Engine Compartment Noise

[rt11002003]

Granted, boat with engine boxes are noisy. Nature of the beast.

I have a howling noise, increases with rpm, but finally reaches a max. Reminds me of an alternator whine/howl, or maybe something in the gearbox. Is anyone else having this experience?

Gene

 

[doke01]

turbo? or maybe alternator belt?

 

[Kamalani]

Gene - is howling noise present with the shaft turning, or with the eng. in neutral or both? Possibly a tight or dry stuffing box? You have checked the gear oil level, right? What about a pump impeller, or bearings in pumps or alternator?

 

[rt11002003]

The oil level in the gearbox is OK.

The howling isn't present when I do the max rpm cycles before shutting down. doke01, that rules out the alternator and these little engines don't have turbos to make noise. Thanks for your input, it helps in my thinking to hear other's thoughts.

That cycling would indicate the driveline is making the noise.

I need to explore this further.

Gene

 

[bbrh842]

At certain rpm's, a quite noticable high pitched ringing sound comes from near the stern of my boat. It turned out to be the blades on the prop vibrating in resonance with the rest of the drive train. This was confimed by hitting the blades of the propeller with a blast of water from the hose while the boat was out of the water. Makes the same ringing sound. I wouldn't describe the sound as howling though, more like the sound the propeller would make if you tapped the blade with a hammer.

 

[Andrew Custis]

Gene,

This is the response I got from my Yanmar guy. Let me know what you think.


Andrew



I am assuming that this is not a complaint that you normally get so possibly something is different or going wrong on with this one.



There is no comment if it does it in and out of gear and both in forward and reverse etc.



Possibly the alternator belt is loose and slipping, no comment where he is located but probably should have someone look at it in case it is something that might break.

 

[Andrew Custis]

Gene,

My apologies today on the phone. Did not go well after I talked with you 😀 I will get my phone charged up in the morning and give you a ring. Talk to you soon!