The E90 is a diesel, I assume? I mean, the valve is full open 99% of the time. It shuts only during engine shutdown briefly, in a runaway situation, and otherwise trims air input during regeneration post-fueling. I guess a spring that holds it open is okay. The one I replaced in my X5 seemed direct driven, no springiness at all and I hear it reposition open after the engine has stopped, a few seconds later. Maybe it was a later part change. My X5 is a late 2011 LCI model.

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8/2011 X5 xDrive35d Sport, Black Sapphire Metallic, Black Nevada Leather, Fine Burr Walnut Trim
2/2001 M5, Jet Black, Exclusive Complete Black Walk Nappa Point Heritage Leather, Black Cubic Trim