Years ago there was a manufacturing defect with the coolant block off from the TuneMyEuro near where the coolant would feed the bottom of the EGR at the engine block. Should be just to the driver's side of the coolant thermostat. Might need a new cap/block off piece. The updated one that TuneMyEuro made was 110% overbuilt out of aluminum.
https://www.tunemyeuro.com/billet-co...p-m57-n47-n57/