The S55 twin-turbo engine that powers the BMW M2C / M3 / M4 F8X has a horizontally mounted engine oil cooler positioned underneath the center cooling module. This stock engine oil have a tube and fin core which is a bit sensitive construction and therefore it can be damaged by road debris. So with this type of core installed in this position it is not very unusual to get a sudden oil leak caused by a small stone or other debris hitting the stock oil cooler and this can be fatal for the engine.
