How hot is too hot?

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dsherman26

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First camping trip with our 3200 pound travel trailer and the RAM. Watched the gauge summary since it shows coolant, oil, and transmission temperature. Was a little surprised to see coolant temperature creeping up around 230 before it would start dropping. Seems to me I read recently that there are shutters in front of the radiator that don't open until it gets up around there. Oil temperature got up around 240. Transmission stayed under 200. I'm guessing since the analog gauge stayed steady it's considered normal, but now I'm curious where the temperature gauge starts indicating that it's too hot.
 

Bike_Pilot

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I think that's normal temps. On most of these trucks the oil temp is made up (no actual temp sensor) so it's really coolant that is all that is relevant. The fan and shutters probably aren't fully open until 230.
 

ramffml

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Yes those temps are "normal", in that many of us see them (even while using T/H). However, whether those temps are "desirable", that's a different story.

I've been on a journey to reduce my temps. I did the AGS delete already, and have a 180 thermostat that will be installed shortly. I also run a very high quality 5w-30 oil.
 

BrenttheMouse

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I think that's normal temps. On most of these trucks the oil temp is made up (no actual temp sensor) so it's really coolant that is all that is relevant. The fan and shutters probably aren't fully open until 230.
If the oil temp is a made up number, where does the computer pull that number from? Does it just duplicate the coolant temp?
 
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dsherman26

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If the oil temp is a made up number, where does the computer pull that number from? Does it just duplicate the coolant temp?
It could be interpolated from the coolant temperature, knowing that if the coolant temperature is one thing, and the ambient is something else, the oil temperature could follow a predictable pattern, but a quick search shows that the 3.6 really does have an oil temperature sensor.
 

Choupique

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The diesels have a calculated oil temp, not measured. That's likely where that came from.

As far as the working temps go, 230F water is fine as long as it is under control. It modulating up and down indicates the truck is intentionally controlling for that temperature range. The engine is more efficient the hotter that it is, up to the thermal limits of the coolant and oil where things start boiling or coking and bad things happen. As long as you don't get indications that the temperature is out of control (warning lights, getting out of "normal" range, derates, etc) keep it running. Use the tow/haul mode, allow the engine speed to run high when it wants to run high, slow down a little bit, and enjoy the trip.

My old 6.0 chevrolet 2500 is still alive and kicking over 300k miles of working very hard, using conventional oil and coolant changed only after the maintenance light said to, and still doesn't burn oil. It runs between 215 and 220F water temp. Don't sweat it.
 

crash68

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The diesels have a calculated oil temp, not measured. That's likely where that came from.
To be more specific, the Cummins does not have an oil temperature or pressure sensor. The EcoDiesel does have an actual oil temperature sensor.
 
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most if not all dodge ram 1500 5.7 hemi's and some other rams have both a temp sensor and pressure sensor, the oil temp senor is located on the oil filter flange, and the pressure sensor is located on the front right side of the engine ported to the sensor
 

Dusty

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Yes, Virginia, there is an Oil Temperature Sensor on a 5.7 Hemi.

(My apologies for taking poetic license.)

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build Date: 3 June 2018. Now at 91733 miles.
 

tstein88

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First camping trip with our 3200 pound travel trailer and the RAM. Watched the gauge summary since it shows coolant, oil, and transmission temperature. Was a little surprised to see coolant temperature creeping up around 230 before it would start dropping. Seems to me I read recently that there are shutters in front of the radiator that don't open until it gets up around there. Oil temperature got up around 240. Transmission stayed under 200. I'm guessing since the analog gauge stayed steady it's considered normal, but now I'm curious where the temperature gauge starts indicating that it's too hot.
I have a 5.7 Hemi, 3.92 gears, 2016 1500. I have been trying to determine the best way to cool down my oil. It really worries me. When pulling a 3000lb trailor at 65 MPH, 80degrees outdoor temps, my oil has gotten as high as 265 degrees. I do run synthetic oil. I feel this it too hot, but what choice do I have? If anyone can recommend a way to cool down the oil. I intended to install a Derale oil cooler but it doesn't have very good reviews.
 

Choupique

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265 is pretty hot. 250 is the alarm point on many diesel engines.

It's probably designed to run up there. Oil works better when it is hot up to a point and the engine is more efficient the hotter it is, again up to a point.

Do those engines have a thermostat for the oil cooler? Is there an external cooler that could be replaced with a larger one and an aux fan? Grille shutters deactivated?
 

ramffml

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I have a 5.7 Hemi, 3.92 gears, 2016 1500. I have been trying to determine the best way to cool down my oil. It really worries me. When pulling a 3000lb trailor at 65 MPH, 80degrees outdoor temps, my oil has gotten as high as 265 degrees. I do run synthetic oil. I feel this it too hot, but what choice do I have? If anyone can recommend a way to cool down the oil. I intended to install a Derale oil cooler but it doesn't have very good reviews.

265 is nuts IMHO. Things you can do in easy-to-harder order
- remove all but two rows of slats in your active grill shutters (more airflow to the rad at all times)
- put in a 180F thermostat
- tune your fan to come on sooner
- install oil cooler

I've done the first two, and althought those by themselves won't reduce your peak temperature, they will help in that it takes longer to get there now. So if you used to see 265 peak after a 2 minute climb/grade, maybe you only reach 250 now at that same spot/load.

There have been oil coolers recommended on here, ones that come with there own thermostat. You will definitely need a cooler or at the very least tune the fan to come on sooner and I'd definitely do those first 2 as a first start.
 

Dusty

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I have a 5.7 Hemi, 3.92 gears, 2016 1500. I have been trying to determine the best way to cool down my oil. It really worries me. When pulling a 3000lb trailor at 65 MPH, 80degrees outdoor temps, my oil has gotten as high as 265 degrees. I do run synthetic oil. I feel this it too hot, but what choice do I have? If anyone can recommend a way to cool down the oil. I intended to install a Derale oil cooler but it doesn't have very good reviews.
My starting point would be to determine what the actual oil temperature is. The 265 could be erroneous. You could be chasing (ie: $$$) a non-problem.

Maybe start with an OEM oil temperature sensor and go from there. Fairly easy to replace on a 5.7.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build Date: 3 June 2018. Now at 91814 miles.
 
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