Upgrading your BMW M52 engine with an M50 intake manifold is a popular modification, known to enhance performance. However, this conversion can sometimes introduce complexities, particularly with wiring and vacuum line connections. One common area of concern revolves around ensuring all sensors are correctly connected and functioning, which is crucial for optimal engine performance and avoiding OBDII related issues that could, in some extreme scenarios of misconfiguration, indirectly relate to intake performance concerns. Let’s address some of the typical questions that arise during this swap.
The user in the original post encountered a few points of confusion, starting with an extra 2-pin female connector after the conversion. This is not uncommon and often requires careful tracing of the wiring harness to identify its original purpose and whether it’s still needed after the M50 intake installation. It’s important to remember that the M50 and M52 intake systems have slightly different sensor configurations.
Another point raised was the wiring for the crank sensor. The user correctly noted that while the connector they found had only two wires, the crank sensor typically uses three. This discrepancy needs investigation. It’s possible the previous owner made adjustments to the wiring that deviate from the standard setup. Incorrect crank sensor wiring can lead to significant engine performance problems and trigger OBDII fault codes.
Furthermore, the post mentions two air temperature sensors. The M52 engine is designed with an intake air temperature (IAT) sensor, but the M50 intake manifold might have provisions for a different or additional sensor. It’s crucial to understand if both sensors are necessary, how they should be wired, and where each should be located for accurate readings. An improperly installed or malfunctioning IAT sensor can negatively impact fuel mixture calculations and engine efficiency, potentially leading to issues detectable by OBDII systems.
The extra air temperature sensor spotted in the intake elbow indicates a modification from the original M52 setup. It’s vital to determine if this sensor is correctly integrated into the engine management system and if it’s providing accurate temperature readings. Using multiple or incorrectly placed temperature sensors can confuse the ECU and lead to poor engine performance.
Finally, the disconnected hose on the purge valve is a significant concern. The purge valve is part of the evaporative emission control system (EVAP), and a disconnected hose can lead to vacuum leaks and incorrect fuel vapor management. This can not only cause engine performance issues but also trigger OBDII codes related to EVAP system malfunctions. Ensuring all vacuum lines are correctly routed and connected is essential after an intake manifold conversion to maintain proper engine operation and emissions control.
In conclusion, while the M50 intake conversion can be a beneficial upgrade, it requires meticulous attention to detail, especially regarding wiring and vacuum line connections. If you are facing similar issues, it’s recommended to consult detailed wiring diagrams for both M50 and M52 engines and potentially seek guidance from experienced BMW technicians or forums specializing in engine conversions. Using professional diagnostic tools, like those from Autel, can also be invaluable in identifying and resolving any sensor or vacuum-related issues arising from such modifications, ensuring your engine runs smoothly and efficiently without triggering unnecessary OBDII warnings related to potential intake inefficiencies.
