Like some others said it could be a spares issue or suitability with local conditions.
Bangladesh weather (high humidity) and the Army's engine maintenance regimes could be factors.
Boxer engines have higher energy density and require more careful upkeep - this is a typical problem with Porsches and Subarus, which use Boxer type engines as well. It all started with the VW Bug which used a flat four Boxer engine, but that was VERY reliable (and air-cooled).
The 6TD-2 Ukrainian engine for the Bangladeshi MBT-2000 is a Turbo-Diesel with extremely high compression to produce the 1200 HP power output. Which makes careful and more frequent maintenance a must. Moreover the design is a complicated reverse Boxer with six cylinders and twelve pistons (two pistons per cylinder working in opposed fashion).
That is the final chapter of this story. Something made in China itself, which can be reasonably maintained and supported with easily obtainable Chinese spares.
