Oil sludge in raw water basket

[Buzby]

Hi guys,
I changed the impeller on my KAD32 a couple of weeks ago. I’ve only used the boat for 5 hours since.
Yesterday I checked oil, water etc ready for a trip today. When I checked the raw water basket I was surprised to see what seemed like oil sludge in the basket mesh. I cleaned the basket and ran engine up for ten minutes or so and all seemed ok, however I’m concerned that oil may be getting into the impeller housing from the pump, is this possible? And could I have caused this problem when changing the impeller?
Any advice this brains trust can offer will be much appreciated

 

[vyv_cox]

Not knowing exactly how the pump is driven I cannot say for definite but it seems most unlikely. Raw water pumps that are camshaft driven have bearings that are lubricated by crankcase oil but normally not at pressure, simply the oil that has left the forward camshaft bearing at just about atmospheric pressure. Thus it is most unlikely that oil will be driven into the pump.

However, on most raw water pumps there is a tell-tale hole between the drive and the pump to detect failure of the water seal. If the oil seal on the engine side had failed, oil would emerge from this without reaching the pump.

 

[Buzby]

Not knowing exactly how the pump is driven I cannot say for definite but it seems most unlikely. Raw water pumps that are camshaft driven have bearings that are lubricated by crankcase oil but normally not at pressure, simply the oil that has left the forward camshaft bearing at just about atmospheric pressure. Thus it is most unlikely that oil will be driven into the pump.

However, on most raw water pumps there is a tell-tale hole between the drive and the pump to detect failure of the water seal. If the oil seal on the engine side had failed, oil would emerge from this without reaching the pump.

Thanks for reply. Decided not to venture out today just in case. Will check tomorrow to see if any oil at the weep hole you described