The BMW VANOS system (variable Nockenwellensteuerung - variable camshaft timing) was introduced in the early 1990s as a way of altering timing based on RPM and engine load to improve torque delivery, fuel economy, and engine smoothness. The first systems were single-VANOS and operated the intake cam only. Beginning in 1999, double-VANOS was introduced that did both intake and exhaust banks (on both inline-6 and V8 engines).
By 150,000 miles the original VANOS actuator solenoids, seals, and o-rings are usually due for a complete replacement. Some individual pieces may have been replaced already. Signs of a dying unit are loud marble-like rattles from the front of the engine, loss of power and mid-range torque, poor fuel economy, and fault codes for misfires and VANOS-related sensors. VANOS sensors, solenoids, and some other parts are available separately. VANOS units can be rebuilt by sourcing the seals and o-rings on their own but that process still requires expert mechanical knowledge and special tools. We prefer to offer complete, rebuilt VANOS units to make the replacement as seamless and trouble-free as possible for you.
Note: all VANOS systems require special tools for correct repair and replacement. These tools are BMW specific. If you do not possess these tools we strongly advise you to bring the parts to a qualified and experienced BMW technician who does.
