I have a young customer that has a D6R mechanical fuel that blew off a Cat Reman injector tip and caused all kinds of fun mayhem... He was told the engine was rebuilt 3500 hours ago and cylinder wear seems to match. He replaced the injectors last fall before our monsoon winter started and hasn't run it 2 hours since. He called me to stop by and see if I could isolate the faulty pencil style unit and it didn't take long. I then pulled it and found the tip gone below the carbon seal (not good). When I could see down the hole, there was obvious piston damage so we pulled the head and found it and the sleeve had taken a beating, the tip was shattered and imbeded into the crown, and the intake valve was bent way open. Two other pistons had junk in them which I assume is tip shards blown out by the bent valve and into the intake gallery and sucked back in. The turbo impeller doesn't have any visible damage. I've heard of this happening but never seen it nor the resulting damage. He was told it was likely water in his fuel. Cat will only replace the reman injector with another as they didn't install them. The current estimate is a full inframe rebuild with new aftermarket injectors through a local independent Cat guru I use.
Without knowing the full story, history, photos etc, it's impossible to make a call. What I will say however, is that in my experience lost pencil injector tips have always been a result of overheating. The damage you describe is typical.
Moisture is just about the only thing that will blow off a tip.. it cant be compressed enough to go thru the tiny holes in the tip so it blows it off..
Yeah, I cant count how many times I ran into water, even a small hint of it, hitting a hot injector tip and blowing it up.