[Alfa75]

2008 128i, completely stock and well maintained. Started it up for the year and took it out for a drive to get gas. On the way back, the engine started stumbling uncontrollably after accelerating from a high load/low rpm (pre-downshift on autobox) and a giant cloud of smoke came out the tail pipe and CEL was on. I pulled over, shut off and restarted. It ran perfectly the whole drive home, until I put in in park and it started stumbling again. I connected my scanner and ran some diagnostics (see attached) and found that the intake cam was completely out of alignment.
I was planning on changing the valve cover gasket anyways so, while I was in there I confirmed that the intake cam was truly out of timing. I set everything to TDC, reset the cam positions, replaced the vanos solenoids with new, removed cleaned and reinstalled the vanos check-valves/filters on the side of the block, and threw in a new set of plugs while I was in there. I ran every self test that my scanner could including the DCT all of which passed. For good measure I've also replaced the intake cam sensor. It started up and ran perfectly. I then ran two consecutive oil flushes with fresh filters and finally I changed the oil with a quality synthetic and mann filter. I did all of this with intent of cleaning out any sediment from the cam phasers.
Now it runs perfectly 90% of the time but intermittently it exhibits the same symptoms under a load but the CEL clears itself after a restart and the codes don't store.