Whining noise mercruiser 4.3

lukepetrinec

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Aug 24, 2011
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I just purchased a 2005 stingray with a v6 4.3L mercruiser. The boat only has 55 hours on it. On the second day out with the boat I noticed a whining noises coming from the far back side of the engine. The noise is only really noticeable around 3000rpm to 3500rpm. Any lower rpm and you don't hear it and higher the same thing. Any ideas what could be making the noise? Also smell a hint of gear lube smell occasionally.
 

dubs283

Vice Admiral
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Jul 27, 2005
Messages
5,058
Re: Whining noise mercruiser 4.3

the usual culprits of a whining noise are your power steering pump or alternator, both of which are located the the front of the motor

as far as locating the noise at the rear of the engine especially at higher rpms would indicate the noise is quite loud??

could you possibly post a video with good audio?? - not the best way to troubleshoot but this board does have its limitations
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,092
Re: Whining noise mercruiser 4.3

have you checked the drive oil level. if its below the top vent plug, pull the drive. I`m sure you`ll find oil in the bellows.
 

lukepetrinec

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Aug 24, 2011
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Re: Whining noise mercruiser 4.3

The sound is fairly loud, definitely coming from the back. At high rpms it drowns out and goes away. I'll see if I can get a video of it this week. I'm also going to grease the gimble bearing and the engine coupler and see if that helps. This being my first inboard/outboard in not sure if it should sound the way that it does. I don't feel like it should. I didn't notice it the first day out either. Come to think of it I didn't even notice it the second time out either, someone else in the boat did. But after they pointed it out I heard it clear as could be.

the usual culprits of a whining noise are your power steering pump or alternator, both of which are located the the front of the motor

as far as locating the noise at the rear of the engine especially at higher rpms would indicate the noise is quite loud??

could you possibly post a video with good audio?? - not the best way to troubleshoot but this board does have its limitations
 

lukepetrinec

Recruit
Joined
Aug 24, 2011
Messages
3
Re: Whining noise mercruiser 4.3

Drive oil reservoir seems to be at the proper level.


QUOTE=Bt Doctur;4195557]have you checked the drive oil level. if its below the top vent plug, pull the drive. I`m sure you`ll find oil in the bellows.[/QUOTE]
 

dubs283

Vice Admiral
Joined
Jul 27, 2005
Messages
5,058
Re: Whining noise mercruiser 4.3

I'm also going to grease the gimble bearing and the engine coupler and see if that helps.

thats always a good idea, the gimble bearing if bad would be quite grumbly at all rpm, and very noticable at idle speeds

the coupler i highly doubt is the culprit, they dont usually make noises, they just fail

best way to grease the coupler is to pull the drive and grease it from the aft, and also check the engine alignment
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,092
Re: Whining noise mercruiser 4.3

smelling gear lube inside the boat could be from the bellows having oil in it and leaking inside the boat.
 
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