View Full Version : Low RPM water pump squeal
02-19-2009, 02:37 PM
I have a 1989 pro star. In preparation for the season I started it up today. It started and seemed to run fine except for a squeal coming from the water pump at idle. When I raised the RPMs slowly the squeal went away completely at 1200 RPM and everything seemed fine. However when I back off to idle the squeal returns. I ran the engine at 1200 RPM for about five minutes and saw the temperature slowly get to normal but when I dropped back to idle the squeal resumed. I've had the boat for 20 years and never heard this noise. Any ideas?
02-19-2009, 03:16 PM
Could be the belt.
Spray, splash or drip some water onto the belt and/or pulley. If it goes away, it's the belt. If not, it could be the impeller and that should be checked. If it hasn't been changed recently, it could be due to the decrease in flex by the vanes causing it to draw less water in at low RPM and then running dry and squealing when the rubber is in contact with the housing.
02-19-2009, 03:33 PM
Check the raw water pump impeller. I have found that is a clear indication it may be time to replace if it hasn't been replaced recently.
02-22-2009, 03:03 PM
check the belts , but sounds like the bearings may be wearing in the raw water pump.??