Don't Mix Vacuum Hose Sizes With BMW
This bulletin applies to all BMW vehicles equipped with a turbocharged engine. It’s important to note that the proper part numbers for the vacuum hose must be used when replacing the vacuum supply hoses of a turbocharging waster gate control system. Inside diameters are not all the same. For example, a vacuum hose that is used for the waste gate control is not the same inside diameter as the one used for the exhaust flap control. Interchanging these hoses will result in repeat repairs and will negatively affect customer satisfaction. Mixing the hose diameters may lead to the following complaints:
Malfunction warning or service engine soon warnings are illuminated with various boost faults stored in the DME.
Noises generated by the waste gate control system (whistling or buzzing).
Uneven acceleration under full load such as shuddering or bucking.
Always enter the VIN of the vehicle into ETK and use the proper applicable hose part numbers for the system. Using bulk hoses for all applications is prohibited by BMW.