BP ultimate, or any other fuels or fuel cleaners do nothing, because in direct injection engines the fuel does not touch the valves, since is getting sprayed after the valves directly into the cylinder.
Here is a video from a 335i engine before and after cleaning.
Note: the cleaning procedure is totally a rip-off (around $1000) and needs to be done periodocally. On the other hand if can eliminate this thing happen, u will have clean valves and also clean turbine, hoses, intercooler, pipes etc.
The PCV valve in 116i/118i is located right before the turbine.