When diving into auto repairs, especially for brands like BMW, understanding Original Equipment Manufacturers (OEMs) is crucial. Many believe brands like Wahler and Metzger are direct OEM suppliers for BMW, especially when you see them advertised as such across various auto parts websites. However, recent insights suggest the OEM landscape might be more nuanced, potentially pointing towards Pierburg as the actual supplier.
This raises questions, particularly when troubleshooting common issues. Take, for example, a recent experience with a valve body. Despite a thorough cleaning and inspection of a valve with over 200,000 km, including checking for proper seating and lubricating moving parts, an error light reappeared. Further investigation revealed a potential issue with the valve stem having a slight tolerance, allowing minimal rotation. While this tolerance doesn’t affect valve closure due to its round design, it can cause misalignment of the roller bearing on the actuator side when fully open. This misalignment, even with lubrication, can lead to momentary sticking. Diagnostic systems like ISTA+ suggest that even a brief deviation between commanded and read values (over 50 milliseconds) can trigger the error light.
Adding to the OEM confusion, personal observations from a fellow forum user revealed their F31 model equipped with a Wahler component, though its factory origin remains uncertain. This highlights the possibility of multiple OEM suppliers for BMW over time. The current OEM choice for BMW, especially in light of recalls, remains an open question, leaving many wondering about the true source of their car parts. The initial assumption of Metzger and Wahler as primary OEMs might need re-evaluation as the automotive parts supply chain reveals its complexities.