Noise after replacing impeller and fuel/water separator

[rossbar86]

I just replaced the impeller and fuel/water separator today and now notice a sort of rhythmic "brushing" or "scraping" sound. Can anybody help identify this noise? Is it a belt issue?

View attachment IMG_3610.MOV

 

[MarineSp]

That rhythmic brushing sound is almost certainly the impeller itself. Most likely causes:

• Impeller blades installed backwards (they need to curve in the direction of rotation)
• One blade folded back during installation and scraping the housing
• Housing cover not seated fully flat, causing slight contact

Pull the impeller cover back off and check the blade orientation first – it's a 5 minute fix if that's the issue. Also check that you got all fragments of the old impeller out; leftover pieces can cause exactly that sound.

 

[rossbar86]

That rhythmic brushing sound is almost certainly the impeller itself. Most likely causes:

• Impeller blades installed backwards (they need to curve in the direction of rotation)
• One blade folded back during installation and scraping the housing
• Housing cover not seated fully flat, causing slight contact

Pull the impeller cover back off and check the blade orientation first – it's a 5 minute fix if that's the issue. Also check that you got all fragments of the old impeller out; leftover pieces can cause exactly that sound.

Thanks! It was my first time replacing the impeller so very well may have foolishly installed it backwards...thanks! The previous impeller was well intact and didn't see any fragments in there but I'll take a look.

 

[Horigan]

Impeller blades self-orient to proper direction, so you don't need to worry about which direction they go in, assuming you installed the correct impeller. As suggested, make sure you removed any old impeller pieces in the system. Put your hand on the pump while running to see if you can feel the noise. Otherwise, pull the impeller and see if there are any signs of unusual wear in the pump body.

 

[rolmops]

Impeller blades self-orient to proper direction, so you don't need to worry about which direction they go in, assuming you installed the correct impeller. As suggested, make sure you removed any old impeller pieces in the system. Put your hand on the pump while running to see if you can feel the noise. Otherwise, pull the impeller and see if there are any signs of unusual wear in the pump body.

Mmmm, interesting....
When inserting the impeller, use some form of lubrication (soap) and turn the impeller forward in the direction of rotation clockwise while inserting it. When properly installed, the tips of the fins should be bending backward when the propeller moves forward.

 

[rossbar86]

I just started it up and it sounded fine at first, then the sound came back. It almost sounds like it is coming from the power steering pump?

View attachment IMG_3623.MOVView attachment IMG_3624.MOVView attachment IMG_3626.MOV

 

[rossbar86]

Okay, maybe it just needed to run a while b/c I let it go for 5-10 mins and everything seemed to sound just fine. I even used a stethoscope on the water pump, alternator and power steering pump and nothing sounded odd or the brushing / scraping sound wasn't even present

 

[Horigan]

Mmmm, interesting....
When inserting the impeller, use some form of lubrication (soap) and turn the impeller forward in the direction of rotation clockwise while inserting it. When properly installed, the tips of the fins should be bending backward when the propeller moves forward.

That's how I do it also, but if you inadvertently install the vanes in the wrong direction, they bend in the right direction as each vane passes the portion of the pump housing where the vanes full extend. Shoot, some engines that briefly run in reverse when shutdown (dieseling), do this every time they start up.

 

[Horigan]

Okay, maybe it just needed to run a while b/c I let it go for 5-10 mins and everything seemed to sound just fine. I even used a stethoscope on the water pump, alternator and power steering pump and nothing sounded odd or the brushing / scraping sound wasn't even present

Great! Maybe cycle the steering wheel back and forth with the engine running to ensure any air in the steering system is purged. I'd keep an eye on the fluid levels. Air should not be getting introduced into a good tight system.