Engine Oil Temps- How Hot is too Hot?

[bbslider001]

I am guessing this may have been discussed before, but as I have stated in a previous thread, I thought my oil hitting 230* while pulling a long grade with my RV in tow was not that big of a deal. I heard from some that 225-235 was a prescription for engine failure. Long story short, my oil reached 235* at one point, but never got above that. So, I changed to a cooler thermostat and changed the oil to 15w-40 from 10w-30 and it did bring it down. But, even with the 15w-40, it got to 225* and I think would have gotten to 230* had the grade been longer. So,what say you guys? Is this even a concern? I never monitored EOTs. I only paid attention to EGTs and coolant temps, so this is a little new to me. I just figured if it wasn't OH and EGTs were below 1250*, all else was good. Some seem to think this is not the case. I would definitely welcome any and all input to add to my education. On a side note, the truck performed flawlessly and never hinted at overheating, but the gauge sure seemed to think 230* was cause to put it in the red zone.

 

[dparm]

Most cars are probably running 190-210 as their normal operating temp, so 230 is nothing. I've pushed my oil temps past 250 on the track without issue, and there are others here who have seen 300.

The oil is well over 230 in certain hotspots of the engine anyway.

 

[toneydoc]

The oil is not going to do anything crazy at the temp of 235. Normal operating temp of water cooled engines are in the 210-215 range. My Harley will run oil temp of 250 or so on summer day without trying too hard. And the oil does not do anything crazy or evaporate. I suspect that HDEO you are using will handle all the long pulls you can throw its way.

 

[Ducman]

To the OP.

There's nothing to get too excited about with your situation.
There was no thermal runaway, and everything returned to normal after a while.

Also I personally would be seriously considering using a very high quality full synthetic oil I could run under the circumstances, if your oil temps are getting up that high. IMO, it pushing the friendship with anything else.
Amsoil and Mobil 1 comes to mind.

Out of curiosity.
What temp thermostat are you running now since the change, and what was it before?

 

[andyd]

Would adding an oil cooler help? Rig it with a thermostat. Overheated a few bug engines in my youth. Coolers helped them

 

[dparm]

Originally Posted By: andyd
Would adding an oil cooler help? Rig it with a thermostat. Overheated a few bug engines in my youth. Coolers helped them



It would help lower the temperatures, yes, but it's not like the OP is having sustained oil temps of 280+.

 

[Chris142]

http://m.corvetteforum.com/autocrossing-...tml?styleid=140

 

[Clevy]

Originally Posted By: dparm
Originally Posted By: andyd
Would adding an oil cooler help? Rig it with a thermostat. Overheated a few bug engines in my youth. Coolers helped them



It would help lower the temperatures, yes, but it's not like the OP is having sustained oil temps of 280+.




Exactly.
Sustained temps of 230f isn't doing any harm to the engine with any modern spec oil in a gasoline engine.
If those type temps will be the norm a shorter interval might be a prudent decision,I certainly wouldn't recommend extended drains if 235f was the norm temp.
Considering the op stated that it got that hot going uphill working the engine very hard that means it's a max oil temps and not a serious issue since it's not like it's always that hot.
I've had temps of 270f with my charger with 5w-20. Engine ran as quiet as a church mouse.

 

[bbslider001]

Originally Posted By: Ducman
To the OP.

There's nothing to get too excited about with your situation.
There was no thermal runaway, and everything returned to normal after a while.

Also I personally would be seriously considering using a very high quality full synthetic oil I could run under the circumstances, if your oil temps are getting up that high. IMO, it pushing the friendship with anything else.
Amsoil and Mobil 1 comes to mind.

Out of curiosity.
What temp thermostat are you running now since the change, and what was it before?


I had a 203* thermostat and changed it back to the 180*. Thanks for the input!

