M57 is a solid engine. Fitted with a Webasto aux heater (as most e53 3.0d seem to be) they aren’t bothered by colder weather.

The harmonic balancer seems more of an issue in hot climates - I hear of Aussies having issues but rarely ever any Brits.

Turbo will last a long time with quality oil, changed regularly and proper use (warm up and run down).

Glow plugs need to be changed around 100,000 miles and in the M57TU LCI models, the glow plug controller will often need replacing too.

The M57TU in the LCI also came with a stainless steel exhaust manifold that can fail (split) as it gets miles on it - plenty of cast iron replacement options.

Mine has no emissions gear (beyond an EGR) so can’t comment on that. YMMV...

__________________
Wayne
2005 BMW X5 3.0d (b 02/05)
2001 BMW F650GS Dakar (b 06/01)