BMW Valvetronic Eccentric Shaft Sensor - VDO 11377524879

Automakers have taken great strides over the years to pull out every last bit of power and economy from normally aspirated engines. The advent of highly-capable engine computers has made many advancements possible, including redesigns of older tech. Variable Valve Lift isn’t a new idea and has been adopted by nearly every major manufacturer, but designs vary between manufacturers. BMW’s Valvetronic is their version, utilizing a unique design that is far more advanced than other manufacturers for superior performance and economy. When it’s working, that is.

BMW N51/N52 Valvetronic Variable Valve Lift System

The BMW Valvetronic system is very different from the systems found on Hondas and Porsches. Instead of a split-lobed intake camshaft with a two-stage tappet that delivers high and low profiles, the Valvetronic system is infinitely adjustable within a wide range. Along with the standard finger follower that pushes down on the valve to open it, the N51/N52 has a third lobed shaft called the eccentric shaft that sits above the intake valve. An arm that follows the intake camshaft is connected to the eccentric shaft and actuates the intake valve. The eccentric shaft’s position determines the arm’s position and, consequently, the intake valve’s lift.

The engine computer or DME controls the eccentric shaft’s position, determining how much the valve opens. It controls the shaft through a sensor and an electric motor that meshes with a gear positioned in the middle of the shaft. The DME needs to know where the eccentric shaft is at all times for the system to operate effectively, and there lies the potential issue. 

BMW N51/N52 Valvetronic Eccentric Shaft Sensor Faults

The two main failure-prone components of the Valvetronic variable valve lift system are the Valvetronic motor and the shaft’s position sensor. Motor failure can occur from damaged motor internals, low system voltages, or a binding/sticking eccentric shaft. The sensor has fewer moving parts but is generally the one to fail first, as its position inside the valve cover leaves it susceptible to oil damage. Once oil enters the sensor, it destroys the electronics and causes faulty readings. In both cases, faults will occur gradually as damage slowly worsens. 

BMW N52 Valvetronic Eccentric Shaft Sensor Failure Symptoms

• Struggling to start in cold weather

• Excessive fuel consumption

• Loss of power

• Rough running/surging idle

• Illuminated/flashing CEL

• Oil inside the sensor’s plug

BMW N52 Valvetronic Eccentric Shaft Sensor Failure Codes

• P1014 

• P1017 

• P1023 

• P1030 

• P10DF 

• P10E0 

• P10E1 

• P10E7 

• P10E8

• 2A37

• 2A47

• 2A45

• 2A43

• 2A77

• 2A3F

• 134E08

Once you have some of these symptoms and the associated codes, you’re likely looking at a Valvetronic eccentric shaft position sensor failure. It’s the most common cause and relatively easy to access in most N52 engine bays. The sensor sits at the front of the engine under the valve cover, so that’s all you have to remove for access. Three easily accessed 10mm bolts hold the sensor into the head. 

BMW N51/N52 Valvetronic Eccentric Shaft Position Sensor Replacement

This VDO 11377524879 sensor is a direct OE replacement of the original sensor. Along with the new sensor, you’ll need a few other items for replacement, including a new sensor gasket, a valve cover gasket set, and an eccentric shaft actuator seal.