 

[bbslider001]

Originally Posted By: andyd
Would adding an oil cooler help? Rig it with a thermostat. Overheated a few bug engines in my youth. Coolers helped them


It already has a dedicated oil cooler from the factory that is pretty big and efficient. Mine was replaced 20k miles ago, so I know it flows well and works well.

 

[BituminousCoal]

I did the same thing w/ the 203º's and got rid of them. Made for rough idles on my trucks, higher temps, less precise temp control, and no better mileage. Went back to OEM motorcraft/Wahler 89ºC stat. Some who tow are using 180º, but I think that's a bit low.

However, 200º - 235ºF oil temp is normal for 7.3. My trucks have always seemed to run about 15-25º above the coolant temp - even the one w/ new oil cooler.

 

[SteveSRT8]

Originally Posted By: dparm
Most cars are probably running 190-210 as their normal operating temp, so 230 is nothing. I've pushed my oil temps past 250 on the track without issue, and there are others here who have seen 300.

The oil is well over 230 in certain hotspots of the engine anyway.


Not only has my engine seen 300 degrees hot lapping at a track event, it suffered no damage of any kind and the oil tested out fine also. Using M1 0W-40, my factory recommended oil right on the cap.

230-250 is not that hot at all, as stated there are much hotter spots!

 

[roadrunner1]

I read your first thread on this topic and now this one, I had several of those 7.3's and I don't think I had ever observed oil temp.
The temps you described are perfectly normal for newer diesels being pushed as you did. I was never a fan of running the 203f thermostat as many did, so you're back to stock now which should keep everything within factory specs.

As far as the parking lot oil change, the 10w-30 should have run cooler than 15w-40, not hotter.
I do still have an '89 IDI 7.3 that has been on 10w-30 for several years without issue. It gets loaded with gear and run down the highway and I have never thought about oil temps as its being used as it was designed at the time of build and speced 10w-30. Its a Super Duty, which is what Ford called the F550 at the time, and when I said loaded I meant loaded to capacity.

In my opinion you observed temps well within operating parameters of your 7.3.

 

[bbslider001]

Originally Posted By: Chris142
http://m.corvetteforum.com/autocrossing-...tml?styleid=140


Thanks Chris! Pretty interesting reading about the journals going out of round at those temps, yet the oil is still fine!

I am beginning to think that I panicked over nothing. My oil temps were reaching those higher temps at the top of a long, hard pull on a hot day. I was probably fine. I am just trying to get educated for future trips so I don't stress needlessly over something that isn't an issue.

 

[bbslider001]

Originally Posted By: BituminousCoal
I did the same thing w/ the 203º's and got rid of them. Made for rough idles on my trucks, higher temps, less precise temp control, and no better mileage. Went back to OEM motorcraft/Wahler 89ºC stat. Some who tow are using 180º, but I think that's a bit low.

However, 200º - 235ºF oil temp is normal for 7.3. My trucks have always seemed to run about 15-25º above the coolant temp - even the one w/ new oil cooler.


Man, I could not agree more. I changed the thermostat in December because so many were saying it was the factory temp, made for better mileage, blah, blah, blah. I noticed nothing other than a hotter coolant temp. My coolant temps now stay at the "N" or the "O". On the long pulls, after the swap, It would get to the "R", but not above. With the 203*, it would get to the "L"!!!! I was like "yeah, no thanks". I know the cooling system for the 7.3 is very efficient and my system is in great shape, so I ditched the 203*. I also live in a warm climate, so there is really no need for it. Thanks for the info! Nice to hear from a fellow 7.3 owner!

Originally Posted By: roadrunner1
I read your first thread on this topic and now this one, I had several of those 7.3's and I don't think I had ever observed oil temp.
The temps you described are perfectly normal for newer diesels being pushed as you did. I was never a fan of running the 203f thermostat as many did, so you're back to stock now which should keep everything within factory specs.

