I had a funny knocking or thumping sound every time I turned on the kitchen faucet. I replaced the sprayer thinking it was that because the hose was cracked and I thought maybe it got air in the line some how. That made it worse. So I replaced the whole faucet with a new sprayer. Now I'm back to the occasional thunking sound I started with. Could it be something in the water line going to the faucet? It doesn't do this on any other faucet of the house.