640i GT - Smoke out back

[rkmartin]

Could use some help. I had my 640 towed to the local indy shop last week after it started pouring black smoke out of the back while stopped on a local highway. After several days the shop said they cannot find any issues, car is not smoking anymore. Running perfect. The car was throwing two codes from the computer. One is 138210, and one was not thrown this time but was thrown a month back at last oil change 190F08.

The 190F08 is about a Fuel Vent System Malfunction.

Anyone face similar or have any ideas about what to do next? Feel like I'm driving a ticking timebomb now. Considering bringing to the dealer but worried with 80k miles I may be looking at some huge expense....

[Gilgorm]

I believe I had something similar to this code (138210) while under warranty. My entire lower radiator air vane system was replaced. I don't know the code but the CEL came on.
It refers to the opening/closing of the vanes in the grill. They typically open and close in the summer and often remain closed (mostly) in the winter. I doubt they would have anything to do with your problem. They only affect the cooling system. If they fail I believe they default to the open position so no harm can be done.

The second code, as you've noted, refers to the fuel vent. Had you just filled up the car?
If filled right to the top, gas can partially block the vent which normally funnels gas VAPORS back to the fuel tank from the engine. By overfilling the gas tank, the piping can get blocked until some of the LIQUID gas is used up. When refueling and my car stops the pump the first time, I never try to squeeze another ounce into it for this exact reason.
I am surprised it was blowing black smoke unless some carbon in the engine was burning off after a good highway run at higher speeds.
I'm no way a mechanic and my thoughts may be totally wrong.
Hopefully, others more knowledgeable will chime in.
Good luck and keep us posted.
Meanwhile, no smoke is a good thing. Enjoy your car.