After removing the valve cover on my 2011 328xi, I discovered that 3 of 4 bolts that go through the intake cam sprocket were sheared off completely. The 4th one had it's head missing, and was backed out about halfway which was the only thing keeping the Camshaft Adjuster in place. There was a BMW recall regarding this exact issue, but from what I have been able to find, the recall only applies to N55 engines (turbo). The dealer ran my VIN and told the same story. So I will be replacing the sprocket and camshaft adjuster on my own. Looking for words of wisdom in replacing this such that I don't have to set the timing when I install the new sprocket. I would also like to replace the bolts on the exhaust side, because they're probably compromised, even through they haven't failed yet.