Common failure point (among others). For a comprehensive review of M54 engine coolant system maintenance issues see:

Part 1 BMW Cooling System Overview with Common Failures for e36, e46, e34, e39 - YouTube

Part 2 BMW Cooling System Overview with Common Failures for e36, e46, e34, e39 - YouTube

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2021 X3 M40i Glacier Silver
2016 X5 xDrive 35i Mineral Silver

Gone but not forgotten
2017 X4 M40i Black Metallic
1985 325e Cosmos Blue
2006 330i Monaco Blue
2006 X5 Ti Ag
2000 528i Ti Ag
1986 535is Black (great ride)
1985 528e Polaris Silver (GTA in NYC)