Squeling 90 Merc

[ddhorner]

I have a 2001 90 merc. Has been a good motor but the last month i get a occasional squeal at low rpms whether in gear or in nuetral. If i throttle up the noise disappears or if I shut the engine off. I cant seem to isolate where the noise is coming from. It may go for hours without making a squeal then start. it mostly has done this after running the engine at higher rpms for a duration. Any opinions on this would be appreciated.

 

[The Marine Doctor]

Re: Squeling 90 Merc

Check the level of the gear oil.<br /><br />Also check for filings.<br /><br />TMD

 

[paulgp6022]

Re: Squeling 90 Merc

Hi, I have a 2003 75 Mercury that does the same thing. It is nothing to worry about as I have learned on this great message board. I have been told it is from the upper bearing on the crank (sounds bad I know). Mercury said it is normal in the 75hp and 90hp (they share the same block). Mine did it after 10 hours, I haven't heard it since. Click on the link below for more info. Enjoy the motor,they are great.<br /><br /> Click here

 

[ddhorner]

Re: Squeling 90 Merc

Thank you for your suggestions. I have noticed this noise after i had taken off airbox to check if that was where i was getting gas leaking in boat when engine is tilted. also pulled plugs on lower unit this morning to check level and filings. with flash light shining on the fluid as it was draining i could see sparkles in the fluid. is this considered normal, like the small amount of filings you might see in a auto transmission change. like i said it sparkles no chunks or large debris i wouldnt even see it if i didnt shine the flashlight directly at the fluid. i am going to change it tonight.

 

[peterbo3]

Re: Squeling 90 Merc

Evening DD,<br />The drain plug on these motors has a small projection on it to capture any loose bits of steel. The whole plug is magnetised.<br />Regards,<br />Peter.

 

[paulgp6022]

Re: Squeling 90 Merc

The squeal isn't from your lower unit. It is from what I mentioned.<br /><br />The glitter in the gear oil is normal. I bought a magnetized drain plug.

 

[ddhorner]

Re: Squeling 90 Merc

thanks again for your responses. i changed lower fluid and set to go. SS minnow i appreciate your insight, so what you are telling me is this is nothing that will be hurtful to the engine? it certainly sounds like a fan belt so im sure we are dealing with the same situation as you. like i said before it happens very seldom but this is my first "real" boat so i get concerned about noises that seem out of the ordinary.

 

[paulgp6022]

Re: Squeling 90 Merc

Yes, you will be fine. The fan belt sound is the same words I used to describe my sound. Good luck.