X15 questions

[marek4792]

(09-16-2020 )Explosia Wrote:  

(09-16-2020 )marek4792 Wrote:  does the temperature seem to hang when the fan is on? and when the truck does cool down like leveling out does the coolant temperature drop below operating temperature like close to 160 degrees or so?

No it works like it’s supposed to, just get hot easier than my old 2350. Well so far no one seems to say somethings wrong, I guess that’s the way it’s supposed to run? The warranty runs out soon I will be visiting my favorite shop in Georgia, I wonder if that file will make a difference?

That seems to be the case with them unfortunately.. Uni tuned mine and my oil temperature doesn't go any higher than 243 degrees although my coolant temperature is higher, but doesn't go above 215 with the fan on most likely I could have a bad coolant tank or coolant thermostat on my end or too much crap in the radiator.

[Explosia]

Well I guess that answers that question.

[Papa_Buck]

I have 3 X15 2350 motors set at 600 hp, all in Kenworth W900's from 2017 - 2019's. We also pull the Baker grade in the mohave desert, and the I-17 out of phoenix, and have noticed the heat in the oil and water pulling these grades. We didn't let the oil get into the red, but there were times it got like your pic. That was when we were driving the truck like the service people at Cummins told us to.

After coming here and getting educated, I have my drivers running the motors between 15 and 2000 rpm and the oil and water temps have come down. Keeping the RPM up and shifting down has made a difference in the temps. We have the oil temp guages in the dash, and on the Pacar trucks (Kenworth and Pete) you can have the computer display a computer generated guage from the dash display (If you have that option)

I also noticed a drop in the temp again when I installed the bypass filters and added another gallon of oil to the system.

Just my experience.

[Rawze]

(09-17-2020 )Papa_Buck Wrote:  I have 3 X15 2350 motors set at 600 hp, all in Kenworth W900's from 2017 - 2019's. We also pull the Baker grade in the mohave desert, and the I-17 out of phoenix, and have noticed the heat in the oil and water pulling these grades. We didn't let the oil get into the red, but there were times it got like your pic. That was when we were driving the truck like the service people at Cummins told us to.

After coming here and getting educated, I have my drivers running the motors between 15 and 2000 rpm and the oil and water temps have come down. Keeping the RPM up and shifting down has made a difference in the temps. We have the oil temp guages in the dash, and on the Pacar trucks (Kenworth and Pete) you can have the computer display a computer generated guage from the dash display (If you have that option)

I also noticed a drop in the temp again when I installed the bypass filters and added another gallon of oil to the system.

Just my experience.

Those lower oil temps = less internal engine wear and friction.

[Explosia]

(09-17-2020 )Papa_Buck Wrote:  I have 3 X15 2350 motors set at 600 hp, all in Kenworth W900's from 2017 - 2019's. We also pull the Baker grade in the mohave desert, and the I-17 out of phoenix, and have noticed the heat in the oil and water pulling these grades. We didn't let the oil get into the red, but there were times it got like your pic. That was when we were driving the truck like the service people at Cummins told us to.

After coming here and getting educated, I have my drivers running the motors between 15 and 2000 rpm and the oil and water temps have come down. Keeping the RPM up and shifting down has made a difference in the temps. We have the oil temp guages in the dash, and on the Pacar trucks (Kenworth and Pete) you can have the computer display a computer generated guage from the dash display (If you have that option)

I also noticed a drop in the temp again when I installed the bypass filters and added another gallon of oil to the system.

Just my experience.

I have been a student of rawzes for a few years now, and have driven my trucks like he teaches. The temps that I posted are pulling grades at 20 lbs or less. I do let it pull down to 1450 or so, but I feel it isn’t detrimental to the engine as I’m using 10-20 lbs of boost. I haven’t put in a bypass because like I posted before I’m gonna visit Georgia soon. But it is reassuring that other X15’s are preforming the same and mine is not an anomaly. Still not happy with the high oil temps, like rawze says that leads to higher friction and engine wear.

[marek4792]

Done some more digging on the web and actually found a follow up to this thread. http://rawze.com/forums/showthread.php?tid=4148 that was posted on here awhile back.
orignal link to qoutes below.

Quote:"I have now visited my third shop to have my Cummins overheating problem resolved. I have previously reported that I was told by a Cummins expert and then independently confirmed by a Cummins Customer Service rep that the oil temperature thermostat in my X-15 605 hp was spec'd to be 260 degrees. I reported some self reports as I drove from Phoenix to Casa Grande, and then again from Casa Grande to Yuma and all of that were consistent with oil temps rising to 258 degrees and then gradually declining but remaining in the 235-245 range. After driving back from Yuma to Tucson, I am now at the Tucson satellite Cummins shop and today they removed my oil temperature thermostat. They also determined that the thermostat should be one that opens at 235 degrees, which is the same as the ISX-15 600 hp engine. So, they analyzed my original thermostat and ran the temp around the thermostat up to 600 degrees (!). They reported that the thermostat barely opened even at 600 degrees, and that it moved just a little as it cooled down, never fully closing."

Followed by this...

Quote:"Well, some very good news. Logged 350 miles today from Tucson to near El Paso and the Cummins ran just the way that it should run!!!

Again watched the oil temp like a hawk virtually the whole trip. Engine oil came up to temp of about 225 and then climbed to 235ish, however the general temp while driving 69 mph (75 mph zones) the engine oil temp was 225 most of the time. When climbing up and over the smaller continental divide in Arizona and New Mexico, the highest temp I saw was 239 degrees climbing hills, and when it hit 239, then it fell quickly back to 235 and lower 230s, so I am guessing that this whole thing was a problem with an oil cooler unit thermostat that suddenly failed. The good thing is that I now know a lot more about engine oil characteristics and performance in this engine, and hopefully it will be useful information for others who may experience some problems."

So if this guys issue was indeed the oil t-stat and the temps mentioned are under 100% load, we could very well be dealing with a bad batch of oil t-stats and we shouldn't even be seeing 240 degrees let alone 250 or 260 like this RV guy has..
They changed the oil t-stat design for the x15 which closely resembles the coolant t-stat as well.