[sinkheadhxc]

I was getting codes: P0012, P0015, P052b, as well as rough idling and some surges at stops (usually a 200-500rpm surge). I decided to just dig in and cleaned and swapped the solenoids...nothing. So I then ordered the "OEM" camshaft position sensors that Siemens offers, hearing generally good things. Unfortunately, they did not fit.

I attempted combinations of sensors and o-rings as well: new sensor w/ old o-ring, old sensor with new o-ring, etc. No matter what the combination, the old sensor would slip in perfectly every time, and the new ones weren't having it.

Fortunately, a new oil change was enough to erase the codes. Dealership most likely used the wrong, or shitty, oil. Mobil 1 European Blend 0w-40 and a MANN is what I put in... codes gone instantly, and its a completely different car than it has been the past 6500 miles: more power, smoother idle at 600-700rpm opposed to 500-600rpmm prior, less surging (but still does occasionally), smoother shift (AT), smoother acceleration....everything, basically.

I'll be returning the sensors to FCP, but I cannot believe they wouldn't fit. Even using calipers, they matched the measurements of the original sensors exactly (from what I could tell). Guess I'll just go with BMW sensors when the time to replace them truly comes and see what happens.

Just wanted to throw this out there in case anyone is experiencing similar symptoms and/or codes and gets their oil changed at a shop or dealership putting a not recommended 5w-30 in their N52 (which I assume is what was used in mine). As well as to see if anyone else has experienced this problem with the Siemens cam sensors, being that it was a total pain tinkering with those.