I recently replace the sink sprayer head in our kitchen sink because it was old and leaking.

This sink sprayer has begun doing two things that is driving us nuts and I can’t seem to discover what is causing it.

#1. My wife will be in the kitchen rinsing off dishes with the sink sprayer and suddenly I will hear from the living room a rapid fire du.du.du.du.du.du.du.du. That sounds similar to a burst from a 50 Cal machine gun only not as loud. My wife says this rapid fire pulsing and fluttering noise is also accompanied by a matching rapid fire flutter of water from the sprayer head.
This has happened several times but when I try to duplicate this action for myself I can never get the sprayer to do this.

#2. Secondly, my wife says she will be using the sprayer and it will be spraying a nice strong spray and suddenly and gradually the spray stream will become weaker, and weaker, and weaker until it is spraying only half the distance and with half the pressure that it did initially when she turned it on. I have gotten the sprayer to do this for me as well.
I notice when I remove the sprayer head and turn on the water that a nice steady stream of water shoots from the hose without any noticeable loss in stream pressure or distance.
I also notice that when using the sprayer and then release the sprayer button the water will then divert back to the main sink spout as normal and the spray coming from the spout seems strong and steady with no noticeable loss of stream pressure at all.

I have checked for leaks and kinks in the sprayer hose connections and there are no signs of leaks or kinks anywhere under the sink at all. The hose is unobstructed so that it can move freely.

I am pretty handy and can fix most anything but this problem is driving me nuts.

Not a Plumber, 2 things come to mind, something in the sprayer line.
Remove and try to clear.

2nd is Dampers(air chambers) for anti knocking/banging, from what a plumber told me years ago was to turn off water, and open faucets to allow the air chambers to drain the water.
A couple of great Plumbers here will likely add some more accurate info.
Good Luck, Let us know how you do.

First find out if your wife's machine gun is firing hot bullets or cold. I doubt that they are 50 caliber. If they were you wouldn't be here.

What you describe sounds like a loose washer in a stop valve. Since your wife is probably using a mixture of hot and cold water to rinse, next time it occurs have her quickly change to either all hot or all cold. Do not stop spraying.

That may give you some indication of whether it's the hot or the cold stop valve that has the loose washer. You could just replace both the hot and cold stop valves to see if that corrects the problem. They are not that expensive.

If replacing the stop valves does not fix the problem, replace the sprayer head just in case it is defective. Doesn't sound like it but indications are that this problem started with the new sprayer head.
If replacing the stop valves and the sprayer head doesn't fix the problem the only thing left will be the diverter valve in the faucet.

If all else fails the final solution will be for you to do the dishes.

Sounds like you have a partially clogged spray head. Since everything is good with the head removed, but not so good with the head on, you can either try to clean the head assembly or simply replace it. Im betting this will resolve the issue. With a partially plugged spray head, it will cause the spray diverter (located in the actuall faucet body under the faucet spout) to hammer back and forth creating the sound you describe. If when you use the spray, a good amount of water is still coming out of the spout, then you have either a stuck diverter (not likely since you have good water out of the hose to the head with the head removed) or a plugged up head. I would suggest cleaning or replacing the head, as well as cleaning or replacing the aerator on the end of the spout (if the head is clogged up, Im betting the aerator is too) Low priced parts that are easy to swap out, and result will surprise you.

Thanks guys for your help!

Tonight I worked some more on the problem and checked the aerator on the sink faucet spout and also took the head off the sprayer and both seem to be clear and flowing freely.

I played with this for an hour and could not get this to do any of the rat-a-tat-tat pulsating racket that I mention earlier. However, I noticed when working on this tonight, when running only the hot water side of the sink I will get a nice strong flow out of the main spout and then when I activate the lever on the spayer the water diverts nicely with no water flowing from the main sink spout at all. But……after holding down the spray head lever the nice strong spray begins to slowly get weaker, and weaker, and weaker until the spray stream is only 1/4th of what it started being. And funny thing is…when I turn on the hot water faucet in the nearby bathroom I get a nice strong stream out of that spout.

Is it possible that this means it could be a bad stop washer in the hot side of the sink that could be causing this? Or, maybe still the diverter?

Thanks again for your help!

I vote for the stop valve, easy enough to change.

After checking out everything mentioned above I was at my wits end and just replace the faucet with a new one and PRESTO... NO MORE PROBLEMS.

I found all the seals, stop valves, etc, to all be fine and just could not figure it out.

Also, the faucet I had had no way to even get to the diverter valve, let alone replace anything on it.

After removing the faucet I could see a lot of hard water scale down inside the cavities of the unit, so since the diverter is the only part I could not view or access all I can do is just assume that the diverter was possibly being affected by chunks of scale or something.

I replaced the new faucet with a new one just like the one we had because my wife likes the tall 90 degree spout that is elevated high above the sinks so she can get her head under it to was her hair. The new faucet also came with a new hose sprayer and I noticed when installing the head on the hose that inside the threaded base of the head is a rubber washer with a hole in the center; and I noticed that the hole in the center of this washer was much larger than the hole in the center of the old sprayer head that I removed. And it occurred to me that this feature difference alone is going to allow a lot more water through the spray head creating a much more powerful stream; and that's exactly what it did.
The new one works beautifully.

Thanks again for all your help and suggestions.

Glad you got things all taken care of. Sometimes a new faucet is just the ticket to save the heartache of trying to fix the old one. Just out of curiosity, what brand of faucet is it? I have never seen a kitchen sink faucet with spray that didn't have a removable diverter. Normally you have to remove the complete spout assembly to gain access to the diverter, and honestly some of them can be a real pain.

Well I noticed at the base of the spout was a knurled cone shaped collar.
Out of curiosity and since I was replacing the unit any way and didn't care about damaging it, I put my channel locks on it and bore down with all my might and could NOT get that baby to budge an inch. I was determined to get inside this thing to take a look at the diverter valve. I even clamped the faucet base in my bench vice and put a small pipe wrench on it and ended up breaking the metal base at the collar base and nearly tearing the collar in half, but not breaking it all the way through.
By this time I was so frustrated with the thing that I just gave up and tossed it in the recycle bin.

Both the old one and the new one is the same model and brand name of Pfister.

This was the only one we could find at three of the big Lumber Yards hat had a tall 90 degree bend faucet. And it happened to be the cheapest unit of the all at only $49.00. But I figured what the heck... the last one lasted almost 13 years, so I'll just keep replacing them and feel I'm not out much. I put the last one in during the month of October of 2000 when we moved into this house.

I must admit, at that price, with you doing the work yourself (not having to pay somebody to replace it) you would almost have to be some kind of crazy to not just swap that sucker out, lol. Good job, and I hope you get another 13 years out of the new one.