As far as the parking lot oil change, the 10w-30 should have run cooler than 15w-40, not hotter.
I do still have an '89 IDI 7.3 that has been on 10w-30 for several years without issue. It gets loaded with gear and run down the highway and I have never thought about oil temps as its being used as it was designed at the time of build and speced 10w-30. Its a Super Duty, which is what Ford called the F550 at the time, and when I said loaded I meant loaded to capacity.

In my opinion you observed temps well within operating parameters of your 7.3.


Roadrunner, thanks for the info on the 7.3! It helps my decisions going forward at this point. I am not going to stress over EOTs anymore unless they just get ridiculous. The highest though was on the really hard pull, so it seems normal. As stated above, I tried that 203* thermostat because it was touted as the "factory spec". When it got to the "L" on the first hard grade and didn't come down, I was like "yeah, no thanks".

 

[A_Harman]

When I was a development engineer at Cummins, I used to run hot box tests at rated power for hundreds of hours on engines with 230F coolant temperatures, which drove the oil temperatures to 280F on dino 15w40. We never worried about the durability. All that my management wanted to know was the exact date that the test would be completed.

 

[dnewton3]

Originally Posted By: A_Harman
When I was a development engineer at Cummins, I used to run hot box tests at rated power for hundreds of hours on engines with 230F coolant temperatures, which drove the oil temperatures to 280F on dino 15w40. We never worried about the durability. All that my management wanted to know was the exact date that the test would be completed.



Very good to hear some credible info. It coincides with much of the engine platform testing I heard about when I worked at Ford. I recall seeing the photos of the 6.8L Triton in durability testing. They ran it for 200 consequtive hours (stopping only for OCIs) at WOT against the dyno; exhaust manifolds were glowing red for the entire test. Many of these companies develop robust designs after a literal flogging of the equipment. Some of the development engineers are almost sadistic in their approach.

But for some reason the AR attitude of the typical BITOGer thinks he needs to find a "better" way ...

When it comes to the care of the equipment, there is an easy formula to follow:
1) open owner's manual
2) turn to maintenance section
3) follow directions
4) close book
5) open beverage
Are there some exceptions? Absolutely! We all know by now of the Toyota and Saturn sludgers, etc.

But the VAST majority of the equipment is well designed and well made. All we have to do is follow the instructions and quit worrying.



{sidebar question} A_Harman - did you work/live in Columbus? I have relatives in the area and one works at Cummins.

 

[bbslider001]

Originally Posted By: A_Harman
When I was a development engineer at Cummins, I used to run hot box tests at rated power for hundreds of hours on engines with 230F coolant temperatures, which drove the oil temperatures to 280F on dino 15w40. We never worried about the durability. All that my management wanted to know was the exact date that the test would be completed.


Like Dave said, I love credible info. Was that job pretty incredible? It would be neat to see just how much goes into these designs. This is why I love this forum and other forums that people who can give real world information. I will bet that even the Edge designers put the 230* oil temp in the red zone based on their own hunches, but no real numbers. Seriously, when my Insight gauge hit 230* on the oil temp, the dial starts turning red warning the operator of temps that are too high. I could be wrong, but it does seem, after reading more, that 225-230 is not that huge of an issue.

 

[roadrunner1]

Your reaction is why several manufacturers no longer install "real" gauges in cars/trucks.
Ford is one of many whose gauges are nothing more than a glorified idiot light, because they were trying to reduce the number of consumers returning cars to dealerships because of a gauge reading high/low.
For the most part the "idiot light gauge" will suffice.

For the OP situation, he observed a temp. that more than likely was well within operating parameters, but had no idea what those parameters were. Gauges can be use for a variety of monitoring and preventitive maintainence, but one must fully understand the information presented before jumping to conclusions.

 

[A_Harman]

Originally Posted By: dnewton3

{sidebar question} A_Harman - did you work/live in Columbus? I have relatives in the area and one works at Cummins.


Yes, I lived in Columbus from August, 1990 to April, 1996. I still have some friends that work there and visit maybe once a year if I'm passing through town.