2021 BMW 840i xDrive Crankshaft Position Sensor Replacement Cost

Using a professional-grade scanner, a mechanic can read where the sensors think the crankshaft and camshaft are, and compare this to their actual position. If the reading from either sensor is incorrect, the sensor will be tested and replaced if necessary.

To replace the crankshaft position sensor, you have to disconnect any electrical connectors and then unscrew the sensor. Sealant may be applied before inserting the new sensor into the engine. On some vehicles, the crankshaft position sensor is located inside the engine block, and significant deconstruction is required to get to it. In these cases, we recommend trusting a professional technician with the repair.

Make sure to use high-quality, OEM sensors. Lesser products will likely cause a repeated repair. When checking this sensor, the vehicle's timing belt should be inspected as well. If the timing belt or timing chain has failed, it should be replaced and the engine should be further inspected.

Replacing this sensor is easy enough — but what's often tricky is getting the correct diagnosis. Unless you have the proper scanning tools and knowledge, it's likely best to let a professional technician handle this diagnosis and repair.