2012 cascadia dd15 blown head gasket

Will EGR Cooler burn Coolant, ...just curious. I had asked for a quote from a guy in winnipeg for a head gasket replacement and he said 25 hrs of labour + he will have to pressure test the head to find out if there has been a crack.

 

Wow did they feed you a line of crap!
Let's look at this from merely an observational standpoint and find out how wrong this concept it.
EGR is an abbreviation for Exhaust Gas Recirculation. What does that mean? The aftertreatment system has a portion of the componentry that Recirculates Exhaust Gas back INTO the intake tract of the engine! The quantity of EGR gas is determined by the ECM and controlled via the EGR valve.

Straight exhaust gas forced back into the engine at post combustion temperatures would be nearly hot enough to ignite the fuel injected into the cylinder in the very next power stroke alone, add to that the adibiatic heating from rapidly compressing the gas/air (this is what causes diesel ignition, there is no spark plug after all) and the peak cylinder pressures would either sieze the motor or blow the ever living $;!1 out of it!

Hence the EGR Cooler. The smokin hot ehaust gas enters the EGR Cooler, cooling the ehaust gas to a safe induction temperature. The exhaust gas flows through many small capillary tubes that have massive quantities of coolant rushing over them to effectively cool the gases. I don't know the DD numbers off the top of my head, but 78% of the water pump capacity on an ISX flows directly through the EGR cooler BEFORE even entering the block!

So now that we understand how an EGR system works, if the EGR Cooler leaks coolant into the EGR tract, where does it go? Hint: Straight INTO the combustion chamber of your engine! Yes, I mean straight raw coolant goes directly into your cylinders. If you think I'm an idiot that doesn't know what he's talking about, let me ask one simple question "How did your oil show high quantities of K (potassium) and Na (Sodium) if "...the coolant just gets into the exhaust and it gets burned up and shoots out the exhaust pipe?"

If I haven't scared you yet think about this, K & Na are extremely abrasive. How good for your engine do you think that was? Oh yeah, it's also sticky as ####, so it also bonded nicely with all that soot/carbon buildup in your oil too, yummy!

The best part is...not all of the coolant went into the engine, some of it did go into the ehaust as well, super awesome for turbos that spin at approx 110,000rpm! But that's NOT the best part, the best part is that there is no "...shoots out the exhaust pipe", remember there's these things in the way called a DOC (Diesel Oxidation Catalyst), DPFilter, and SCR loooong before the end of the stack. DOC is a big fancy title for a type of diesel fuel reactor to "oxidize" the fuel to make it ignite to burn the "particulate" (soot) out of the filter. After that, the exhaust gases go through the Selective Catalytic Reduction system, another fancy word for poisonous gas reactor to control/reduce/transform the "poisonous gas" into something safe. Big deal you say? Oh actually it is. You see Na & K also react with these "catalyst", and much much more harshly...they acid wash out the precious metals and reduce or destroy their effectiveness, but not right away, no much later on when it's not really possible to directly blame the EGR cooler WARRANTY failure, but has the appearance of just wearin out leaving you holding the bag for very expensive components...you caught the precious metals part right?

Take your own advise, educate yourself.
Closely investigate coolant leaks when they are small.
Knowing this can potentially save you thousands of dollars.

 

Yes, I would have them change the oil now.
I would then resample the oil within 3000miles, and if there is still detectable levels of Na & K, I'd change it again immediately.
A short cycle oil change to flush your system is WAAAAY cheaper than the damage the Na & K will do.
If they won't replace your DOC, DPF, & SCR cans, I'd suggest doing several short interval forced regens to try and burn the coolant out of the system as completely as possible.

When my EGR cooler took a crap, I changed the oil when the repair was done, then at 1000miles, 3000miles, and 6000miles from repair. Yes that's at 1 then 2, then 3 thousand miles on the oil. Mine went big time, I lost 5 gallons in 100miles to the shop. When I parked it in my shop, coolant was dripping out of all the EGR & exhaust joints onto the floor.

FYI, Na (sodium) is salt, K (potassium) is usually found in salt. Salt is never good for metal.
Sodium is crystal, so it has a rough surface and its hard as h377.
Potassium is a soft white metal. It's found underground and is mined as potash, which I've been at several, and it's always found in high concentrations of salt. It's ground up and looks like pink and white small rocks when it's extracted...if you've ever seen the pink road salt used in various places, thats crap grade or potash mine tailings.
Not good for metals when not properly formulated with the other additives that make it safe for use in cooling system.

 

The NOx code showed up because of the coolant in the exhaust screwing up the emission system. Now that you've fixed the issue, things may function normally, however as pointed out it may have severely shorten the life of the catalyst.

 

They changed my 1 box recently due to low Nox Conversion efficiency. $7000 for parts alone

 

Is there pressure in the system when warm? As in can you remove the fill cap without it spraying all over?