2001 Mercruiser 4.3 Knocking

[EndlessCruiser]

any ideas why it would be knocking so hard.

I was running about 3700rpms on my twin 4.3 Regal 2660. had been running great... wife noticed a wierd noise. I slowed down and engine turned off.. after restart it started vibrating so kept it off until we got to the docks... after I started it again in almost didn't want to start and noticed a slight knock... today I went back to the slip 4 days later and here is the video... a pretty loud noticeable knock.

link

Oil pressure is at 40psi at idle.

it sounds like a bottom end knock.. but not too familiar with this engine.

thoughts...??

thanks in advance...

 

[achris]

That's a bottom end knock, so shut the damn thing down! You're doing more damage just running it!

Pull the spark plugs and do a compression test, that will tell you which piston has a hole in it!

Chris......

 

[Bt Doctur]

Have to agree with Chris. Does have that rythmic tic of a busted /loose rocker arm too. The deep rumbling in the background, noise or exaust in water

 

[Bondo]

Ayuh,.... Welcome Aboard,..... That motor has to come outa the boat, for repairs,.....
I'm guessin' it'll take a new long block, or a bobtail motor to fix that knock,....