One BMW M3 engine with an S55 motor suffered such a severe breakdown that it virtually destroyed its own cylinder head. The story was analyzed by the authors of the popular channel I Do Cars.

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Источник изображения: Youtube channel I Do Cars

This refers to the 3.0-liter twin-turbo S55 engine, which was installed in the BMW M3 and M4 of the F80/F82 generation. This engine is considered one of the most successful modern BMW M engines: it produces 425 hp from the factory, handles tuning well, and usually does not cause serious problems with normal maintenance.

But this particular unit was brought to a catastrophic state. During disassembly, it was found that the sixth cylinder suffered severe connecting rod bearing failure. Metal shavings spread throughout the lubrication system, oil starvation began, and the camshaft literally started grinding down the cylinder head. Some elements of the valve train were fractured.

Most tellingly, the engine likely continued to operate even after a serious malfunction began. Experts note that modern BMWs usually warn of problems in advance: oil pressure drop, unusual noises, and overheating. But if these signals are ignored, even the robust S55 can be almost completely destroyed.

The topic of connecting rod bearings for BMW M is not new. Similar problems previously gained notoriety on high-revving V10 and V8 engines of the S85 and S65 families. However, the S55 case shows that even modern turbo engines remain extremely sensitive to oil quality and service intervals.

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