ESPECIALLY when owner neglect is involved.

During the winter months the threads tend to be "my heater doesn't work"......this time of year, running hot seems to be the hot (pun) topic.

U get over to other old car forums and wha-la, running hot this time of year is popular but virtually non-existent 5-6 months from now (because they r replacing heater cores, not rads.

 

My motor is overheating. I replaced the air freshener and it's still overheating......what's up with that?

















Sorry, my bad.

 

no. it rarely ever sees 210. as aforementioned it will slightly climb in hot weather in traffic, but goes back to it's "normal" spot after a few mins of driving. when I had the 180 Tstat in it the needle on the dash rode slightly left of the hash under 210. I think the dash gauge is more accurate than you guys give it credit.

I checked the Tstat housing with the dash as it was warming up and after a drive idling. they basically mimicked each other as the temp changed. and as it sat and idled a 10* increase at the stat housing was seen on the dash. not rocket science.

 

I checked all of the dash gauges against mechanical counterparts. the temp was the only one even close. volts and oil pressure are both way off on mine.