Vibration in cooling water hose to raw water pump

Lennyd123

Seaman
Joined
Aug 1, 2005
Messages
62
Finally got the Ole Sea Ray launched with a new through hull cooling water pick up and true sea ****, and it seems all the previous demons are now gone and it is running smooth (minus an occasional miss lol) but when checking over the thru hull assembly I noticed that the entire 1-1/4 hose has a very high pitched constant vibration.

I have no idea if this is normal as I never had a reason to touch the hose before and I know that the pump itself is not the most precision part either, but it seems a bit odd to have those vibes leading to a fitting that is sealing water from entering the boat so I wanted to hear some thoughts on this.

Now there is also a small wine that sounds like or similar to that of a PS pump and it has been there since the last rebuild of the engine and was close enough that one mechanic thought that the PS pump could have been a part of my previous engine vibration problem that ended up being an a flywheel that was installed in the wrong position. Note that the noise was not present in the original engine or previous to a year ago etc.

Also though the new water pick up seems to work great and the gauge shows the temps lower than before etc it still climbs at planning speeds and even though the risers remain cool enough to hold your hand on them, and even the manifolds at lower engine speeds so I think it is getting enough cooling water supply.

Appreciate any thoughts and ideas and thanks in advance for your help.

The engine is a rebuilt 7.4l 454 orig 330hp w a bravo 1 drive.
 

Lennyd123

Seaman
Joined
Aug 1, 2005
Messages
62
Re: Vibration in cooling water hose to raw water pump

I checked it out again today and it really is sort of weird in how sounds like the noise is like the humming of a PS pump, but the the pump is quiet and vibe is only felt at the raw water intake hose.
 

Failproof

Petty Officer 1st Class
Joined
Sep 26, 2011
Messages
273
Re: Vibration in cooling water hose to raw water pump

Well power steering pumps are vane pumps, and your water pump is a vane pump. They will both have "pulses". Somewhat akin to small water hammer. Your intake hose is seeing fluctuations in vacuum cause sudden drop and rise in flow. That causes a harmonic distortion, a vibration and a noise.
 

Lennyd123

Seaman
Joined
Aug 1, 2005
Messages
62
Re: Vibration in cooling water hose to raw water pump

Well power steering pumps are vane pumps, and your water pump is a vane pump. They will both have "pulses". Somewhat akin to small water hammer. Your intake hose is seeing fluctuations in vacuum cause sudden drop and rise in flow. That causes a harmonic distortion, a vibration and a noise.

Sorry for the delayed reply, but somehow I never received an alert that there was a post etc.

That makes sense, and since I am not having any problems after several trips (sort of short ones for various reasons, but typically 2 hours total avg each) it seems that there is not any immediate problems with the pump.

I do have a spare impeller and may install it just to be sure there is not any problem etc, but will likely wait until I have something else to tackle in the bilge like the second bilge pump that has not worked correctly since the first rebuild went in years back.

Thanks for the input !!
 
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