
BMW has issued Service Information Bulletin SIB 64 01 25 to address an intermittent humming or foghorn-like noise in certain 2023-2024 X3, X4, 3 Series, and Z4 models. This sound is often caused by the air conditioning expansion valve.

BMW has identified an issue where certain 2021-2023 models may experience an engine jolt during light acceleration, particularly after the engine has run for an extended period while stationary in hot ambient conditions. This manufacturer communication, NHTSA ID 10236218, provides details.