Inline-sixes tend to have problems tied to their size and length, higher camshaft flex and torsion, uneven air/fuel distribution, and timing chain problems.
2/4 problems are BMW problems, 1/4 problems are old engine design problems that are fixed in modern engines, and 1 physical problem is fixed by better materials and engine design.
2/4 problems are BMW problems, 1/4 problems are old engine design problems that are fixed in modern engines, and 1 physical problem is fixed by better materials and engine design.