Already a ton of info here. I had mine from 90k to 120k miles. The EGR and oil cooler were replaced under warranty at 98k. I did the necessary work to it at 105k abs it ran awesome. It ran better than my 08 Duramax with the same work done. The issues with mine were everything else, from a clogged radiator, broken/welded rims, thermostat, batteries, etc. This mostly had to do with the maintenance by the prior owner.
If you are looking for a cheap diesel and you don't mind doing research and fixing stuff, it's a great engine. Just install a coolant filter first thing along with getting the Oasis report. However being that you don't know much as you stated, I'd probably not buy one.