X15 questions

[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.