The toilet in a second floor bathroom started making a terrible noise when flushed. It sounds like a pump running dry. Very loud, stuttering noise. Seems to be coming from the fill valve BUT even while making the noise, the tank is still filling up, although slower than normal. If I wiggle the float rod a little the noise stops. Anyone have experience with this and know what part(s) I should replace?
Sounds like the internals of the fill valve are just a bit loose. Happily, toilet guts are pretty standard unless you’ve got one of those odd “hatbox” or ultra low profile things, and you can get a fill valve for about ten bucks. 20-25 bucks will get you a complete rebuild kit with a flush valve/flapper and maybe even a new handle.
You’ve already diagnosed the issue. Go buy one of these. (or a comparable product)
The fill valve is obviously undergoing some kind of oscillatory failure mode.
Might be partially blocked, might just be worn parts or a weak spring or countless other faults. Who cares. $10-$20 and you can replace the whole kit and caboodle. Notice how the kit includes new flapper valves as well, since the rubber deteriorates over time when exposed to chlorine.
If you feel like replacing every single part in the whole darn toilet tank, another $10 is all it’ll cost.
Sometimes the shutoff valves fail open, by the way. That’s a bit trickier to replace. Just make sure the shutoff valve works before you start messing with it.