Isx 15 Oil overheating

[Ozzie18]

I have a 2014 kenworth T660 with 580xxx miles Isx 15 Cm2350 which I've been having issues with high oil temperatures. I understand these engines are supposed to run hotter temperatures up to 245 may within normal range. My truck has the same symptoms that I've read about on this site. If i don't turn on the fan on long pulls the temperature can get up to 265, 270, maybe even 275. Engine service advised light turns on at about 265-270 F. It only does this when loaded and even on a flat road with high winds it has heated up on me. Ive flushed out the coolant, swapped the water temperature sensor, coolant thermostat, they replaced the oil cooler, and just last week they replaced the Oil thermostat and on my very first load going not even 15 miles it got up to 248-250 real quick. Im running out of denver so it still not very hot out this time of year. Thanks for your help in advance!!

[Bengy88]

Has it been de mandated? Not saying everything leads to a bad tune but we have seen high oil temps from this.

[Rawze]

The oil temps should typically run about 30-F or so (38-F max) above the coolant temps when pushing high operating loads.

This means that someone seeing 245-F + oil temps is actually too high too, and is a sign that the engine is going to live a very short lifespan, so it sounds to me like you have a serious issue if it is even higher than that.

So someone telling you that 245-F is normal is someone who is abusing their equipment in one way or another and likely does not know any better.

Also, the #1 cause of excess or higher than normal oil temps is almost always garbage-can delete files being used.

- If that truck is deleted, then copy the program from the ecm and e-mail it to me for a proper review of what someone has done inside the programming as a start, and then go from there.

[Ozzie18]

(04-24-2023 )Bengy88 Wrote:  Has it been de mandated? Not saying everything leads to a bad tune but we have seen high oil temps from this.

Sorry forgot to mention this but no it’s not deleted

[Ozzie18]

(04-25-2023 )Rawze Wrote:  The oil temps should typically run about 30-F or so (38-F max) above the coolant temps when pushing high operating loads.

This means that someone seeing 245-F + oil temps is actually too high too, and is a sign that the engine is going to live a very short lifespan, so it sounds to me like you have a serious issue if it is even higher than that.

So someone telling you that 245-F is normal is someone who is abusing their equipment in one way or another and likely does not know any better.

Also, the #1 cause of excess or higher than normal oil temps is almost always garbage-can delete files being used.

- If that truck is deleted, then copy the program from the ecm and e-mail it to me for a proper review of what someone has done inside the programming as a start, and then go from there.

I forgot to mention that has not been deleted yet. I got that information regarding the oil temp from the kenworth booklet that came with the truck as well as online.

[Rawze]

(04-25-2023 )Ozzie18 Wrote:  ...
I forgot to mention that has not been deleted yet. I got that information regarding the oil temp from the kenworth booklet that came with the truck as well as online.

Does not matter what the book says.. 245 is the upper extreme and should rarely be seen if at all. Believe me, I see a lot of trucks and know what temps they run.

You can choose not to believe me but you do so at your own loss.

If it is not de-mandated and you are seeing excess oil temps like that then something somewhere is wrong!>.

Might be carbon packed, causing too much internal friction to the cylinder walls.. might be a slopped cam, might be a lot of things... but something somewhere is very wrong wit the temps you describe.. that or someone is abusing it, perhaps at low rpm and high torque, and the coolant is getting real hot too. -= maybe plugged up radiator with dirt etc.. and coolant temps are running high all the time,etc..

That or something internal causing to much friction, overheating the oil?.
Maybe bad oil thermostat?. .. who knows


-= I.E.> something.

[Ozzie18]

(04-25-2023 )Rawze Wrote:  

(04-25-2023 )Ozzie18 Wrote:  ...
I forgot to mention that has not been deleted yet. I got that information regarding the oil temp from the kenworth booklet that came with the truck as well as online.

Does not matter what the book says.. 245 is the upper extreme and should rarely be seen if at all. Believe me, I see a lot of trucks and know what temps they run.

You can choose not to believe me but you do so at your own loss.

If it is not de-mandated and you are seeing excess oil temps like that then something somewhere is wrong!>.

Might be carbon packed, causing too much internal friction to the cylinder walls.. might be a slopped cam, might be a lot of things... but something somewhere is very wrong wit the temps you describe.. that or someone is abusing it, perhaps at low rpm and high torque, and the coolant is getting real hot too. -= maybe plugged up radiator with dirt etc.. and coolant temps are running high all the time,etc..

That or something internal causing to much friction, overheating the oil?.
Maybe bad oil thermostat?. .. who knows


-= I.E.> something.

Coolant stays around 200-210 when oil temperature goes up past 240 and fan kicks in at 210. I don’t recall ever seeing it get past 211-212. I replaced the radiator not too long ago as well for a different reason but I was already having these high oil temps before I replaced it. I just replaced the oil thermostat as well. Do you mind explaining a little more on the low RPM high Torque thing please??

[Bengy88]

(04-26-2023 )Ozzie18 Wrote:  Coolant stays around 200-210 when oil temperature goes up past 240 and fan kicks in at 210. I don’t recall ever seeing it get past 211-212. I replaced the radiator not too long ago as well for a different reason but I was already having these high oil temps before I replaced it. I just replaced the oil thermostat as well. Do you mind explaining a little more on the low RPM high Torque thing please??

Do you lug the truck? Or do you keep the rpm’s up around 15-1600 range? If the engine is being lugged then it’s just working harder to do its job. Low rpm’s aren’t necessarily a good thing, every engine has a “sweet spot” and an isx happens to be 15-1600. Now don’t take that and think you are supposed to run wide ass open everywhere you go but running an engine at too low of rpm’s is just as bad, if not worse than raw hiding it.

Also how heavy are your loads. I’ve seen trucks set with the horsepower entirely too low and complete wrong gears/ and or transmission for heavy haul but still pulling 100-140k loads and almost always the oil temps rise to the 245+ range. If your temps continue being ran like this you will eventually spin a bearing or break a crankshaft. It may not be tomorrow and it may not be 2 years from now but it will happen.

Don’t think I’m telling you how to drive your truck (I don’t know how you drive) but if you are driving it in any of these ways then you are driving wrong lol. Im just giving insight on what may be happening.

This is just the way my brain is thinking tonight. If I’m wrong someone call me out on it. I could use a good yelling after today lol.

[Ozzie18]

I am all ears right now so any and every piece of advice will be welcome especially coming from people who know more than me. I’ve been driving for about 5 years now so I’ve got a whole lot of learning to do. So I haul cars on an 8 car hauler so my total weight is rarely 80k if ever. Im usually more on the 65-75k and I only run locally out of Denver. No mountains and no long steep pulls. I was running loaded once on a flat road cruising at about 70mph with winds at about 30mph or so and the oil got up to the point where the light came on. As far as the rpms I’ve barely paid attention to those. If I’ve been driving with low RPMs it can’t be lower than 1400-14500 and that may be only sometimes. but I will definitely pay more attention to that.