Hey, I know it's almost impossible to diagnose a sound without hearing it first-hand but I figure it's worth a shot. My Merc has started making a gear whine type of sound at idle only while in neutral. Sound instantly goes away the second I put it in gear either fwd or rev. Previous owner said he had not done the water pump and he had the boat for 5+ years. There's good water flow but thought I'd mention it. Any ideas? Thank you in advance
2002 Mercury 90HP ELPT 4S
Serial #0T562954
Not understanding what gear whine means, but if there is a whine sound, could it be your compressor is going out?
It's the only way I know how to describe it. Like a whine but lower pitch, like a whirrrrrrrr
Last edited by tmusky1; 08-01-2017 at 05:13 PM.
Pretty sure the compressor is Optimax only.Originally Posted by Nutt
_______
Phil
'09 Hewescraft ProV
'09 150 Optimax
That's good to know. That's what I get for guessing. LOLPretty sure the compressor is Optimax only.
Check gear lube and engine oil levels.
Not just the "level"- but also the QUALITY of the oil (any contamination)?
Also... when was the last time the water pump was replaced (and the driveshaft/splines GREASED)?
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Engine oil looks good.
Lower unit lube was changed last October. Looks a little darker than normal, smells like used oil, not fresh but not scorched. No shavings or even metal flakes.
In talking with previous owner, water pump is way overdue. I'm going to do that this weekend. Any tips/tricks?
Running the motor in the driveway with the muffs,I can pinpoint the sound coming from the water pump area.
Just in case, What are the signs and symptoms of the lower end needing rebuilt?
Thank you for your input
Change the water pump, per Service Manual guidelines. Lubricate the splines, and the shaft LARGER diameter area (only) with 2-4-C Grease.
My guess is a very dry bushing in the midsection that is very close in tolerance to the driveshaft.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Thank you Don. Your advice is very much appreciated. I'll check back in with the results
Don, is that bushing metallic or poly? In your experience, how often would it just need grease vs replacement?
I believe it's metallic.
Driveshaft should be lubricated annually (and in a fishing application, it's best to also be replacing the water pump annually).
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Replaced water pump and greased driveshaft this weekend. Seemed to minimize the noise but did not eliminate it. Took it to my local Merc dealer, Just received a call from the tech who did a diagnostic check on the noise. Recommended replacing the driveshaft bushing part #23-859550
It would be nice to have a zerk fitting on that bushing. Just sayin
Probably a good idea to go ahead and replace it, then. Your tech is certainly best equipped to identify "noises" (since he has eyes, ears and hands on the beast).
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Replaced the bushing and it had no effect. Noise actually seems to be getting louder.
I'm getting a really bad feeling about this
Any new developments with this issue?
Funny you should ask. This weekend I replaced all the bearings and seals in the lower unit. Haven't had a chance to run it on the water yet but fired it up with the muffs and it seemed to be gone...
..until it was warmed up. I thought I could hear it slightly coming from the lower crankshaft/upper driveshaft area but it was very slight.
I'm waiting on this windstorm to pass later this week to run it on the lake.
I'll let you all know
Ok, I took the boat out on the lake yesterday and that noise is still there. In this process of elimination, I've changed the water pump, mid shaft bushing and all the bearings and seals in the lower unit.
Yesterday,I was the only one at the boat launch so I was able to pull the cowl while the boat was in the water and shift it in/out of gear with varying rpm.
This was valuable as it eliminated all the excess noise generated while running it in the driveway with muffs. Now it almost seems it's coming from the flywheel area. Possible the sound has been traveling down the driveshaft making it seem it's lower than previously thought.
Really isn't an easy way to diagnose "sounds" or "Noises" by keyboard and monitor.
The closest we can come is perhaps a video, with good audio. Move around slowly while recording, as the changes in camera angle and sound may help in determining the potential sources.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I've got a video of the noise at the dock.
Last edited by tmusky1; 11-11-2017 at 12:39 AM.
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