Chugging noise in water pipe

The water supply line that feeds the washer and an upstairs bath has started to make a chugging noise when the cold water is run with any valve near the fully open position or when multiple taps from the affected line are run. Does not affect any other part of the house. It appears to be caused by some sort of surging of the water pressure in this particular line. This is confirmed by looking on the water meter - the needle speed varies with the chugging. No pipes are moving and it is not water hammer. This problem began about a month ago, but there were no changes made in the pluming that could have caused a change.

Does anyone know what might be causing this problem and what the best solution is?

noise

The chugging noise probably IS the water meter. Or at least its sound while it is measuring the water flowing through it.

chugging

If it is the water meter - then why does it not make noise with any other water use? Even the outdoor sprinklers that use a 3/4" line and alot of flow - do not cause the chugging. But if you run a tap or flush a toilet on the one affected line - then you hear the chugging. The noise is fairly loud and extends through the affected pipes. The surging of the needle at the meter leads me to believe that something in between the meter and the outlets is rapidly varying the pressure.

noise

The only thing that can vary the pressure would be something that varied the volume, and about the only thing that could do that would be something that "opened and closed" in the pipe to change the flow.

chugging sound

I agree, that's why I am stumped too, but there is nothing turning on or off. Is it possibly caused by a restriction somewhere in the pipe?

surging

Would there be a stop and waste valve or a globe valve in the cold line in that area ? If there is, there could be a loose washer that could move back and forth. Could air be getting into the supply in that area?