N55

In 2006, BMW introduced a new mass-produced turbocharged engine for the first time in twenty years—the N54. Three years later, they released the N55 as a successor to the N54, which offered fuel efficiency and reliability improvements over its predecessor. While the two engines have their differences, at their core they’re both three-liter, turbocharged straight-six engines, both put out over 300 horsepower, and both were used for as the powerplant for numerous BMW models. But they have something else in common—a weak point.

Hop onto any BMW forum and search for either engine with the words “charge pipe”. It won’t be long before you find post after post about the charge pipes on these engines cracking and failing, even on stock tunes. The OEM charge pipes used on the N54 and N55 engines are plastic, which becomes brittle and weak after time and repeated heat cycles. Once the charge pipe cracks, the engine begins drawing