MTU 16v2000 diesel longevity and overal comments

A little more info may be needed. I would think that your asking about 16v2000 TE90
motors in lieu to the M- 90, to 94 series.
I have found that MTU has no more issues with problems any more than other manufacturers and if there is a problem than service bulletins are issued with factory
Upgrades to rectify .
Any engine is only as good as the maintenance that it has received in the past and MTU has a "W" schedule of programed maintenance so let's say that your motors are close to 2,000 hrs on the meters. That would now require a W-2 maintenance program be carried out. Cost for a W-2 for these motors is around $ 85,000 dollars.
Are parts for MTU's more expensive than say Caterpillar? Absolutely , besides the manufacturers difference , your dealing with the exchange rates of Euro vs Dollar . That being said MTU parts aren't any more expensive than MAN or Wartsilla it's just the major difference of domestic vs foreign made

I've run a number of boats with 1500hp 12v2000's and the only problem I can recall is one boat that had coolant leaking into exhaust manifolds through the O-rings. They had to be replaced at around 4 years/1200 hours. If I recall correctly there is no MTU service bulletin for this but I've heard it's not uncommon on the 2000 series.

Otherwise I can't say a bad thing about them and I agree with captholli's comments.

The starters are Manufactured by Bosch (above average) the sea water pumps are Gear driven Gilkes and have bronze manganese impellers that will chew nails, the fresh water pumps are MTU Plant 1 Friedrichshaven manufactured and are prone to seal failure after a few thousand hours but they're on the every 1,000 hrs MTU check list when adjusting valve lash and The W schedule for a pressure / Bar discharge reading and a casing pressure test.

Wow, that's quite a bit and certainly above average. Did the mains have PTO's on them? I've run across a Moonen that went through starters for three years until we finally figured that the Port engine was starting under a minimal hydraulic load but enough of a load to take the starter out via the MTU Blue Vision start timer relay that cranks the engine uninterrupted for 4 seconds or until the oil pressure opens the circuit to interrupt the start sequence. never really had that much trouble with Bosch equipment be it their alternators or starter motors and if there were problems it was always something like low voltage or a bad crimp on a terminal in the D.C. Circuit

If the starter motor continued to run than it had to have continuous voltage to energize which would point to a faulty starter solenoid sticking closed on voltage. funny what a hammer will do to seat dirty or worn brushes on a commutator and as silly as it sounds , yes please, hand me the Technicians hammer, trust me the motor or starter WILL comply! Been there and not proud to say in a pinch, done that...

New builds have to conform with IMO tier III. a repower would be grandfathered into
Tier II and not have to comply. Still, the German iron in Bobtail arraignment sans
Gear box isn't for the weak of heart or check book. When you have a price like NEO was quoted that's a motor sitting in it's cribbage on the dock with out any ancillary sea water plumbing or electrics in the mix as far as a new build would be concerned. I priced two 16 v 2000 m-91 2,000 HP series last week and they were $400,000 each Bobtail in the shipping crates.

No gear box. Motor sitting in it's shipping crate on the shop floor.