Whirring sound from engine

[BrentP]

We have had our Sundeck 220 for a couple months. It has 5.0 merc engine.
The other day I noticed a whirring sound at idle RPM, up to maybe 1500. It sounds to go away at higher RPM until slowing back down to no wake and idle speed.

The drive unit oil reservoir was slightly low, and although I pretty much knew that wasn’t the culprit, filled it.

I’m wondering what else it could be. I do have a video just have to figure out how to post it.

Thanks for any thoughts

 

[BrentP]

Hoping this works - You can clearly hear the sound as I cut the engine at the end of the video. Kinda sounds like something sliding across a metal table, a shhhhhhh sound.

Can’t embed the video so maybe posting the link will workhttps://youtube.com/shorts/BtuW-mlPDAc?feature=share

 

[Wanderer 290]

Engine water circulation pump bearing, idler pulley bearing or belt tensioner bearing?
Mechanic’s stethoscope will assist in determining the source of the sound.

Additionally, check the power steering fluid level.

 

[hottoddie]

Engine water circulation pump bearing, idler pulley bearing or belt tensioner bearing?
Mechanic’s stethoscope will assist in determining the source of the sound.

X2. Get a mechanics stethoscope.

 

[Little Ducky]

Are you a DIY'er?

 

[BrentP]

Are you a DIY'er?

Yes, I would want to diagnose and possibly correct myself.

 

[BrentP]

Engine water circulation pump bearing, idler pulley bearing or belt tensioner bearing?
Mechanic’s stethoscope will assist in determining the source of the sound.

Additionally, check the power steering fluid level.

The belt does feel a bit soft, but we’ve only put 10 hours on and it just started making the noise. In my experience with cars, when a belt is loose you get noise at idle but with acceleration it goes away.
Will look at stethoscope

 

[Little Ducky]

Yes, I would want to diagnose and possibly correct myself.

At least with the idler pulley I'd spray a little WD or some other lubricant on the bearing and see if it quiets it down then you know what to replace.

 

[Delta Ron]

If you have more than one belt, remove one at a time, run it to see if the noise goes away. See if you can locate your problem by process of elimination.