I posted this over on bimmerforums, but I figured that I'd post it here as well as it gets more traffic. FYI:
I wanted to post up my information as a counterpoint to lots of what I found when searching here, Bimmerfest, and e90post. It's often said that people never come to the forums to post good news, and that as a result they cause hysteria. I'm here to do the opposite. Hopefully this indicates that the cam bearing ledge issue isn't as widespread as it seems.
My car threw a check engine/reduced power light while driving down the highway. I limped it home and had my friend who owns a local BMW shop meet me to check it out. He used his scan tool and we pulled 2 codes, 3100 and 2a87.
Per SIB 11 02 08 for the n54 motor, BMW advised to check for abnormal wear to the cam bearing ledge which would cause reduced oil pressure, a jammed VANOS, and these codes. My friend advised me to call BMW Roadside Assistance to pick up the car and bring it to my dealership.
At this point I was pretty upset, because the info that he gave me combined with everything I read on the forums led me to believe that the car had serious engine problems. Because the forums make it sound like this problem is very widespread, I was afraid that even if they replaced the parts it would happen again eventually.
The car was ready yesterday, and it turns out they removed both the camshafts and the ledges and found NO ABNORMAL WEAR. They replaced both VANOS solenoids because they may have been gummed up with oil particles (Defect code 1113937600). After this the issue went away and hasn't returned. The car has almost 45k miles on it and I drive it spiritedly on a daily basis. Here's the writeup:
The car has another 4k miles on it since this service and hasn't shown any signs of returning - in fact, it seems to pull a bit harder throughout the RPM range according to the old butt dyno.