Our tub faucet just started making a loud, low pitched noise (like a foghorn) when we turn the water on or off. It happens when there is not a lot of water running through the pipes and stops when we turn the faucet up higher. It happens with both the cold and hot water. Does anybody know what causes this and how to make it stop? Thanks!

Loose washer in tub valve, since its both hot and cold it must be washer on diverter stem.

Loose washer in tub valve, since its both hot and cold it must be washer on diverter stem.
The widget maker nailed it again, Perhaps this will help. (see image) Good luck, Tom