Do you have a noisy swimming pool pump? If your pump sounds like this you have bearings that are worn. This is usually the cause of water leaking from the shaft seal and getting into the motor to rust out the bearings.
Always get leaks fixed ASAP. Shut down your pump until the necessary repairs can be made by a qualified technician.
Many pool companies do not change bearings on swimming pool pumps. They simply tell you your motor is shot and sell you a new motor. In many cases this is the best solution but in some cases you can save two thirds the cost by changing your bearings and seals. To give you an example, the average motor repair on a 1 horsepower motor is a little under $340 and bearings replacement is $95 installed.