X15 possibly dropped liner? input please

[Rawze]

The appropriate next step is to drop the oil pan and pressurize coolant system to 20psi, let is sit over night if necessary. - Check to see where the coolant is coming from / going to. Verify what the problem is correctly BEFORE you pull the head or other expensive components off it. Otherwise, you may never know what the issue is and could be wasting your time and money.

* Could be the egr cooler, but sounds like you ruled that one out.

* Could also be the Doser injector behind the turbo, the turbo itself, air compressor, or some other circuit too.

* Have you also pulled the valve cover and checked for moisture buildup on the underside of it, or looked in the crank case filter element?. Sometimes an oil analysis will not reveal clearly that you have coolant in the oil. They are not always reliable for this.


-- More info about the truck and its history would be helpful too. Like others have asked ....

* Is the engine de-mandated? -- and if so, By who was it done?

* What is the rear ratio of the truck?

* Does it get driven regularly more than 1/2-way down on the accelerator (or harder) much below 1500 rpm's when climbing mountains, etc.?


-- These are all things that will contribute to a shortened engine life, and especially a dropped liner/blown head gasket.


NOTE: It has also been a prediction on here that the 500+hp X15 series engines are generally not going to last as long as the CM2350's. No one wants to see this, but it is a predicion based on past experiences with the ISX as a whole on here. , seeing engine after engine (CM2350 X101's) fail at 600-700k miles due to their 18:9 compression ratio, and the X15 has an even higher compression ratio (19:1/19:3), dictating that they would not make it much past 500k miles if they are set much above 1750 torque in the bottom end of the working range (below 1500 rpm). - (speculation) That red engine company seems hell bent on abusing these newer engines in these last few years by putting a lot of heavy torque in the bottom of the working range + tall gears in the truck (truck makers are guilty too), severely shortening the engine life to please the mega-fleets needs at the expense of the engine's million mile longevity.
Here is one of those previous discussions on a search: http://rawze.com/forums/showthread.php?t...2#pid37802