"Christopher Flores" wrote in message
et...
I have been trying to diagnose a plumbing noise problem
with no success and would appreciate some more seasoned
advice.

When I open the upstairs bathroom sink cold water faucet
just a little I get a strong loud vibrating sound. It goes away
as I increase the water flow.

No problem with the hot water faucet or downstairs faucets
(hot and cold). I first thought it a hammer problem but that
supposedly only happens on closing faucets and anyway I
did bleed the system to all air back into the air chambers.
But this ghoulish noise persists.

Google for "seat chatter."