Today when i went to check the oil level of my citroen c5 I noticied that oil came out of the oil cap. I bought the car in August 2018 and since early it was showing anti-pollution fault warning on and off, however during the winter the anti-pollution faul warning very rarely shown up, but since the hot weather came it is always showing the warning and sometimes when the car is on neutral gear cuts off.
What do you think the reason of the oil coming out of the oil cap?
I am also posting a picture so you can see the problem
Thank you