Volvo Penta Knocking

[1627]

Hello
My first thread, had my 2010 Rinker 280 5.7 petrol since 2015, my pride and joy, always service and freshwater flush after use trying to try to avoid problems, any way I would be very grateful for any experienced advise, I know I need to go through the regular checks, ie, checking the lifters, pulling the plug leads, compression testing etc, but I am sure some body has had this fault before and may save me a lot of time and effort, so I ask for help diagnosing please.
When cold the engine is perfectly quiet after a few minutes the knock develops an stays consistent with the revs, engine 480 hrs.
Thank you
Barrie.

 

[alldodge]

Not real good sound but sounds to me like a rod knock. Remove the drive and see if the sound is the same.

 

[1627]

Thanks for the input.
Barrie.

 

[stresspoint]

that sounds like something is trying to get out of the sump , where is the oil pressure at ?.

coupling possibly , but i doubt that being it is more a knock than a rattle .

 

[Scott Danforth]

rod knock. most likely bearing is gone and in pieces at the bottom of the sump.

time to pull the drive, then pull the motor and then tear it apart

 

[1627]

Oil pressure perfect.

 

[1627]

on fast tick over

 

[1627]

I would have liked to see the oil pressure very low if the bearing had collapsed?
Also turn the engine off and leave it for a couple of minutes and when re started is quiet for a minute and then starts knocking again. Puzzle.

 

[Scott Danforth]

you could have a lifter that has collapsed leading to a bearing that is now beaten to death.

that would explain why its quiet at first.

either way. motor has to come apart

 

[alldodge]

I depends on which bearing as to oil pressure effect.

Do pull the drive to remove it from the equation to make sure its not coming from it (don't think it is)

 

[matt167]

Perfect time for a 383 upgrade

 

[1627]

Thank you All.

 

[stresspoint]

i had another listen to the knock once i noticed you post with good oil pressure .
I'm wondering if it may be the drive plate broken an arm ( yea i know , best description i could come out with ) , its basically a tin plate with 3 arms if one was to break i recon the sound would be like that in your vid..

 

[1627]

When I get to the boat in a couple weeks (it is a few hours away) I will check all of your suggestions.
Thank you very much

 

[muc]

Remove the serpentine belt and try running it.

 

[QBhoy]

Strange one this, after another listen. Seems to perhaps be not as pronounced or as consistent as a rod knock or similar wound be. Might be totally off the mark here and suspect I am…and perhaps isn’t the typical noise for it…but is your outdrive tilted all the way up and maybe the UJ ?

 

[1627]

Not so crazy a thought, I had just refitted the outdrive.
I will check this first when I get time to go to the boat .
Week or two I will report as may help others.
Thank you.

 

[QBhoy]

Not so crazy a thought, I had just refitted the outdrive.
I will check this first when I get time to go to the boat .
Week or two I will report as may help others.
Thank you.

Worth a look. Sounds like it may well be a mechanical rotational noise Perhaps. Things like the uj knocking can sound all the more amplified when out the water on the trailer too. Best of luck

 

[1627]

After many hours testing this and that, compression test found number 4 cylinder down by 95 psi in comparison to all the rest that were approximately 195 psi.
The endoscope revealed pick up on the cylinder walls and is almost definitely the cause of the nocking.
Removed the outdrive and the nock was exactly the same.
I have removed engine to my home and have received a Volvo Penta factory reman engine and in the process of building it up, will keep you informed.
Merry Christmas
Baz.

 

[Scott Danforth]

After many hours testing this and that, compression test found number 4 cylinder down by 95 psi in comparison to all the rest that were approximately 195 psi.
The endoscope revealed pick up on the cylinder walls and is almost definitely the cause of the nocking.
Removed the outdrive and the nock was exactly the same.
I have removed engine to my home and have received a Volvo Penta factory reman engine and in the process of building it up, will keep you informed.
Merry Christmas
Baz.

check your gauge. any value over 150 psi means debris in the cylinders or a bad gauge. stock motor at 9.4:1 compression has cranking PSI at 150 psi as spec.