Question
My sprinkler system makes a intermittent shuddering sound when it operates (not just when it turns off or on).  I can hear it in the house and in the yard where the pipes are underground.  When this happens, the water coming out of the sprinkler head is very low.

What could be the problem and how do I approach fixing it?

Thank you,  Leslie

Answer
Hey Leslie, I hope this helps. It sounds like your diaphram in the valve is going out and needs to be replaced. Basically the diaphram is the piece inside the valve that raises and lowers to turn the valve on or off. To access this piece you will notice on the top of the valve a series of screws, once you take oot these screws, the top half of the valve will be separated from the bottom half, and the diaphram will come out. You will need to know the brand and model #, and also the size of the valve, to match up the new diaphram. Any irrigation supply store should be able to help you out. Good luck and have a great day.