Weird sound from engine compartment (video)

[Praesto 25]

Can anyone help me diagnose this potential issue?

 

https://m.youtube.com/watch?v=iyNMyQq36TA

 

Some context:

All fluids look good

All fuses are good

Batteries are good

Fuel water separator is new

 

It makes this sound fairly decently under load and acceleration however the sound becomes much fainter while maintaining a particular speed.

 

It does not make the sound when revving in neutral.

 

The sound randomly started showing up not appearing to be associated with any repair or event.

[boatnut 230]

It kinda sounds low on oil, have you checked that?

How many hours on the engine?

 

[Praesto 25]

Yes oil is good (actually have another post on it on first page ?)

 

I don't remember exact hours but it's a little past 200

[truekaotik 458]

Check your coupler connection to the Vdrive?

 

No noise in neutral rev'd up would make look into the engagement or drive parts..

Edited May 18, 2015 by truekaotik

[Skibumm 184]

I honestly don't know what sounds I am hearing in that. Is it the clunking sound at low RPMs? It also sounds like a lot of wind too in the video. Does the sound ever go completely away? I would not suspect coupler if you are hearing it while in neutral. It kind of sounds like a loose flywheel a bit but that would be very un usual. Check all pulleys and tensioners as well. Could be something loose on the front of the engine.

[Praesto 25]

The belt is nice and tight. I could attempt to get a better video this weekend. The sound is strongly noticable under acceleration and then less obvious while maintaining a speed.

 

The sound you are hearing is very hard for me to explain. But it sounds like a weird "ch ch ch ch ch ch ch ch" That might help follow it in the video. Also ignore the last 5 seconds because that is mostly wind.

[Skibumm 184]

I would remove the belt and check all pulleys and tensioners for play and our roughness. One of those might settle down a bit under a constant load as well and when changing RPMs or at idle be more noticeable. Think about a squealing belt that makes noise at idle and when adding throttle but quiets down when under constant load. Pulleys and tensioners can do that same thing. Not sure the location of your water pump but that could also be a little loose on the bracket or bearing going out in that (depending on type). Once again I am just throwing ideas out there as well.

[boatnut 230]

I totally forgot about the tensioner, but bumm is right, I've seen those fail, it's progressive and it get noisier in the process.. Pull your belt off and check it...

[Praesto 25]

Appreciate it SkiBumm I would like any and all ideas because I would like to take care of this myself if possible without having to pay too much to have to have it fixed.

 

I have another noise that I get when moving at no wake speed. I will post the video here after it uploads to youtube. Not sure if the two are related but they started at the exact same time.

 

 

A little more background information:

I spent a weekend at gaston on the boat for 5 ish hours with everything working perfectly last weekend Saturday the 9th.

This weekend I put it in and the problem was there immediately.

 

Also boat has trouble starting up.

[boatnut 230]

What do you mean trouble starting up? It just keeps cranking or it fires and runs rough?

 

[Praesto 25]

Keeps cranking and cranking and just yesterday cranked the batteries to death resulting in a tow.

[Skibumm 184]

Hmmm. I wonder if you could be seeing something going on with your cap or rotor. IT might be that you have been experiencing a misfire or no fire in more than one cylinder and now you it has progressed until not enough spark to even fire. It might also be fuel related and you were seeing a misfire and now you are not getting enough fuel into more than one cylinder and it won't fire over. Once again just throwing stuff at the wall and hoping something sticks. I would pull your cap first and see if you are seeing any green stuff or corrosion.

[boatnut 230]

Check, plugs, cap, rotor, etc.. I would also put a pressure gauge on the fuel rail....

[truekaotik 458]

I honestly don't know what sounds I am hearing in that. Is it the clunking sound at low RPMs? It also sounds like a lot of wind too in the video. Does the sound ever go completely away? I would not suspect coupler if you are hearing it while in neutral. It kind of sounds like a loose flywheel a bit but that would be very un usual. Check all pulleys and tensioners as well. Could be something loose on the front of the engine.

That video is running in gear on the lake. He stated it doesn't do it in Neutral or Rev'd in Neutral.. This would point to a drive issue most likely.. So if we clear all the drive parts now and it's none, we can proceed to issues under a Load

That's where a sticking pump, pulley, cap/rotor problem can arise as well...

Edited May 18, 2015 by truekaotik

[Praesto 25]

I changed all plugs and the cap and rotor last season, but definitely a short and easy check so I will do that one first. I think a pressure gauge for the fuel rail would be good. How long do the filters generally last?

[truekaotik 458]

That is a loud noise, fuel issues will lead to the knock sensor, if you havnt set that off I would still look outside the engine, not internal.. Cap and rotor causes a miss, not a knock...

Edited May 18, 2015 by truekaotik

[truekaotik 458]

Of course we are all guessing as we aren't at the boat and prolly missing something... I'm still leaning loose or broke part or bolts...

Edited May 18, 2015 by truekaotik

[boatnut 230]

If it's external, could be as simple as something has worked it's way loose and is rubbing on a drive shaft etc.... But it could also be a bent shaft, or a shaft out of. Alignment....

Did you by chance ground the boat..... Or hit something

 

Edited May 18, 2015 by boatnut

[truekaotik 458]

If it's external, could be as simple as something has worked it's way loose and is rubbing on a drive shaft etc.... But it could also be a bent shaft, or a shaft out of. Alignment....

Did you by chance ground the boat..... Or hit something

That will cause driveability issues.. He hasn't mentioned that, it's very noticeable when it occurs.. The boat will shake, cavitate, even with a minor bent prop Edited May 18, 2015 by truekaotik

[Skibumm 184]

That video is running in gear on the lake. He stated it doesn't do it in Neutral or Rev'd in Neutral.. This would point to a drive issue most likely.. So if we clear all the drive parts now and it's none, we can proceed to issues under a Load

That's where a sticking pump, pulley, cap/rotor problem can arise as well...

I missed that part of it. Then if that is the case I would concur that it is post engine in the drive train.