gasoline engine making air

& nbsp; & nbsp; Guys the other day, I asked a master in the industry to look at the engine of my Peugeot 1.4 petrol sedan comfort model just for control. While the car was running, he opened a black cover on the engine and left it on, then said that the engine made air. On the other hand, the engine I learned with hearsay information is only in diesel vehicles. I wonder if you would inform me about the subject. And what are your suggestions if the engine has aired? respect ...

On diesel vehicles, when the fuel system runs out of fuel, & nbsp; air is generated & nbsp; in the air instead of fuel, the vehicle will not start. In our vehicles & nbsp; cooling system does not get air when filling the cooling water, it will circulate with the water in the system and full cooling will not be provided. After looking at it, he did not understand why he made flu and he did not understand why.

our masters here is a strange I am in the southeast. Unfortunately, most of them do not understand the job, the master is difficult in the master. Thanks to your interest, my friend.

Which black cap? A small cap or oil-filled cap?