Engine sound after flushing toilet

[YtaminM]

Hard to describe the noise but my toilet makes this engine sound after I flush. It doesn’t sound like foghorn or hissing to me but please have a listen the video I posted.

I found some videos on YouTube which suggested this could be from vibration noise from toilet water valve due to air pressure difference. I tried their method of closing the main water valve of the house in the basement, then opening all the faucets in the house to let the water drain from the pipes, which would supposedly clear the air/equalize the air pressure in the pipe, and that in turn would get rid of the vibration noise.

Well it didn’t really work for me at all. I’m wondering if anybody knows what may be the cause of the noise and how to fix it.

Thank you

 

[Twowaxhack]

Replace the ballcock. Watch some videos on how to do that.

Buy a Fluidmaster 400a

 

[YtaminM]

Update: it seems that the cause of the sound is from faulty toilet water supply shut off valve. It kept spinning and wouldn’t shut off when I tried to close it. At the fully opened position it probably let in more water than the fill valve could handle, causing pressure to build up which lead to the loud sound. Once I was able to fix the shut off valve, I closed the valve to lower the fill rate, and the engine like sound disappeared after flushing.