Pool pumps and filters should operate relatively quietly, if properly installed and maintained. But over time -- or if improperly maintained -- pool pump motors can become loud. A loud pool pump motor is not only unpleasant to hear; often a loud pump is not cleaning the pool water properly. If your pool pump motor is making loud noises, it's time to troubleshoot the filtration system to find out what's causing the noise.
Check the pool pump and filter base to see if it was installed on level ground. If the filter system is sitting on an uneven base or on ground that's not level, the internal moving parts of the pool pump will cause the entire filter and the motor to vibrate. Sometimes solving the noisy pump is as simple as securing the base for the filtration system.
Clear the pump basket and skimmer basket with a garden hose. If these two baskets are filled with debris, the pool pump motor must work twice as hard to suction the water from the pool and push it through to the filter. When the motor is overworked, it will make noise. Keeping the basket areas clean will reduce pump motor noise.
Examine the pool pump impeller. To examine the impeller, turn off the filter, unplug the pump and open the pump basket lid. Pull out the pump basket and reach your fingers down through the tube leading from the pump basket toward the impeller. Touch the impeller to see if it's clogged with debris or if it is wobbly. Too much debris or a wobbling impeller will cause the pump to sound loud. Remove the debris if it's dirty. Use a pliers to bend a stiff piece of wire to create a hook at the end. The hook will help you remove debris. If the impeller is wobbly, you may need to have it adjusted or replaced.
Replace the bearings. If you hear a whining sound in the motor, it's time to replace the bearings. This is an intricate process, so take it to a technician familiar with the inner workings of a pool pump motor.
Raise the pool water level. If it has fallen below midheight of the skimmer faceplate, it is possible that air is getting into the pool filtration system. When air gets into the pump, it disrupts the pump's vacuum environment needed to filter the water. It puts more of a strain on the pool pump, causing it to sound louder as it works harder. Adding water to the pool will resolve the problem.