2015-2020 BMW M4 Problems: 5 Known Issues

The S55 engine has tight rod bearing clearances that can lead to premature bearing wear, especially with track use or aggressive driving. While not as severe as the S65 V10 rod bearing issue, the S55 still experiences accelerated wear. Symptoms typically appear after 60,000-80,000 miles or after sustained track use. Oil analysis showing elevated copper/lead levels indicates bearing wear. The twin-turbo S55 generates high cylinder pressures that stress the bearings. This issue is shared with M3, M2 Competition, and all S55-powered cars.

The S55 engine in the F82/F83 M4 (2015-2020), which is also used in the F80 M3 and M2 Competition, has a factory crank hub that is not keyed to the crankshaft. The timing parts are held in alignment only by friction washers and the clamping force of the central crank bolt. Under high load, hard launches or sudden throttle changes, those friction surfaces can slip. When that happens the engine falls out of timing, and if it moves far enough the pistons can hit the valves, which can ruin the engine. Tuned and tracked cars are discussed most, but specialist shops also report hub failures on cars at stock power in normal driving. BMW has not issued a recall or service bulletin for it, so the problem is known mainly through owner reports and aftermarket specialists.

The factory plastic charge pipe on the F82 M4 S55 engine is known to crack or blow off the intercooler under high boost, especially in hot weather or with any tune increasing boost pressure. The plastic material becomes brittle with heat cycling and eventually fails at the crimp connections.

The F82/F83 M4 has marginal cooling capacity for sustained track use. The S55 twin-turbo engine generates significant heat, and the stock cooling system struggles during extended track sessions. Oil temperatures commonly exceed 280°F, coolant temps spike, and the car experiences heat soak and power loss. The intercoolers also heat soak, reducing boost efficiency and power. BMW's factory cooling is adequate for street use but insufficient for track duty. This is a well-known issue among M4 track enthusiasts.

The Getrag DCT (dual-clutch transmission) in the M4 experiences clutch pack wear from aggressive driving, repeated launch control, and track use. The DCT has two clutches (odd and even gears) that wear over time. Symptoms include shuddering during low-speed acceleration, rough shifting, and slipping under hard acceleration. Track use and launch control dramatically accelerate wear. DCT fluid degradation also contributes to poor shift quality. Clutch replacement is expensive ($5,000-8,000) and considered a wear item on high-performance use.