Owning a powerful BMW asks for a little education. This is not like an average car that you can ride without worrying about anything. Instead, a BMW asks for a lot of care and dedication. Moreover, most new owners have no clue about the common problems they might experience with BMW 320d swirl flaps. Swirl flaps have one simple purpose – aid the combustion and ensure a decent rapport of air and fuel. Unfortunately, they are often defective. Even BMW has admitted it. Therefore, they lead to a series of issues overtime. Reparations can be expensive, but ignoring them might ask for a brand new engine.