During this weeks maintenance it was noted that the engine temperature was slightly warmer than normal. The raw water pump is directly under the companion way steps and easy enough to inspect. After removing the cover plate it was visible to see the reason for the increase of temperature was due to the decrease of water being pumped through the system. After inspecting the impeller it was noted that five blades were damaged but all were still attached. Still having a complete impeller gave relief to knowing that no pieces were pushed down stream into the tube bundle inside of the heat exchanger.
It has been 199 hours of service time with this impeller. Also note worthy is that the majority of that time has been on the inland/near shore waterways. Dirtier and higher chemical p.p.m. reduces the service life of pumps. While the pump was partially disassembled it was decided to swap out the double bearings, inner o-ring, and inner seal. Simply stated a major rebuild kit was used.
With a new impeller installed and the log book updated, the Perkins is now running back at the expected temperature.
Pump: Sherwood G65
Major rebuild kit: around $90
Rebuild time: around 2 1/2 hours