I keep coming across videos and posts from people with blown engines due to pitted liners?Is that an issue with these engines? What could the cause be?
One guy had 3blown engines , I think he said. is it the coolant? I drained mine, and ran with dish detergent and flushed it a million times. First flush, I thought I had accidentally opened the engine oil pan drain plug.
the end was light brown... like a light tea sorta look.
I got the old style green coolant and mixed with filtered water.
I went through the same hyperventilation about this stuff when I bought my truck.
It's true, you don't know if the military bothered testing the coolant and keeping up with the diesel coolant additive that is supposed to prevent cavitation. Might be a ticking time bomb, might not. Probably not.
The military at least (probably) used the proper, green coolant and not the ELC (Extended Life Coolant).
While the truck is in your care, check the coolant with test strips periodically. Add DCA if test strips indicate. You'll achieve a more uniform mix if you just buy coolant "pre-charged" with diesel coolant additive. Saves you from mixing it in manually.
I also had sludge drain out of my radiator and nearly panicked, thinking of blown head gaskets and other apocalyptic visions. It turns out that the sludge is iron from the block, suspended in the coolant.
You did the right thing. Flush it with detergent, add a filter if you like.
As Simp says, don't lug the engine. My internet reading seems to indicate that these engines have a rather narrow power band. They redline at 2100-2200 but the shift point is around 1850 so you're going to be shifting frequently to keep the RPMs within that band.
Fun stuff!