The answer to 'water line replacement making noise' is that a new water line replacement can sometimes make noise due to changes in water pressure, vibration, or the new pipes settling into place. This is common and usually nothing to worry about, but it's important to address any persistent or excessive noise.
Some common causes of noise with a new water line include: water hammer (sudden changes in water pressure causing pipes to shake), air pockets in the new pipes, or the new pipes rubbing against other surfaces. These issues can often be resolved with simple adjustments or additions like water hammer arrestors, air release valves, or pipe insulation.