My vent pipe sounds like a wind tunnel

[Vicky T]

I live in a mobile home. The vent pipe goes up to the roof. Last night, all of a sudden I flushed the toilet and it sounded like a wind tunnel and the toilet filled very slowly. Wind tunnel the entire time. In addition I lose pressure in every other sink and tub while this goes on. I went outside to see if there was leaking underneath. There was not. The wind tunnel sound was indeed the vent pipe. Very loud outside as well. What could be happening? The problem continues and also happens when I flush a second toilet in the master bathroom.

 

[FullySprinklered]

Sounds like your PRV is dying and taking the expansion tank with it. If you have an expansion tank. It's likely a pressure issue, in short.
Pressure problem noises vary quite a bit. Anything from a tapping noise to a groaning lovesick whale sound.