Valvetronic valve-lift system
Varies how far the intake valves open to control airflow.
In the cylinder-head intake valve gear on equipped petrol engines.
An eccentric mechanism changes the motion delivered to intake valves; it works alongside cam-timing control.
Opening a door a little or a lot to regulate a crowd.
Starting difficulty, reduced-power warnings or adaptation faults can have electrical or mechanical causes.
Usually condition-based rather than a routine replacement. Lubrication, overheating and the exact engine affect wear.
Internal-engine work is usually labor-intensive. Diagnosis and the engine code determine the repair scope.
Valvetronic adjusts valve lift, while VANOS adjusts timing; equipped BMW engines can use both.
Equipped BMW petrol engines, including the B38 family. It is not present on every BMW petrol engine.