Diesel Coolant Temp

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Plongson

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Well, the thread is all about coolant temp. Oil temperatures will ALWAYS be substantially higher than the coolant temp. I suspect the reason for the mothership specifying synthetic motor oil is because these motors DO run warmer to meet emission standards...none the less, conventional wisdom suggests 220°ish is too warm for coolant (IMO).

Now, with all that said...synthetic oils are rated and designed to run at a MUCH higher temp before they break down. Here is just some information from a quick search. Take it as you want, but new oil can run really hot before it breaks down.

Synthetics can safely handle higher operating temperatures without oxidizing (burning) or breaking down. The upper limit for most mineral-based oils is about 250 to 300 degrees F. Synthetics can take up to 450 degrees F. or higher (some as much as 700 degrees F).
 
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Tex, ya kind'a beat me to it...and I agree. What if we all are totally unaware of the design and engineering that went into this engine...Without accurate data and telemetry regarding the fluid temperature it's all a guessing game.

BUT...Lemme play the devil's advocate here. What if this engine came from the ground-up as an entirely new player for the 21st century? Clean AND efficient! It's not uncommon for machines of some form or another to run hot, and I mean REALLY hot. Providing the testing and engineering has gone into this design there is no reason to believe it will fail or fail prematurely. Now that is a HUGE leap of faith, but none the less, something to think about.

I still DO NOT like the discrepancy between to gauges to monitor a condition. It's bull shit. If it goes in it should be accurate...end of devil's advocate...lol
 

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Without accurate data and telemetry regarding the fluid temperature it's all a guessing game.

Exactly my point... Jeep needs to publish and provide the safe engine operating parameters so drivers can monitor and safely operate their vehicles within those parameters. Otherwise the gauges are useless without a benchmark to compare them to.
 
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Man, ya sure wouldn't want to mistakenly change the oil in these new rigs with plan'ol dino oil.

Sheesh...recipe for disaster.
 
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OK...here's a twist. Today when I got back to the shop, the off-road gauge showed 217°f after running errands. I thought it would be a great time to check things with an IR scanner...corrected for emissivity, the TOP radiator hose measured...wait for it...frigg'n 187°f, along with the top of the radiator and scanning everywhere I could on the motor, I found NOTHING containing coolant, that was warmer than 187°f.

So, where does that leave us? Ain't got a clue except it appears the digital read-out on the off -road gauge is full of shit and perhaps the analog is really giving us a better idea of coolant temp minus numbers.

And JFYI, my background includes along with other things a Certified Level II Infrared Thermographer. This data was taken with a FLIR IR scanner (not FLIR camera) but very accurate nonetheless.
 

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Or could the excessive temp readings be coming from the liquid cooled turbo... the temp swings are very erratic and closely mirror the amount of boost being applied by the turbo... just my hypothesis and not based on anything proven.
 
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