Loud hammer noise with faucet, not sprayer?

[Sophia777]

Good day! I just replaced a kitchen faucet and a brand new issue has appeared. There is a water hammer noise and vibration when I use the faucet but the noise/vibration stops when I use the sprayer. The on/off water valves underneath are fully open. When the faucet tap is open, the sprayer dribbles. Is this a defective sprayer diverter on a brand new faucet? What could be causing this and/or how can I fix this? Many thanks for your time & input!!

 

[Sophia777]

Just adding a bit more clarity. I had a plumber come to replace the faucet. After finishing, the sound appeared. He felt it was likely an old valve not allowing full flow. He showed me how the hose was pulsing water (in a bucket) when not connected to the faucet. Are the issues all tied together, and/or do I have an old bad valve under the sink AND bad diverter on a new faucet? Or can the valve cause the noise and a drippy sprayer (only when tap is open)?

 

[Burnetplumber]

Bad diverter

 

[Geofd]

If it’s pulsing with no connection to the faucet, sounds like a loose washer in the shut off valve most can be rebuilt

 

[Jeff Handy]

Sounds like you have both issues, bad valve and diverter.

You might be able to learn which valve by closing one at a time.