Poorly ML 300CDI

[AHUX]

Hi All, I am looking for a bit of advice, a few weeks back we bought a 2009 ML300 CDI (190bhp engine) from and independent dealer with 65k on the clock. Unfortunately, the car conked out and it turns out that the tensioner for the timing chain has failed resulting in significant amount of damage to the engine, so much so the car needs a new engine.

Have I been unlucky here and picked a lemon, or is timing chain failure a common fault (haven't seen much on it when I search)?

Secondly the new engine they are sourcing is a remanufactured engine, from Vege - never really heard of remanufactured engines (not sure if this is the same as re-built), or Vege - anyone had any experience with these?

[mbtech01]

I've never heard of a timing chain tensioner failing on the 642 v6 diesel engine, but I've seen timing chains go slack & cause problems usually around the 100k mark on this particular engine. With the right tool the chain can be replaced without stripping too much or engine removal. I know this is no help to you but I think you may have been just unlucky in your case unless the vehicle had poor service history with irregular oil changes & possibly wrong grade of oil being used.
I wish you luck in finding a replacement engine & hope you get it sorted soon.