[xtac1080]

Hi there guys, the car's problem is fuckin bizarre.So, by checking all possible causes, my brother unfilled the oil cap and BAM!, car idling again!We had some fun with covering the hole for a few times.Actually the vacuum created there was so great when I was accelerating that my brother barely could lift his palm from the oil cap.We stopped the car and when we started it again, it continued to idle flawlessly even if we put back the oil cap.We are indeed baffled because since then the car runs as it should and I couldn t reproduce the issue that the car had for over a year.I leave the videos to see for yourselves.Anybody, any idea? I m guessing some kind of throttle body glitch,I don't know.It has to do it again to investigate further.
So,with oil cap off : https://www.youtube.com/watch?v=leJ-cvZVohQ
After 10 minutes with oil cap on, running smoothly : https://www.youtube.com/watch?v=jySQ4gjPqWY

How many miles on the engine? I highly recommend you pull the intake manifold and check the amount of carbon that has built up on the backside of your intake valves. Direct injection only motors are notorious for carbon build up, and it can cause the intake valves to stick creating all sorts of fun side effects (backfires, misfire with no codes, etc). Maybe do a compression test to ensure the rings are good as well. It sounds like you may have dislodged a stuck/sticking intake valve when you released the negative crankcase pressure (opening the oil cap with engine running).

Here is an excellent video:
LINK
I linked it to the time in the video pertinent to you, but I highly recommend the entire video.