BMW M32014 · 3.0L Petrol

Highly publicised on tuned S55 cars, crank-hub slip can throw engine timing out and destroy the valvetrain. Stock cars are less vulnerable, but mapped examples deserve extra caution.

Turbo M3s can develop small coolant leaks around expansion tanks, auxiliary coolers, or charge-cooling hardware. They are often minor at first, but repeated top-ups are not normal.