Audi A5 1.8tfsi car reving up and down, strange noise on normal temp

[aljosagrega]

Hellow!

Could please someone help me. My car is reving up & down on idle and when it gets to the normal temperature a strange noise is coming from the engine. My mechanic is obviously not properly qualifed. The error the car is getting is sub-pressure. Links of video of the car reving and noise coming from the engine. Thank You!

Audi – Google Drive

drive.google.com

 

[NHN]

Clutch slipping?

 

[aljosagrega]

Clutch slipping?

On idle ? The mechanic said its getting 2 much air from somewhere

 

[aljosagrega]

On idle ? The mechanic said its getting 2 much air from somewhere

Also when you open the oil cover there is somekind of pressure, it sucks the cap right on