Recently my toilet water supply line began making a groaning/vibrating sound after the cold water in the bathroom sink was turned on, then back off. This was especially true when the toilet was refilling. I have implemented a poor solution by turning the supply valve so far down that it takes the toilet a half hour to fill back up. This takes care of the noise but is obviously a problem. With the hose disconneted from my toilet and get a noise if I open the valve up at all. With the hose connected I can get the noise to cease by lifting the float inside the toilet tank or turning the sink back on. Is the supply valve bad? Thanks.