Squeal when engine is warm

[JWBC]

Hi,

Just had my 90 hp Mercury 2 stroke tuned. (They adjusted the fuel/air mix). It now runs very well. However since its tune when the engine is warm I hear a squel coming from the lower unit. I hear it come and go while at idle speed. It's sounds like a belt rubbing.

Is it likely to be the drive splines needing some grease or somewhere else? Doesn't seem to affect the engine running.

 

[brandon110]

Re: Squeal when engine is warm

did they put a waterpump kit in it?

 

[JWBC]

Re: Squeal when engine is warm

No,

I replaced the water pump a couple of months ago myself. No issues since changeover of pump. I actually just pulled out the water pump now to inspect. Looks good.

 

[Chris1956]

Re: Squeal when engine is warm

What does the gear oil look like? Is it full of chunks of metal? Remove the waterpump cover and turn the driveshaft. Does it turn smothly, or is a bearing hanging it up?

Last time I heard a squeal from a gearcase, I can home (well almost made it home) in reverse. Forward did not work anymore. I asked the owner when was the last time he changed the gear oil. He answer was "what gear oil".

 

[Texasmark]

Re: Squeal when engine is warm

What does the gear oil look like? Is it full of chunks of metal? Remove the waterpump cover and turn the driveshaft. Does it turn smothly, or is a bearing hanging it up?

Last time I heard a squeal from a gearcase, I can home (well almost made it home) in reverse. Forward did not work anymore. I asked the owner when was the last time he changed the gear oil. He answer was "what gear oil".

Off topic, but gotta add this: Neighbor in his 80's had daughters car over to his house to change the oil after asking her when was the last time she changed her engine oil....her reply: My what?

When he pulled the oil filter nothing came out, nothing. He turned the filter upside down and in shaking it he started to get some goo to shake loose. Whadda deal!!!

Mark

 

[JWBC]

Re: Squeal when engine is warm

What does the gear oil look like? Is it full of chunks of metal? Remove the waterpump cover and turn the driveshaft. Does it turn smothly, or is a bearing hanging it up?

Last time I heard a squeal from a gearcase, I can home (well almost made it home) in reverse. Forward did not work anymore. I asked the owner when was the last time he changed the gear oil. He answer was "what gear oil".

Thanks Chris,

I'll pull out the drive shaft again today and check it. I changed the gear oil about 2 months ago and at that time the oil was clear (no metal). I'll check that also.

 

[JWBC]

Re: Squeal when engine is warm

Hi - Just removed the lower unit and water pump. Drive shaft turns no problems. No unusual sounds. Checked the gear oil - all okay.

Not sure what else to look for now.

PS Greased the drive splines whilst I was at it.

 

[Chris1956]

Re: Squeal when engine is warm

Well, It is time to run it and see if it works. I recommend you stay close to the dock until you are sure it is solid.

 

[M9.9]

Re: Squeal when engine is warm

Hi Op and all,
Suppose the squel may not be from the lower unit? If you have a two-three' piece of narrow tubing, you might consider using it to track down the noise source. By running the engine and holding one end of the tube to an ear and the other against the engine, say--bottom toward top to isolate the area of the noise.

 

[JWBC]

Re: Squeal when engine is warm

Thanks Guys for your assistance. I ran the engine in the back yard for about 10 - 15 mins to get it warm. I had an old stethoscope which I used to run all over the engine. Sounds normal, could'nt hear the noise (frustrating).

I'm taking it out on the bay this weekend (conservatively as suggested by Chris) as I seem to hear it when it is in water. I will use my good video cam to try and record the sound (not sure how successful that will be).

Jim

 

[JWBC]

Re: Squeal when engine is warm

Hi - Took the boat out this afternoon and ran it in the bay to get warm. Reduced to idle and squeal / squeak still present (despite greasing everything I could think of).

I filmed it and uploaded it to YouTube.

(sorry if this link doesn't take you straight there. If not I would appreciate if you cut and pasted to your browser to view!! (New to YouTube.)

I also noted that it only makes the noise in neutral gear. As soon as gears engaged makes no noise.

Any ideas appreciated.

Jim

 

[MercMan82]

Re: Squeal when engine is warm

What year? Sounds like a belt or bearing. Does it have a distributor belt?

 

[JWBC]

Re: Squeal when engine is warm

2000 model. No belt.

 

[MercMan82]

Re: Squeal when engine is warm

I'm no expert by any means, but because the noise is so distinct in the water, it tells me it's not in the lower unit. I'd put money on a bearing.

 

[oldman570]

Re: Squeal when engine is warm

Try checking the vacum lines for pinholes and cracks as they will sometimes whistleand also check for a lose plug. Just a thought.
Oldman570

 

[G8trbait]

Re: Squeal when engine is warm

Well I'm glad I found someone with the same problem I have. I have an 03 90hp, but mine only has that noise when I run at 30+ mph and goes away after about 30 secs of being off a plane. If I run only 26 mph it won't do it??!!! My friend said I'll know what it is when it breaks :-( Good Luck I'll try the vac lines thanks for the info.

 

[JWBC]

Re: Squeal when engine is warm

Took it to the marine mechanics today who ran it in the tank for quite a while to replicate the sound. Wouldn't make the same sound for them but they did find that the 5 nuts on the lower leg were not properly tightened (may have to own up to that!) and the thread appeared to be partly worn. In the absence of any identifiable reason (and they think it is a long shot) but it may have been rubbing?. Anyway, thanks for your various advice, very much appreciated. Will try it on the bay and see how it goes.

PS As an interesting aside they spent a fair bit of time with it in the tank but didn't charge me a cent because they couldn't be sure of the problem!!!.

 

[G8trbait]

Re: Squeal when engine is warm

here is another thread that sounds like the same problem with a different solution. Good luck

http://forums.iboats.com/showthread.php?t=307344

 

[Gildav]

Re: Squeal when engine is warm

here is another thread that sounds like the same problem with a different solution. Good luck

http://forums.iboats.com/showthread.php?t=307344

I have a mint 2005 6hp 4 stroke Merc that has an intermittent squeal, at idle. this O/B has only done a few hours and I am now starting to think the noise is coming from the leg. I have removed the sparkplug so I can turn the engine over easy and the squeak is there. I will drop the leg off and try and isolate whether it is the engine or gearbox. Gearbox oil is definately good.