[Sethsquatch]

OK so! Finally got my Pinzgauer from the shop, engine was running like a champ, the mechanic was able to talk to a technician in the UK who walked him through adjusting the fuel pump, and it was running good.
I picked it up and noticed quite a bit of black smoke as I was driving. (later the mechanic told me it barely was smoking when he had it adjusted.)
After driving 20-25 mins, there was a *clunk* sound from the engine, and the clattering actually got much quieter from the engine. I figured the noise was typical diesel, I hadn't driven it in 5 months, so didn't remember how loud it was. So clunk noise, black smoke immediately diminished, but now putting out BLUE
smoke and tons, 😬 I was only 2 mins from my house so I got it home, it still ran quite well, but during the cool down idle, it was putting out blue smoke like a chimney, a lot.
I am open to any speculation or suggestions on what could be wrong. This is obviously not my area of expertise, the mechanic is going to take it back after the first of the year, but I'd love to give him some ammunition to what could be the issue.
Thank you advance!
Seth