Volvo d13, when accelerate i hear sound like air coming out of somewhere, and the gas pedal for just

Volvo D13 gas pedal not responding for a second and like air coming out of somewhere, when accelerating and in high rpms. As well when i let my foot of the pedal and shifting into 10th gear, it does this couple of times a day, any help would be greatly appreciated, Took it to few mechanics couldn’t figure it out what is it, no codes as well or check engine light. The sound coming out from the Driver side, no visible leaks as well.



Thanks

 

I’ll tell the mechanic to have a look, thanks, altough i have replaced the intake presure sensor and the venturi pipe, when i took the truck from the mechanic after a day started doing this, and it bothers me sooooo mich