BMW 328i xDrive noisy cabin ventilation fan issue after motor replacement on BMW 328i xDrive

Some BMW 328i xDrive owners report experiencing a noisy cabin ventilation fan issue following a motor replacement. This noise may be caused by a small leaf lodged inside the cylinder-type fan, which can occur due to abrupt pressure changes in the filter chamber. Additionally, some owners notice that the noise resembles the heater or AC fan operating at a low setting, even when the fan is off, potentially indicating issues with the radiator fan or normal cabin noise. Others have reported that vent fans may abruptly stop, despite the digital readout showing they are on, a problem often linked to the vehicle’s age rather than mileage, typically around 5-6 years. Furthermore, increasing the fan speed can lead to a situation where the fan pushes hard but only a trickle of air comes from the vents, accompanied by a whistling sound, which may suggest air is escaping through a gap. It is recommended that owners carefully inspect the fan for obstructions, check the filter chamber for debris, and ensure the motor replacement was performed correctly to resolve these noisy ventilation issues.