Still haven't resolved my rough idle problem - E90 328xi with 87K miles. It occurs mostly with the AC and fan off - the whole car shakes, the engine looks like it's going to jump out. Sometimes I see white smoke too.
This started occurring 2 days after I went to the dealer to do a coolant flush, oil change (to non BMW LL01 oil!), and transmission oil change. After a while CEL is on. Went back right to the dealer, they said the VANOS solenoids are bad, so they replaced those (on my $ of course), but problem still exists. Then they said the oil filter cap is broken and denied they broke it 2 days ago, ok, so I pay for a new cap.
After this mess, problem still existed, though the CEL never came back. I also often hear high pitched noises, as if a plane is landing, while in the driver's seat.
INPA shows some errors in the history, like ebox fan problems, but the status is "OK" right now, so not sure if any of the problems are relevant.
I also had rather weaker AC after retrofitting CCC idrive, 6FL and BT. Now I have to explicitly choose only the vent settings to the front blowers (the middle button), otherwise the fan is blowing somewhere else that makes no difference in the cabin.
Any ideas what could be the problem? I love to work on stuff myself, but I do not have a garage so I can't do any work involving fluids. But seems like even the dealerships cannot be trusted. Indie shops nearby are a joke - e.g. they only use non BMW LL01 oil and "if you bring your oil we cannot warrant our work, don't blame us if the oil leaks"