Only enough to clean it off. I agree with you. I looked down there with a bore scope first and it was pretty crud filled. Short of replacing the part, this was my best option.

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2001 x5 3.0 (sold with broken motor), 1990 e30 M3, 1991 318is, 2002 325i, 2008 335i Dinan stage 3 6 speed,