» Whenever I flush the toilet upstairs the pipes make a loud rumbling noise downstairs, right as it is finishing the Leon Alpharetta, GA 09.17.11 » flushing cycle. Any ideas on what is causing this and how i might fix it? Any help is greatly appreciated. Hewitt Remodeling Service... Virginia Beach, VA Leon, Lots of good suggestions but I think we are all making some assumptions without doing a bit of troubleshooting first. When you say "right as it is finishing the flush cycle", are you talking about it making a noise as the water finishes leaving the bowl (drain plumbing side) or are you talking up to a minute later as the tank is filling back up (supply plumbing side)? If you aren't sure, turn the shut-off valve off. This will prevent the tank from filling back up. Take the tank cover off and set it safely aside. Now flush the toilet. If you hear the noise, the problem is with the drain side of the plumbing. If you don't hear the noise, open the shut-off valve which will allow the tank to begin to fill again. Pay close attention to when you hear the noise....as it starts to fill.... or the whole time it is filling...or when it gets close to being full. Is it a rumble/banging noise or a "squeak" noise. That information will help narrow down the cause of the noise and thus get you on the right track with correcting it. Let us know what you find out.... Tim [?] Leon Alpharetta, GA Thanks, Tim. The rumbleing occurs right at the time the tank completes a refill after flushing. Everything has flushed and it is the very last thing that occurs.The noise is a loud rumbling noise that occurs and cuts off abruptly. Thanks, Leon [?] Jason W Athens, GA your pressure is too high this is what i do iam a service plumber [?] Hewitt Remodeling Service... Virginia Beach, VA Leon, An explanation for asking the questions that I did in my previous post may be in order. At a young age my father and grandfather taught me to troubleshoot problems properly. In my former "life" in Naval Aviation, the penalty for making unqualified assumptions and jumping to conclusions was costly at best and at its worst, deadly. If we ask the right questions upfront, we can focus our attention in the right direction, thereby utilizing the tremendous talent and experience found here on Hometalk more effectively. If we offer advice without further explaining the "why", we have missed an opportunity to help someone get a bit smarter. Thanks to your basic troubleshooting, you have successfully narrowed the problem down to the supply side of your plumbing. It could be just the cold side is impacted and could be just a section of the plumbing, but there is no easy way to accurately troubleshoot that further than you have. I would, however, be curious if you get the same noise when you quickly shut the cold water off in the sink in the same bathroom. I don't pretend to be an expert...and I fell asleep during the discussion of the basics of hydraulics. So just a few comments/suggestions. I am sure you have figured it out by now, but that noise you hear is caused by the sudden securing of water flowing thru the pipe. "Why" is the question. This can set up a sort of "shockwave" to the system which causes the movement and therefore the noise at a "weak-point". You can sometimes see this similar action when you suddenly release the handle on a garden hose; the hose seems to "shift" or "jump", although it is often imperceptible because of the flex in the hose. It could be that the section of pipe that is "rumbling" is not secured properly. It is possible that the overall water pressure in the house is too high; but generally when this is the case you get the symptoms in other locations/scenarios with other fixtures as well. This can easily be measured by a $5 pressure guage from one of the box stores hooked to one of your hose bibs (outside water faucets). It could be you have an air "dampening" system in your supply plumbing that is supposed to be filled with air and acts as a shock absorber that has failed (you can look this concept up under "water hammer"). The simplest and least expensive thing for you to do, as mentioned already by other members, is to change out the fill valve in the toilet. Strangely enough, some pipe noises require a certain "frequency" to set up the vibration that makes the noise. The way or rate that your existing fill valve is closing, combined with the water pressure, can cause the noise. Replacing the fill valve with a new one could stop the noise, either by avoiding that "frequency" range or by shutting off the water slower so the pipe system can handle the more gradual change in water flow. If that doesn't work, it is probably best to bring in a pro. Constant "hammering" (if that's what the noise is), can in theory over time damage weak points in your system. Tim [?] Jason W Athens, GA changing the flushvalve or putting more clamps on the pipes wont help check the water pressure at a hose bib it sounds like you need a p r v [?] [?] Advertisement bathroom ideas bathroom ideas Powder Room Ideas Kids Bathroom Ideas Pretty Bathrooms.