Volvo "Breather Box"/PCV System Replacement!

Hello,

The noise that I hear is loud, I actually feel my car vibrating when I step on the gas and when I put my car in park it actually gets worse as if someone is pressing on my gas. When I’m driving, I dont really hear the noise as much or my car vibrating. As far a oil, my car is not leaking any oil and it has not leaked any oil before I took my car in. Even when I took my car in and told them about the issue, the machanic “said that he found a hole in my “breather box or vent box” and said that he really cant show me the hole because it would be kind of hard to see and that its under another part on my car”. My car was fine before I took it in…they said that it would be $700 to replace the breather box…Can they patch up the hole, or is the hole that he is seeing apart of the breather box, which allows air pressure to release…