About 30 seconds after I flush my toilet, I hear a loud, vibrating noise, such as shutting an old iron door sound, that comes from my basement, not my toilet.

Suggestions?

Could be a bad house pressure reducer. Look for it and have someone flush the toilet and listen.

I don't know where that is! I am a single Mom and stupid when it comes to plumbing! I did go downstairs to listen, while I had my son flush. I could not really hear where it is coming from. It is my master bathroom toilet, on main level. I actually hear it more when I'm in the family room, in the back corner of the room.

I read a similar post about adjusting the ballcock. Could I have the same issue? I pray this is a simple fix, because I can't afford to put anymore money in my house. I just had to buy a new furnace a couple of days ago... everything is falling apart!
Sorry~ a tad stressed.. thank you for all your help!

I am not having a problem with water pressure. Just the noise! Does that make a difference?

Does the noise only occur when you flush that toilet and not when you flush another toilet or let a faucet run?

I would suggest repairing, or simply replacing the fill valve in the toilet.

Do you have a PRV valve, (see image) installed where the water enters your house? Back to you, Tom