M50TU | M52 | S50 | S52 Single VANOS Rebuild Kits

The Single VANOS system found on BMW’s M50TU, M52, S50 (US), and S52 (US) engines is an early form of variable valve timing that adjusts the position of the intake camshaft only, while the exhaust camshaft remains fixed. Controlled by the engine’s DME, an oil-pressure-operated piston and helical gear mechanism switches the intake camshaft between advanced and retarded positions based on engine speed, load, and temperature. This allows BMW to optimize valve timing for different operating conditions, improving low- and mid-range torque, throttle response, idle quality, fuel efficiency, and emissions without sacrificing high-RPM performance. The M50TU introduced Single VANOS to BMW’s mainstream inline-six engines, and the basic design continued with the M52 before BMW transitioned to Double VANOS on the M52TU.